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Sample records for da leishmania amazonensis

  1. Experimental mixed infection of Leishmania (Leishmania) amazonensis and Leishmania (L.) infantum in hamsters (Mesocricetus auratus).

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    DE Lima Celeste, Jordanna Luíza; Venuto Moura, Ana Paula; França-Silva, João Carlos; Matos DE Sousa, Gabriela; Oliveira Silva, Soraia; Norma Melo, Maria; Luiz Tafuri, Wagner; Carvalho Souza, Carolina; Monteiro DE Andrade, Hélida

    2017-08-01

    In South America, visceral leishmaniasis is frequently caused by Leishmania infantum and, at an unknown frequency, by Leishmania amazonensis. Therefore, mixed infections with these organisms are possible. Mixed infections might affect the clinical course, immune response, diagnosis, treatment and epidemiology of the disease. Here we describe the clinical course of mixed infections with L. amazonensis and L. infantum in a hamster model. We show that mixed infections are associated with more severe clinical disease than infection with L. amazonensis or L. infantum alone. In spleens with mixed infections, L. infantum outcompeted L. amazonensis in the tissue, but not in culture from tissue. We found increased levels of IgG in animals infected with L. infantum. Although more than 30 bands were revealed in a Western blot, the highest immunogenicity was observed with proteins having molecular masses of 95 and 90 kDa, whereas proteins with molecular masses of lower than 50 kDa were reactive frequently with serum from hamsters infected with L. amazonensis, and proteins with molecular masses of 80 and 70 kDa were reactive only with serum from hamsters infected with L. infantum. This finding has important implications regarding the biology of Leishmania and humoral immune responses to infections with these organisms.

  2. Histopatologia da forma localizada de leishmaniose cutânea por Leishmania (Leishmania amazonensis Histopathology of the localized form of cutaneous leishmaniasis due to Leishmania (Leishmania amazonensis

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    Mário A. P. Moraes

    1994-10-01

    Full Text Available São descritas as alterações microscópicas presentes na forma localizada (ulcerada da Leishmaniose cutânea produzida por Leishmania (Leishmania amazonensis. Nesse tipo de manifestação, menos conhecido do que a forma anérgica ou difusa devida ao mesmo agente, as lesões são clinicamente idênticas às de leishmaniose cutânea causada por espécies outras de Leishmania, pertencentes ao subgênero Viannia. Na infecção localizada por L. (L. amazonensis, entretanto, há um aspecto peculiar, só recentemente conhecido, ou seja, cerca de 50% dos indivíduos atingidos não reagem ao teste de Montenegro. A principal característica histológica observada foi a acumulação na derme, quase sempre focal, de numerosos macrófagos contendo no citoplasma um grande vacúolo cheio de amastigotas. O quadro é semelhante ao da forma difusa, porém sem o aspecto histiocitomatóide, próprio da última. Afora esses grupos de macrófagos, vêem-se também, na forma localizada, muitas células mononucleares da inflamação, principalmente plasmócitos e macrófagos não parasitados. Os acúmulos de macrófagos com amastigotas, quando volumosos, podem sofrer necrose na parte central; os parasitos, contidos nas células, são destruídos com elas ou liberados, e sua eliminação através da úlcera deve contribuir para a cura do processo. Esse tipo de necrose nunca foi descrito em casos da forma difusa. Não houve grande diferença, no quadro histológico, entre pacientes Montenegro-negativos e positivos. Apenas em alguns casos, do grupo Montenegro-positivo, havia granulomas formados por histiócitos epitelióides sem parasitos. Quanto à persistência das células com parasitos nas lesões, observou-se que aos seis meses ou mais de evolução, em ambos os grupos, ainda estavam elas presentes. Tal achado não é comum na leishmaniose tegumentar por L. (V. braziliensis.The microscopic changes found in the localized form of the human cutaneous leishmaniasis due

  3. Experimental treatment with sodium stibogluconate of hamsters infected with Leishmania (Leishmania) chagasi and Leishmania (Leishmania) amazonensis Tratamento experimental com stibogluconato de sódio em hamsters infectados com Leishmania (Leishmania) chagasi e Leishmania (Leishmania) amazonensis

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    Elizabeth M. de Figueiredo; Jaime Costa e Silva; Reginaldo P. Brazil

    1999-01-01

    The present paper reports the experimental treatment of hamsters infected with Leishmania chagasi and Leishmania amazonensis with sodium stibogluconate (20mg/kg/day x 20 days). Only with L. chagasi did the treatment result in the complete elimination of parasites from the spleen. However, no parasitological cure was achieved in hamsters infected with L. amazonensis.O presente trabalho é um relato do tratamento experimental de hamsters infectado com Leishmania chagasi e Leishmania amazonensis ...

  4. Persistence of Leishmania antigen in C57Bl/6j inbred mice infected with Leishmania (Leishmania amazonensis Persistência do antígeno da Leishmania no camundongo isogênico C57Bl/6j infectado com a Leishmania (Leishmania amazonensis

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    C. Vasconcellos

    1999-07-01

    Full Text Available PURPOSE. To develop an animal model for studying mucocutaneous leishmaniasis. METHODS. The hind footpad of C57Bl/6j inbred mice was experimentally infected with 10(7 Leishmania (Leishmania amazonensis promastigote and the skin was studied through light and electron transmission microscopy and immunohistochemistry (PAP techniques. RESULTS. There were morphological evidences of cellular immune mechanisms and hypersensitivity reaction after eight weeks of infection and metastasis and well shaped parasites at ultrastructural level by fifty-one weeks post infection. Relapse of infection with mucosa lesions occurred around the 50th week after inoculation. CONCLUSION. The use of this animal model in long term follow up could be an useful experimental model for human mucocutaneous leishmaniasis.OBJETIVO. Desenvolver um modelo experimental para o estudo da leishmaniose cutâneo-mucosa. MÉTODOS. O coxim plantar traseiro de camundongos isogênicos C57Bl/6j foi inoculado com 10(7 formas promastigotas da Leishmania (Leishmania amazonensis e a pele foi estudada através da microscopia óptica e eletrônica e de técnica imunohistoquímica (PAP. RESULTADOS. Ocorreram evidências morfológicas de mecanismos imunes mediados por células, concomitantemente ao de reação de hipersensibilidade, após a oitava semana de infecção e a presença de parasitas com ultraestrutura preservada na quinquagésima primeira semana após a infecção. Houve recidiva da infecção com surgimento de lesões mucosas por volta da 50a semana pós inoculação. CONCLUSÃO. Este modelo animal, com um período de tempo de seguimento prolongado, poderia ser empregado como modelo para o estudo experimental da leishmaniose cutâneo-mucosa.

  5. A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster

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    Sinagra, Ángel; Luna, Concepción; Abraham, David; Iannella, Maria del Carmen; Riarte, Adelina; Krolewiecki, Alejandro J.

    2007-01-01

    New therapeutic alternatives against leishmaniasis remain a priority. The activity of azithromycin against Leishmania (Leishmania) major has been previously demonstrated. Different responses among species of Leishmania make species-specific drug screening necessary. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with unt...

  6. Subcellular localization of an intracellular serine protease of 68 kDa in Leishmania (Leishmania amazonensis promastigotes

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    José Andrés Morgado-Díaz

    2005-07-01

    Full Text Available Here we report the subcellular localization of an intracellular serine protease of 68 kDa in axenic promastigotes of Leishmania (Leishmania amazonensis, using subcellular fractionation, enzymatic assays, immunoblotting, and immunocytochemistry. All fractions were evaluated by transmission electron microscopy and the serine protease activity was measured during the cell fractionation procedure using a-N-r-tosyl-L-arginine methyl ester (L-TAME as substrate, phenylmethylsulphone fluoride (PMSF and L-1-tosylamino-2-phenylethylchloromethylketone (TPCK as specific inhibitors. The enzymatic activity was detected mainly in a membranous vesicular fraction (6.5-fold enrichment relative to the whole homogenate, but also in a crude plasma membrane fraction (2.0-fold. Analysis by SDS-PAGE gelatin under reducing conditions demonstrated that the major proteolytic activity was found in a 68 kDa protein in all fractions studied. A protein with identical molecular weight was also recognized in immunoblots by a polyclonal antibody against serine protease (anti-SP, with higher immunoreactivity in the vesicular fraction. Electron microscopic immunolocalization using the same polyclonal antibody showed the enzyme present at the cell surface, as well as in cytoplasmic membranous compartments of the parasite. Our findings indicate that the internal location of this serine protease in L. amazonensis is mainly restricted to the membranes of intracellular compartments resembling endocytic/exocytic elements.

  7. Novel selective inhibitor of Leishmania (Leishmania) amazonensis arginase.

    Science.gov (United States)

    da Silva, Edson R; Boechat, Nubia; Pinheiro, Luiz C S; Bastos, Monica M; Costa, Carolina C P; Bartholomeu, Juliana C; da Costa, Talita H

    2015-11-01

    Arginase is a glycosomal enzyme in Leishmania that is involved in polyamine and trypanothione biosynthesis. The central role of arginase in Leishmania (Leishmania) amazonensis was demonstrated by the generation of two mutants: one with an arginase lacking the glycosomal addressing signal and one in which the arginase-coding gene was knocked out. Both of these mutants exhibited decreased infectivity. Thus, arginase seems to be a potential drug target for Leishmania treatment. In an attempt to search for arginase inhibitors, 29 derivatives of the [1,2,4]triazolo[1,5-a]pyrimidine system were tested against Leishmania (Leishmania) amazonensis arginase in vitro. The [1,2,4]triazolo[1,5-a]pyrimidine scaffold containing R1  = CF3 exhibited greater activity against the arginase rather than when the substituent R1  = CH3 in the 2-position. The novel compound 2-(5-methyl-2-(trifluoromethyl)-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)hydrazinecarbothioamide (30) was the most potent, inhibiting arginase by a non-competitive mechanism, with the Ki and IC50 values for arginase inhibition estimated to be 17 ± 1 μm and 16.5 ± 0.5 μm, respectively. These results can guide the development of new drugs against leishmaniasis based on [1,2,4]triazolo[1,5-a]pyrimidine derivatives targeting the arginase enzyme. © 2015 John Wiley & Sons A/S.

  8. Leishmania mexicana amazonensis: heterogeneity in 5-nucleotidase and peroxidase activities of mononuclear phagocytes during in vivo and in vitro infection Leishmania mexicana amazonensis: heterogeneidade da 5’-Nucleotidase e da peroxidase em fagócitos mononucleares durante infecção in vivo e in vitro

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    Suzana Côrte-Real

    1988-03-01

    Full Text Available The degree of maturation of cells of the Mononuclear Phagocyte System (MPS, during in vivo and in vitro infection by Leishmania mexicana amazonenesis, was evaluated in this study. The macrophages' differentiation was assayed by cytochemical characterization at the ultrastrctural level, using two well-established markers: 5'-nucleotidase enzyme activity, for revealing the mature cells, and the peroxidase activity present in the cell granules to demonstrate immature mononuclear phagocytes. only a few mcrophages, demonstrating 5'-nucleotidase positive reaction in both the plasma membrane and within their cytoplasmic vesicles, were found scattered in the chronic inflammation at the L. m. amazonensis lesions in albino mice. However, by the peroxidase activity analysis, we were also able to demonstrate the presence of immature MPS cells, which predominate, together with parasitized vacuolated macrophages, in chronic lesions induced in this systemby L. m. amazonensis. The implications of these results on the pathogenesis of murine cutaneous leishmaniasis are discussed.Um estudo sobre o grau de maturação das células do Sistema Fagocítico Mononuclear foi realizado durante a infecção in vivo e in vitro com a Leishmania mexicana amazonensis. A caracterização da diferenciação das células fagocíticas foi obtida com a localização ultraestrutural de dois marcadores enzimáticos bam conhecidos: a enzima 5'-Nucleotidase marcadora de membrana plasmática de células maduras e a enzima peroxidase, presente em grânulos, marcadora de células imaturas. A atividade da enzima 5'-Nucleotidase foi encontrada apenas em alguns macrófagos, presentes no foco inflamatório, em projeções da membrana plasmática e em algumas vesículas citoplasmáticas. Macrófagos peritoneais de camundongo apresentaram a mesma reatividade para este marcador. Contudo a análise da atividade peroxidásica demonstrou a predominância da presença de fagócitos mononucleares

  9. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis.

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    Acuña, Stephanie Maia; Aoki, Juliana Ide; Laranjeira-Silva, Maria Fernanda; Zampieri, Ricardo Andrade; Fernandes, Juliane Cristina Ribeiro; Muxel, Sandra Marcia; Floeter-Winter, Lucile Maria

    2017-01-01

    Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fate of Leishmania infection. The transcriptomic profiling identified a family of oxidoreductases in L. (L.) amazonensis wild-type (La-WT) and L. (L.) amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. We highlighted the identification of an oxidoreductase that could act as nitric oxide synthase-like (NOS-like), due to the following evidences: conserved domain composition, the participation of NO production during the time course of promastigotes growth and during the axenic amastigotes differentiation, regulation dependence on arginase activity, as well as reduction of NO amount through the NOS activity inhibition. NO quantification was measured by DAF-FM labeling analysis in a flow cytometry. We described an arginase-dependent NOS-like activity in L. (L.) amazonensis and its role in the parasite growth. The increased detection of NO production in the mid-stationary and late-stationary growth phases of La-WT promastigotes could suggest that this production is an important factor to metacyclogenesis triggering. On the other hand, La-arg- showed an earlier increase in NO production compared to La-WT, suggesting that NO production can be arginase-dependent. Interestingly, La-WT and La-arg- axenic amastigotes produced higher levels of NO than those observed in promastigotes. As a conclusion, our work suggested that NOS-like is expressed in Leishmania in the stationary growth phase promastigotes and amastigotes, and could be correlated to metacyclogenesis and amastigotes growth in a dependent way to the internal pool of L-arginine and arginase activity.

  10. Neutrophils reduce the parasite burden in Leishmania (Leishmania amazonensis-infected macrophages.

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    Erico Vinícius de Souza Carmo

    2010-11-01

    Full Text Available Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L major, whereas less information is available for L. (L amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L. amazonensis (C3H/HePas. In contrast, the susceptible strain (BALB/c displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L. amazonensis-infected macrophages in vitro.Mouse peritoneal macrophages infected with L. (L. amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. The main findings were 1 intracellular parasites were efficiently destroyed in the co-cultures; 2 the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas or susceptible (BALB/c to L. (L. amazonensis; 3 parasite destruction did not require contact between infected macrophages and neutrophils; 4 tumor necrosis factor alpha (TNF-α, neutrophil elastase and platelet activating factor (PAF were involved with the leishmanicidal activity, and 5 destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-α, as reported for other Leishmania species.The present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L. amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.

  11. The Genome Sequence of Leishmania (Leishmania) amazonensis: Functional Annotation and Extended Analysis of Gene Models

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    Real, Fernando; Vidal, Ramon Oliveira; Carazzolle, Marcelo Falsarella; Mondego, Jorge Maurício Costa; Costa, Gustavo Gilson Lacerda; Herai, Roberto Hirochi; Würtele, Martin; de Carvalho, Lucas Miguel; e Ferreira, Renata Carmona; Mortara, Renato Arruda; Barbiéri, Clara Lucia; Mieczkowski, Piotr; da Silveira, José Franco; Briones, Marcelo Ribeiro da Silva; Pereira, Gonçalo Amarante Guimarães; Bahia, Diana

    2013-01-01

    We present the sequencing and annotation of the Leishmania (Leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the Amazon region of Brazil. L. (L.) amazonensis shares features with Leishmania (L.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). Predicted genes were scored for orthologous gene families and conserved domains in comparison with other human pathogenic Leishmania spp. Carboxypeptidase, aminotransferase, and 3′-nucleotidase genes and ATPase, thioredoxin, and chaperone-related domains were represented more abundantly in L. (L.) amazonensis and L. (L.) mexicana species. Phylogenetic analysis revealed that these two species share groups of amastin surface proteins unique to the genus that could be related to specific features of disease outcomes and host cell interactions. Additionally, we describe a hypothetical hybrid interactome of potentially secreted L. (L.) amazonensis proteins and host proteins under the assumption that parasite factors mimic their mammalian counterparts. The model predicts an interaction between an L. (L.) amazonensis heat-shock protein and mammalian Toll-like receptor 9, which is implicated in important immune responses such as cytokine and nitric oxide production. The analysis presented here represents valuable information for future studies of leishmaniasis pathogenicity and treatment. PMID:23857904

  12. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model

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    Sinagra,Ángel; Luna,Concepción; Abraham,David; Iannella,Maria del Carmen; Riarte,Adelina; Krolewiecki,Alejandro J.

    2007-01-01

    New therapeutic alternatives against leishmaniasis remain a priority. The activity of azithromycin against Leishmania (Leishmania) major has been previously demonstrated. Different responses among species of Leishmania make species-specific drug screening necessary. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with unt...

  13. Cell migration induced by Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) major and Leishmania (Viannia) braziliensis into the peritoneal cavity of BALB/c mice

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    DT Wakimoto; KV Gaspareto; TGV Silveira; MVC Lonardoni; SMA Aristides

    2010-01-01

    In American cutaneous leishmaniasis, the initial infection phase is characterized by recruitment of neutrophils and monocytes. The migration of these cells in response to the presence of Leishmania in the peritoneum of affected animals remains unclear. The objective of this study was to investigate cell migration to the peritoneum of BALB/c mice after infection with Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) major. Initially, Leishmania ...

  14. Inhibition of growth of Leishmania mexicana mexicana by Leishmania mexicana amazonensis during "in vitro" co-cultivation Inibição do crescimento de Leishmania mexicana mexicana por Leishmania mexicana amazonensis durante o co-cultivo "in vitro"

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    Raquel S. Pacheco

    1987-12-01

    Full Text Available Inhibition of one Leishmania subspecies by exometabolites of another subspecies, a phenomenon not previously reported, is suggested by our recent observations in cell cloning experiments with Leishmania mexicana mexicana and Leishmania mexicana amazonensis. Clones were identified using the technique of schizodeme analysis. The phenomenon observed is clearly relevant to studies of parasite isolation, leishmanial metabolism, cross-immunity and chemotherapy.Inhibição do crescimento de um subespécie de Leishmania por exometabólitos de outra subespécie, um fenômeno ainda não notificado, é sugerido em nossas recentes observações em experimentos de clonagem celular com Leishmania mexicana mexicana e Leishmania mexicana amazonensis. Os clones foram identificados usando a técnica de análise de esquizodemas. O fenômeno observado é claramente relevante em estudos de isolamento parasitário, metabolismo, imunidade cruzada e quimioterapia.

  15. LaRbp38: A Leishmania amazonensis protein that binds nuclear and kinetoplast DNAs

    International Nuclear Information System (INIS)

    Lira, C.B.B.; Siqueira Neto, J.L.; Giardini, M.A.; Winck, F.V.; Ramos, C.H.I.; Cano, M.I.N.

    2007-01-01

    Leishmania amazonensis causes a wide spectrum of leishmaniasis. There are no vaccines or adequate treatment for leishmaniasis, therefore there is considerable interest in the identification of new targets for anti-leishmania drugs. The central role of telomere-binding proteins in cell maintenance makes these proteins potential targets for new drugs. In this work, we used a combination of purification chromatographies to screen L. amazonensis proteins for molecules capable of binding double-stranded telomeric DNA. This approach resulted in the purification of a 38 kDa polypeptide that was identified by mass spectrometry as Rbp38, a trypanosomatid protein previously shown to stabilize mitochondrial RNA and to associate with nuclear and kinetoplast DNAs. Western blotting and supershift assays confirmed the identity of the protein as LaRbp38. Competition and chromatin immunoprecipitation assays confirmed that LaRbp38 interacted with kinetoplast and nuclear DNAs in vivo and suggested that LaRbp38 may have dual cellular localization and more than one function

  16. Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania amazonensis in the state of Mato Grosso do Sul, mid-western Brazil Capturas de flebotomíneos com armadilhas de Disney em área de ocorrência de Leishmania (Leishmania amazonensis no estado de Mato Grosso do Sul, região Centro-Oeste do Brasil

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    Maria Elizabeth Cavalheiros Dorval

    2010-10-01

    Full Text Available INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3% and Bi flaviscutellata (41.4%, present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania amazonensis, situada no município de Bela Vista, Estado do Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus auratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae

  17. Vector Competence of Lutzomyia cruzi Naturally Demonstrated for Leishmania infantum and Suspected for Leishmania amazonensis.

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    de Oliveira, Everton Falcão; Oshiro, Elisa Teruya; Fernandes, Wagner Souza; Ferreira, Alda Maria Teixeira; de Oliveira, Alessandra Gutierrez; Galati, Eunice Aparecida Bianchi

    2017-01-11

    Corumbá city is one of the oldest visceral leishmaniasis-endemic foci in the state of Mato Grosso do Sul, Brazil, where the transmission of Leishmania infantum has been attributed to Lutzomyia cruzi Aiming at investigating the parameters of the vectorial capacity of Lu. cruzi for L. infantum, a project was undertaken in this city. Among these parameters, vector competence was investigated and the results obtained are reported herein. Of the 12 hamsters exposed to feed wild-caught female sandflies, two developed infection with L. infantum and surprisingly, one with Leishmania amazonensis In addition, hamsters with L. infantum infection were bitten only by females of Lu. cruzi, whereas the hamster infected with L. amazonensis was bitten by 124 Lu. cruzi females and one of Evandromyia corumbaensis Although there is a strong suspicion regarding the competence of Lu. cruzi in transmitting L. amazonensis naturally, it was not demonstrated. © The American Society of Tropical Medicine and Hygiene.

  18. The use of kDNA minicircle subclass relative abundance to differentiate between Leishmania (L.) infantum and Leishmania (L.) amazonensis.

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    Ceccarelli, Marcello; Galluzzi, Luca; Diotallevi, Aurora; Andreoni, Francesca; Fowler, Hailie; Petersen, Christine; Vitale, Fabrizio; Magnani, Mauro

    2017-05-16

    Leishmaniasis is a neglected disease caused by many Leishmania species, belonging to subgenera Leishmania (Leishmania) and Leishmania (Viannia). Several qPCR-based molecular diagnostic approaches have been reported for detection and quantification of Leishmania species. Many of these approaches use the kinetoplast DNA (kDNA) minicircles as the target sequence. These assays had potential cross-species amplification, due to sequence similarity between Leishmania species. Previous works demonstrated discrimination between L. (Leishmania) and L. (Viannia) by SYBR green-based qPCR assays designed on kDNA, followed by melting or high-resolution melt (HRM) analysis. Importantly, these approaches cannot fully distinguish L. (L.) infantum from L. (L.) amazonensis, which can coexist in the same geographical area. DNA from 18 strains/isolates of L. (L.) infantum, L. (L.) amazonensis, L. (V.) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, and 62 clinical samples from L. (L.) infantum-infected dogs were amplified by a previously developed qPCR (qPCR-ML) and subjected to HRM analysis; selected PCR products were sequenced using an ABI PRISM 310 Genetic Analyzer. Based on the obtained sequences, a new SYBR-green qPCR assay (qPCR-ama) intended to amplify a minicircle subclass more abundant in L. (L.) amazonensis was designed. The qPCR-ML followed by HRM analysis did not allow discrimination between L. (L.) amazonensis and L. (L.) infantum in 53.4% of cases. Hence, the novel SYBR green-based qPCR (qPCR-ama) has been tested. This assay achieved a detection limit of 0.1 pg of parasite DNA in samples spiked with host DNA and did not show cross amplification with Trypanosoma cruzi or host DNA. Although the qPCR-ama also amplified L. (L.) infantum strains, the C q values were dramatically increased compared to qPCR-ML. Therefore, the combined analysis of C q values from qPCR-ML and qPCR-ama allowed to distinguish L. (L.) infantum and L. (L.) amazonensis in 100% of tested samples

  19. Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania) amazonensis, but Not by Leishmania (Viannia) guyanensis.

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    DaMata, Jarina Pena; Mendes, Bárbara Pinheiro; Maciel-Lima, Kátia; Menezes, Cristiane Alves Silva; Dutra, Walderez Ornelas; Sousa, Lirlândia Pires; Horta, Maria Fátima

    2015-01-01

    Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6), whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection.

  20. Distinct Macrophage Fates after in vitro Infection with Different Species of Leishmania: Induction of Apoptosis by Leishmania (Leishmania amazonensis, but Not by Leishmania (Viannia guyanensis.

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    Jarina Pena DaMata

    Full Text Available Leishmania is an intracellular parasite in vertebrate hosts, including man. During infection, amastigotes replicate inside macrophages and are transmitted to healthy cells, leading to amplification of the infection. Although transfer of amastigotes from infected to healthy cells is a crucial step that may shape the outcome of the infection, it is not fully understood. Here we compare L. amazonensis and L. guyanensis infection in C57BL/6 and BALB/c mice and investigate the fate of macrophages when infected with these species of Leishmania in vitro. As previously shown, infection of mice results in distinct outcomes: L. amazonensis causes a chronic infection in both strains of mice (although milder in C57BL/6, whereas L. guyanensis does not cause them disease. In vitro, infection is persistent in L. amazonensis-infected macrophages whereas L. guyanensis growth is controlled by host cells from both strains of mice. We demonstrate that, in vitro, L. amazonensis induces apoptosis of both C57BL/6 and BALB/c macrophages, characterized by PS exposure, DNA cleavage into nucleosomal size fragments, and consequent hypodiploidy. None of these signs were seen in macrophages infected with L. guyanensis, which seem to die through necrosis, as indicated by increased PI-, but not Annexin V-, positive cells. L. amazonensis-induced macrophage apoptosis was associated to activation of caspases-3, -8 and -9 in both strains of mice. Considering these two species of Leishmania and strains of mice, macrophage apoptosis, induced at the initial moments of infection, correlates with chronic infection, regardless of its severity. We present evidence suggestive that macrophages phagocytize L. amazonensis-infected cells, which has not been verified so far. The ingestion of apoptotic infected macrophages by healthy macrophages could be a way of amastigote spreading, leading to the establishment of infection.

  1. Natural infection of phlebotomines (Diptera: Psychodidae) by Leishmania (Leishmania) amazonensis in an area of ecotourism in Central-Western Brazil.

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    Brilhante, Andreia Fernandes; Nunes, Vânia Lúcia Brandão; Kohatsu, Kleber Augusto; Galati, Eunice Aparecida Bianchi; Rocca, Maria Elizabeth Ghizzi; Ishikawa, Edna Aoba Yassui

    2015-01-01

    Bonito municipality, known as an area of ecoturism, in Mato Grosso do Sul state, Brazil, is also a focus of visceral and cutaneous leishmaniases, with cases registered in both human and canine populations. This study sought to investigate natural infection by flagellate forms of Leishmania in phlebotomines of the urban area of Bonito. Sand flies were collected fortnightly from October 2005 to July 2006 with modified automatic light traps installed in peridomiciles and animal shelters in the center and on the outskirts of the city. The females were dissected and their guts observed under an optical microscope. A total of 1977 specimens were captured, Lutzomyia longipalpis (88.4 %) and Bichromomyia flaviscutelata (3.0 %) being the most frequent species. Bi. flaviscutellata was found infected by flagellates that were identified as Leishmania (Leishmania) amazonensis by indirect immunofluorescence reaction, employing monoclonal antibodies and the biotin-avidin system. This is the first report of natural infection by L. amazonensis in Bi. flaviscutellata in a Brazilian urban area. As Bi. flaviscutellata is only slightly attracted by humans, the transmission of L. amazonensis in the study area may have a zoonotic character; however, the sympatric occurrence of this parasite and Lu. longipalpis should be taken into consideration by the local health authorities since this sand fly has already been found with L. amazonensis DNA in a focus of canine visceral leishmaniasis in Bonito municipality.

  2. Natural canine infection by Leishmania infantum and Leishmania amazonensis and their implications for disease control

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    Letícia da Cruz Sanches

    Full Text Available Abstract Leishmaniasis is a major public health problem worldwide. Because Leishmania can adapt to new hosts or vectors, knowledge concerning the current etiological agent in dogs is important in endemic areas. This study aimed to identify the Leishmania species detected in 103 samples of peripheral blood from dogs that were naturally infected with these protozoa. The diagnosis of leishmaniasis was determined through parasitological examination, the indirect enzyme-linked immunosorbent assay (ELISA and the polymerase chain reaction (PCR. The Leishmania species were identified by means of PCR-restriction fragment length polymorphism (PCR-RFLP. The samples were subjected to PCR using oligonucleotide primers that amplify the intergenic region ITS1 of the rRNA gene in order to identify the species. The amplified DNA was digested using the restriction enzyme HaeIII. A restriction profile identical to L. amazonensis was shown in 77/103 samples and the profile was similar to L. infantum in 17/103. However, a mixed profile was shown in 9/103 samples, which impeded species identification. In conclusion, the infection in these dogs was predominantly due to L. amazonensis, thus indicating that diagnosing of cases of canine leishmaniasis needs to be reexamined, since the causative agent identified is not restricted to L. infantum.

  3. Protection of C57BL/10 mice by vaccination with association of purified proteins from Leishmania (Leishmania amazonensis

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    MORA Ana Mariela

    1999-01-01

    Full Text Available In the past few years, induction of protective immunity to cutaneous leishmaniasis has been attempted by many researchers using a variety of antigenic preparations, such as living promastigotes or promastigote extracts, partially purified, or defined proteins. In this study, eleven proteins from Leishmania (Leishmania amazonensis (LLa with estimated molecular mass ranging from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and electro-elution. The proteins were associated as vaccine in different preparations with gp63 and BCG (Bacilli Calmette-Guérin. The antigenicity of these vaccines was measured by their ability to induce the production of IFN-g by lymphocyte from subjects vaccinated with Leishvacinâ . The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were vaccinated with three doses of each vaccine consisting of 30 mg of each protein at 15 days interval. One hundred mg of live BCG was only used in the first dose. Seven days after the last dose, they received a first challenge infection with 105 infective promastigotes and four months later, a second challenge was done. Two months after the second challenge, 42.86% of protection was obtained in the group of mice vaccinated with association of proteins of gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa; 57.14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa, gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of gp63+46+40kDa that did not protect the mice, despite the good specific stimulation of lymphocytes (LSI = 7.60 and 10.77UI/ml of IFN-g production. When crude extract of L. (L. amazonensis was used with BCG a 57.14% of protection was found after the first challenge and 28.57% after the second, the same result was observed for gp63. The data obtained with the vaccines can suggest that the future vaccine probably have to contain, except the 40kDa, a cocktail of proteins that

  4. Crotoxin stimulates an M1 activation profile in murine macrophages during Leishmania amazonensis infection.

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    Farias, L H S; Rodrigues, A P D; Coêlho, E C; Santos, M F; Sampaio, S C; Silva, E O

    2017-09-01

    American tegumentary leishmaniasis is caused by different species of Leishmania. This protozoan employs several mechanisms to subvert the microbicidal activity of macrophages and, given the limited efficacy of current therapies, the development of alternative treatments is essential. Animal venoms are known to exhibit a variety of pharmacological activities, including antiparasitic effects. Crotoxin (CTX) is the main component of Crotalus durissus terrificus venom, and it has several biological effects. Nevertheless, there is no report of CTX activity during macrophage - Leishmania interactions. Thus, the main objective of this study was to evaluate whether CTX has a role in macrophage M1 polarization during Leishmania infection murine macrophages, Leishmania amazonensis promastigotes and L. amazonensis-infected macrophages were challenged with CTX. MTT [3-(4,5dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] toxicity assays were performed on murine macrophages, and no damage was observed in these cells. Promastigotes, however, were affected by treatment with CTX (IC50 = 22·86 µg mL-1) as were intracellular amastigotes. Macrophages treated with CTX also demonstrated increased reactive oxygen species production. After they were infected with Leishmania, macrophages exhibited an increase in nitric oxide production that converged into an M1 activation profile, as suggested by their elevated production of the cytokines interleukin-6 and tumour necrosis factor-α and changes in their morphology. CTX was able to reverse the L. amazonensis-mediated inhibition of macrophage immune responses and is capable of polarizing macrophages to the M1 profile, which is associated with a better prognosis for cutaneous leishmaniasis treatment.

  5. Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis Efeito combinado do óleo de essência de Chenopodium ambrosioides e drogas anti-leishmaniose nos promastigotas de Leishmania amazonensis

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    Lianet Monzote

    2007-08-01

    Full Text Available To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against promastigotes of Leishmania amazonensis. However, an indifferent effect has been found for combinations of meglumine antimoniate or amphotericin B and the essential oil.Até hoje não temos vacina contra a Leishmania e a quimioterapia é a indicação para o controle desta doença. Os remédios que hoje utilizamos são tóxicos e muito caros e além disso o resultado não é sempre o desejado. Por isso, uma terapia de combinação é a melhor opção. Este trabalho mostra que o óleo de essência de C. ambrosioides tem atividade sinérgica junto com a pentamidina sobre os promastigotas de L. amazonensis, diferente do resultado da combinação de antimônio de meglumine e anfotericina B e o óleo de essência.

  6. In vivo and in vitro phagocytosis of Leishmania (Leishmania) amazonensis promastigotes by B-1 cells.

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    Geraldo, M M; Costa, C R; Barbosa, F M C; Vivanco, B C; Gonzaga, W F K M; Novaes E Brito, R R; Popi, A F; Lopes, J D; Xander, P

    2016-06-01

    Leishmaniasis is caused by Leishmania parasites that infect several cell types. The promastigote stage of Leishmania is internalized by phagocytic cells and transformed into the obligate intracellular amastigote form. B-1 cells are a subpopulation of B cells that are able to differentiate in vitro and in vivo into mononuclear phagocyte-like cells with phagocytic properties. B-1 cells use several receptors for phagocytosis, such as the mannose receptor and third complement receptor. Leishmania binds to the same receptors on macrophages. In this study, we demonstrated that phagocytes derived from B-1 cells (B-1 CDP) were able to internalize promastigotes of L. (L.) amazonensis in vitro. The internalized promastigotes differentiated into amastigotes. Our results showed that the phagocytic index was higher in B-1 CDP compared to peritoneal macrophages and bone marrow-derived macrophages. The in vivo phagocytic ability of B-1 cells was also demonstrated. Parasites were detected inside purified B-1 cells after intraperitoneal infection with L. (L.) amazonensis promastigotes. Intraperitoneal stimulation with the parasites led to an increase in both IL-10 and TNF-α. These results highlight the importance of studying B-1 CDP cells as phagocytic cells that can participate and contribute to immunity to parasites. © 2016 John Wiley & Sons Ltd.

  7. Activity evaluation from different native or irradiated with {sup 60} Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis; Avaliacao da atividade de diferentes venenos de serpentes, nativos ou irradiados, com radiacao gama de {sup 60} Co, quanto ao poder inibitorio do crescimento de Leishmania (Leishmania) amazonensis

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    Lourenco, Cecilia de Oliveira

    2000-07-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK{sub 2} mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of {sup 60}Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  8. Physalis angulata induces death of promastigotes and amastigotes of Leishmania (Leishmania) amazonensis via the generation of reactive oxygen species.

    Science.gov (United States)

    Da Silva, B J M; Da Silva, R R P; Rodrigues, A P D; Farias, L H S; Do Nascimento, J L M; Silva, E O

    2016-03-01

    Leishmaniasis are a neglected group of emerging diseases that have been found in 98 countries and are caused by protozoa of the genus Leishmania. The therapy for leishmaniasis causes several side effects and leads to drug-resistant strains. Natural products from plants have exhibited activities against Leishmania in various experimental models. Physalis angulata is a widely used plant in popular medicine, and in the literature it has well-documented leishmanicidal activity. However, its mechanism of action is still unknown. Thus, this study aims to evaluate the mechanism driving the leishmanicidal activity of an aqueous extract of P. angulata root (AEPa). AEPa was effective against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. This effect was mediated by an increase of reactive oxygen species (ROS), but not of nitric oxide (NO). The increased production of ROS induces cell death by phenotypes seems by apoptosis cell death in Leishmania, but not autophagy or necrosis. In addition, morphological analysis of macrophages showed that AEPa induced a high number of cytoplasmic projections, increased the volume of cytoplasm and number of vacuoles, caused cytoskeleton alterations and resulted in high spreading ability. AEPa also promoted superoxide anion (O2(-)) production in both uninfected macrophages and those infected with Leishmania. Therefore, these results revealed that AEPa causes cell death by phenotypes seems by apoptosis cell death in L. amazonensis and modulates macrophage activation through morphofunctional alterations and O2(-) generation to induce Leishmania death. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Cytotoxicity and anti-Leishmania amazonensis activity of Citrus sinensis leaf extracts.

    Science.gov (United States)

    Garcia, Andreza R; Amaral, Ana Claudia F; Azevedo, Mariana M B; Corte-Real, Suzana; Lopes, Rosana C; Alviano, Celuta S; Pinheiro, Anderson S; Vermelho, Alane B; Rodrigues, Igor A

    2017-12-01

    Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease characterized by lesional polymorphism and the commitment of skin surface. Previous reports demonstrated that the Citrus genus possess antimicrobial activity. This study evaluated the anti-L. amazonensis activity of Citrus sinensis (L.) Osbeck (Rutaceae) extracts. Citrus sinensis dried leaves were subjected to maceration with hexane (CH), ethyl acetate (CEA), dichloromethane/ethanol (CD/Et - 1:1) or ethanol/water (CEt/W - 7:3). Leishmania amazonensis promastigotes were treated with C. sinensis extracts (1-525 μg/mL) for 120 h at 27 °C. Ultrastructure alterations of treated parasites were evaluated by transmission electron microscopy. Cytotoxicity of the extracts was assessed on RAW 264.7 and J774.G8 macrophages after 48-h treatment at 37 °C using the tetrazolium assay. In addition, Leishmania-infected macrophages were treated with CH and CD/Et (10-80 μg/mL). CH, CD/Et and CEA displayed antileishmanial activity with 50% inhibitory activity (IC 50 ) of 25.91 ± 4.87, 54.23 ± 3.78 and 62.74 ± 5.04 μg/mL, respectively. Parasites treated with CD/Et (131.2 μg/mL) presented severe alterations including mitochondrial swelling, lipid body formation and intense cytoplasmic vacuolization. CH and CD/Et demonstrated cytotoxic effects similar to that of amphotericin B in the anti-amastigote assays (SI of 2.16, 1.98 and 1.35, respectively). Triterpene amyrins were the main substances in CH and CD/Et extracts. In addition, 80 μg/mL of CD/Et reduced the number of intracellular amastigotes and the percentage of infected macrophages in 63% and 36%, respectively. The results presented here highlight C. sinensis as a promising source of antileishmanial agents.

  10. Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania) amazonensis in the state of Mato Grosso do Sul, mid-western Brazil.

    Science.gov (United States)

    Dorval, Maria Elizabeth Cavalheiros; Alves, Tulia Peixoto; Cristaldo, Geucira; Rocha, Hilda Carlos da; Alves, Murilo Andrade; Oshiro, Elisa Teruya; Oliveira, Alessandra Gutierrez de; Brazil, Reginaldo Peçanha; Galati, Eunice Aparecida Bianchi; Cunha, Rivaldo Venancio da

    2010-01-01

    The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

  11. Effects of medicinal plant extracts on growth of Leishmania (L. amazonensis and Trypanosoma cruzi Efeito de extratos de plantas medicinais no crescimento de Leishmania (L. amazonensis e Trypanosoma cruzi

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    Patrícia Shima Luize

    2005-03-01

    Full Text Available This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L. amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L. amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi.

  12. INTRACELLULAR Leishmania amazonensis KILLING INDUCED BY THE GUANINE NUCLEOSIDE 8-BROMOGUANOSINE

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    GIORGIO Selma

    1998-01-01

    Full Text Available In this study we investigated the effect of 8-Bromoguanosine, an immunostimulatory compound, on the cytotoxicity of macrophages against Leishmania amazonensis in an in vitro system. The results showed that macrophages treated with 8-Bromoguanosine before or after infection are capable to reduce parasite load, as monitored by the number of amastigotes per macrophage and the percentage of infected cells (i.e. phagocytic index. Since 8-Bromoguanosine was not directly toxic to the promastigotes, it was concluded that the ribonucleoside induced macrophage activation. Presumably, 8-Bromoguanosine primed macrophages by inducing interferon alpha and beta which ultimately led to L. amazonensis amastigote killing. The results suggest that guanine ribonucleosides may be useful to treat infections with intracellular pathogens.

  13. Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

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    Bonetti, Franco C.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Biologia Molecular]. E-mail: fbonetti@usp.br; Andrade Junior, Heitor Franco de [Instituto de Medicina Tropical de Sao Paulo, SP (Brazil). Lab. de Protozoologia

    2005-07-01

    Leishmania spp. causes a spectrum of human diseases, ranging from self-healing skin lesions to severe and lethal visceral disease. In previous work we demonstrated that the protein and nucleic acid metabolism and oxidative respiration were severely affected by irradiation, in a dose response way, but a small but representative fractions are relatively radio resistant, surviving after 800 Gy of {sup 60}Co irradiation. The best explanation could be a selection of metacyclic promastigotes. In these forms, the G0 state allows the adequate correction of DNA repair after the irradiation insult. In this work, we are looking for the ideal radiation dose to select the higher proportion of metacyclic forms of L.. (L.) amazonensis in culture. Parasites were grown in RPMI 1640 medium, plus 20% fetal calf serum, than they were irradiated with different doses ranging between 25 and 400 Gy. Parasites irradiated at 400 Gy infected, proportionally, more cells than parasites irradiated at other doses. To confirm this metacyclogenesis, a complement lysis assay was performed with 5, 10 and 20% of male guinea pig blood serum at 20 deg C for 3 hours, and parasites counted. Guinea pig serum a 10% promotes more lysis, with 200 Gy irradiated parasites being less affected, probably due to metacyclic selection. These preliminary results suggests that the ionizing radiation, specially between 200 and 400 Gy, could be a alternative tool for the selection of metacyclic forms of Leishmania amazonensis in culture. (a0011uth.

  14. Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

    International Nuclear Information System (INIS)

    Bonetti, Franco C.; Nascimento, Nanci do; Andrade Junior, Heitor Franco de

    2005-01-01

    Leishmania spp. causes a spectrum of human diseases, ranging from self-healing skin lesions to severe and lethal visceral disease. In previous work we demonstrated that the protein and nucleic acid metabolism and oxidative respiration were severely affected by irradiation, in a dose response way, but a small but representative fractions are relatively radio resistant, surviving after 800 Gy of 60 Co irradiation. The best explanation could be a selection of metacyclic promastigotes. In these forms, the G0 state allows the adequate correction of DNA repair after the irradiation insult. In this work, we are looking for the ideal radiation dose to select the higher proportion of metacyclic forms of L.. (L.) amazonensis in culture. Parasites were grown in RPMI 1640 medium, plus 20% fetal calf serum, than they were irradiated with different doses ranging between 25 and 400 Gy. Parasites irradiated at 400 Gy infected, proportionally, more cells than parasites irradiated at other doses. To confirm this metacyclogenesis, a complement lysis assay was performed with 5, 10 and 20% of male guinea pig blood serum at 20 deg C for 3 hours, and parasites counted. Guinea pig serum a 10% promotes more lysis, with 200 Gy irradiated parasites being less affected, probably due to metacyclic selection. These preliminary results suggests that the ionizing radiation, specially between 200 and 400 Gy, could be a alternative tool for the selection of metacyclic forms of Leishmania amazonensis in culture. (author)

  15. Cross-protective immunity to Leishmania amazonensis is mediated by CD4+ and CD8+-epitopes of Leishmania donovani Nucleoside Hydrolase terminal domains

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    Dirlei eNico

    2014-05-01

    Full Text Available The Nucleoside hydrolase of Leishmania donovani (NH36 is a phylogenetic marker of high homology among Leishmania parasites. In mice and dog vaccination NH36 induces a CD4+ T cell-driven protective response against Leishmania chagasi infection directed against its C-terminal domain (F3. The C-terminal and N-terminal domain vaccines also decreased the footpad lesion caused by Leishmania amazonensis. We studied the basis of the crossed immune response using recombinant generated peptides covering the whole NH36 sequence and saponin for mice prophylaxis against L. amazonensis. The F1 (amino acids 1-103 and F3 peptide (amino acids 199-314 vaccines enhanced the IgG and IgG2a anti-NH36 antibodies to similar levels. The F3 vaccine induced the strongest DTH response, the highest proportions of NH36-specific CD4+ and CD8+ T cells after challenge and the highest expression of IFN-γ and TNF-α. The F1 vaccine, on the other hand, induced a weaker but significant DTH response and a mild enhancement of IFN-γ and TNF-α levels. The in vivo depletion with anti-CD4 or CD8 monoclonal antibodies disclosed that cross-protection against L. amazonensis infection was mediated by a CD4+ T cell response directed against the C-terminal domain (75% of reduction of the size of footpad lesion followed by a CD8+ T cell response against the N-terminal domain of NH36 (57% of reduction of footpad lesions. Both vaccines were capable of inducing long-term cross-immunity. The amino acid sequence of NH36 showed 93% identity to the sequence of the NH A34480 of L. amazonensis which also showed the presence of completely conserved predicted epitopes for CD4+ and CD8+ T cells in F1 domain, and of CD4+ epitopes differing in a single amino acid, in F1 and F3 domains. The identification of the C-terminal and N-terminal domains as the targets of the immune response to NH36 in the model of L. amazonesis infection represents a basis for the rationale development of a bivalent vaccine

  16. Experimental Infection of Lutzomyia (Nyssomyia) whitmani (Diptera: Psychodidae: Phlebotominae) With Leishmania (Viannia) braziliensis and Leishmania (L.) amazonensis, Etiological Agents of American Tugumentary Leishmaniasis.

    Science.gov (United States)

    Fonteles, Raquel S; Pereira Filho, Adalberto A; Moraes, Jorge L P; Kuppinger, Oliver; Rebêlo, José M M

    2016-01-01

    Leishmania (L.) amazonensis (Lainson & Shaw, 1972) and Leishmania (Viannia) braziliensis (Vianna, 1911) are the principal causative agents of American tegumentary leishmaniasis (ATL) in Brazil. L. amazonensis also causes diffuse cutaneous leishmaniasis (DCL) vectored principally by Lutzomyia flaviscutellata and secondarily by Lutzomyia whitmani (Antunes & Coutinho, 1939). The latter is the most common phlebotomine in the state of Maranhão, and it is the focal species for potential ATL transmission. For this reason, we tested the ability of L. whitmani to become infected with Lutzomyia parasites. Phlebotomines were derived from a colony maintained in the laboratorial conditions. The first generation, uninfected females were offered a bloodmeal with mice infected with the strains of both parasites. We found that L. whitmani can become infected with both parasite species, with infection rates of 65.2% (L. braziliensis) and 47.4% (L. amazonensis). We conclude that in Maranhão, L. whitmani is likely an important vector in the transmission of ATL and may function as a vector of DCL. This possibility should be further investigated. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions

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    Debora B. Petropolis

    2014-04-01

    Full Text Available Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D environment mainly composed of Collagen I (COL I. This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited “freeze and run” migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular “home”—macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model.

  18. Activity evaluation from different native or irradiated with 60 Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis

    International Nuclear Information System (INIS)

    Lourenco, Cecilia de Oliveira

    2000-01-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK 2 mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of 60 Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  19. Leishmania amazonensis DNA in wild females of Lutzomyia cruzi (Diptera: Psychodidae) in the state of Mato Grosso do Sul, Brazil.

    Science.gov (United States)

    Oliveira, Everton Falcão de; Casaril, Aline Etelvina; Mateus, Nathália Lopes Fontoura; Murat, Paula Guerra; Fernandes, Wagner Souza; Oshiro, Elisa Teruya; Oliveira, Alessandra Gutierrez de; Galati, Eunice Aparecida Bianchi

    2015-12-01

    Studies on natural infection by Leishmania spp of sandflies collected in endemic and nonendemic areas can provide important information on the distribution and intensity of the transmission of these parasites. This study sought to investigate the natural infection by Leishmaniain wild female sandflies. The specimens were caught in the city of Corumbá, state of Mato Grosso do Sul (Brazil) between October 2012-March 2014, and dissected to investigate flagellates and/or submitted to molecular analysis to detect Leishmania DNA. A total of 1,164 females (77.56% of which were Lutzomyia cruzi) representing 11 species were investigated using molecular analysis; 126 specimens of Lu. cruziwere dissected and also submitted to molecular analysis. The infection rate based on the presence of Leishmania DNA considering all the sandfly species analysed was 0.69%; only Leishmania (Leishmania) amazonensis was identified in Lu. cruzi by the molecular analysis. The dissections were negative for flagellates. This is the first record of the presence of L. (L.) amazonensis DNA in Lu. cruzi, and the first record of this parasite in this area. These findings point to the need for further investigation into the possible role of this sandfly as vector of this parasite.

  20. HIV aspartyl peptidase inhibitors interfere with cellular proliferation, ultrastructure and macrophage infection of Leishmania amazonensis.

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    Lívia O Santos

    Full Text Available BACKGROUND: Leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. Current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the increase in the number of cases of Leishmania-HIV coinfection, due to the overlap between the AIDS epidemic and leishmaniasis. METHODOLOGY/PRINCIPAL FINDINGS: In the present report, we have investigated the effect of HIV aspartyl peptidase inhibitors (PIs on the Leishmania amazonensis proliferation, ultrastructure, interaction with macrophage cells and expression of classical peptidases which are directly involved in the Leishmania pathogenesis. All the HIV PIs impaired parasite growth in a dose-dependent fashion, especially nelfinavir and lopinavir. HIV PIs treatment caused profound changes in the leishmania ultrastructure as shown by transmission electron microscopy, including cytoplasm shrinking, increase in the number of lipid inclusions and some cells presenting the nucleus closely wrapped by endoplasmic reticulum resembling an autophagic process, as well as chromatin condensation which is suggestive of apoptotic death. The hydrolysis of HIV peptidase substrate by L. amazonensis extract was inhibited by pepstatin and HIV PIs, suggesting that an aspartyl peptidase may be the intracellular target of the inhibitors. The treatment with HIV PIs of either the promastigote forms preceding the interaction with macrophage cells or the amastigote forms inside macrophages drastically reduced the association indexes. Despite all these beneficial effects, the HIV PIs induced an increase in the expression of cysteine peptidase b (cpb and the metallopeptidase gp63, two well-known virulence factors expressed by Leishmania spp. CONCLUSIONS/SIGNIFICANCE: In the face of leishmaniasis/HIV overlap, it is critical to further comprehend the sophisticated interplays among Leishmania

  1. Technetium-99m labeling anti-amastigote polyclonal antibodies of Leishmania amazonensis

    International Nuclear Information System (INIS)

    Araujo, J.G.V.C.; Toledo, V.P.C.P.; Guimaraes, T.M.P.D.; Bernardo-Filho, M.; Simal, C.J.R.; Mota, L.G.; Diniz, S.O.F.; Cardoso, V.N.

    2002-01-01

    Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m ( 99m Tc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of 99m Tc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with 99m Tc did not modify the immunoreactivity of the antibody, since it was able to identify in vitro and in vivo the specific antigen of Leishmania amazonensis

  2. Benzaldehyde thiosemicarbazone derived from limonene complexed with copper induced mitochondrial dysfunction in Leishmania amazonensis.

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    Elizandra Aparecida Britta

    Full Text Available BACKGROUND: Leishmaniasis is a major health problem that affects more than 12 million people. Treatment presents several problems, including high toxicity and many adverse effects, leading to the discontinuation of treatment and emergence of resistant strains. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the in vitro antileishmanial activity of benzaldehyde thiosemicarbazone derived from limonene complexed with copper, termed BenzCo, against Leishmania amazonensis. BenzCo inhibited the growth of the promastigote and axenic amastigote forms, with IC(50 concentrations of 3.8 and 9.5 µM, respectively, with 72 h of incubation. Intracellular amastigotes were inhibited by the compound, with an IC(50 of 10.7 µM. BenzCo altered the shape, size, and ultrastructure of the parasites. Mitochondrial membrane depolarization was observed in protozoa treated with BenzCo but caused no alterations in the plasma membrane. Additionally, BenzCo induced lipoperoxidation and the production of mitochondrial superoxide anion radicals in promastigotes and axenic amastigotes of Leishmania amazonensis. CONCLUSION/SIGNIFICANCE: Our studies indicated that the antileishmania activity of BenzCo might be associated with mitochondrial dysfunction and oxidative damage, leading to parasite death.

  3. Eupomatenoid-5 Isolated from Leaves of Piper regnellii Induces Apoptosis in Leishmania amazonensis

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    Francielle Pelegrin Garcia

    2013-01-01

    Full Text Available Leishmania spp. are protozoa responsible for leishmaniasis, a neglected disease that kills up to 50,000 people every year. Current therapies mainly rely on antimonial drugs that are inadequate because of their poor efficacy and safety and increased drug resistance. An urgent need exists to find new and more affordable drugs. Our previous study demonstrated the antileishmanial activity of eupomatenoid-5, a neolignan obtained from leaves of Piper regnellii var. pallescens. The aim of the present study was to clarify the mode of action of eupomatenoid-5 against L. amazonensis. We used biochemical and morphological techniques and demonstrated that eupomatenoid-5 induced cell death in L. amazonensis promastigotes, sharing some phenotypic features observed in metazoan apoptosis, including increased reactive oxygen species production, hypopolarization of mitochondrial potential, phosphatidylserine exposure, decreased cell volume, and G0/G1 phase cell cycle arrest.

  4. Activity of the Lupane isolated from Combretum leprosum against Leishmania amazonensis promastigotes

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    Teles, Carolina B.G.; Silva-Jardim, Izaltina; Silva, Alexandre de A.E.; Zuliani, Juliana P.; Stabeli, Rodrigo G., E-mail: izaltina.jardim@pq.cnpq.b [Instituto de Pesquisas em Patologias Tropicais de Rondonia (IPEPATRO), Porto Velho, RO (Brazil); Moreira, Leandro S.; Facundo, Valdir A. [Universidade Federal de Rondonia, Porto Velho, RO (Brazil)

    2011-07-01

    This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3{beta}, 6{beta}, 16{beta}-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania Amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC{sub 50} was 24.8 {mu}g mL{sup -1}. However, the triterpene 3{beta}, 6{beta}, 16{beta}-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 {mu}g mL{sup -1}, showed a potent inhibitory activity on promastigotes proliferation (IC{sub 50} = 3.3 {mu}g mL{sup -1}). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC{sub 50} = 3.48 {mu}g mL{sup -1} and 5.8 {mu}g mL{sup -1}, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. Amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs. (author)

  5. Reprogramming neutral lipid metabolism in mouse dendritic leucocytes hosting live Leishmania amazonensis amastigotes.

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    Hervé Lecoeur

    Full Text Available BACKGROUND: After loading with live Leishmania (L amazonensis amastigotes, mouse myeloid dendritic leucocytes/DLs are known to undergo reprogramming of their immune functions. In the study reported here, we investigated whether the presence of live L. amazonensis amastigotes in mouse bone marrow-derived DLs is able to trigger re-programming of DL lipid, and particularly neutral lipid metabolism. METHODOLOGY/PRINCIPAL FINDINGS: Affymetrix-based transcriptional profiles were determined in C57BL/6 and DBA/2 mouse bone marrow-derived DLs that had been sorted from cultures exposed or not to live L. amazonensis amastigotes. This showed that live amastigote-hosting DLs exhibited a coordinated increase in: (i long-chain fatty acids (LCFA and cholesterol uptake/transport, (ii LCFA and cholesterol (re-esterification to triacyl-sn-glycerol (TAG and cholesteryl esters (CE, respectively. As these neutral lipids are known to make up the lipid body (LB core, oleic acid was added to DL cultures and LB accumulation was compared in live amastigote-hosting versus amastigote-free DLs by epi-fluorescence and transmission electron microscopy. This showed that LBs were both significantly larger and more numerous in live amastigote-hosting mouse dendritic leucocytes. Moreover, many of the larger LB showed intimate contact with the membrane of the parasitophorous vacuoles hosting the live L. amazonensis amastigotes. CONCLUSIONS/SIGNIFICANCE: As leucocyte LBs are known to be more than simple neutral lipid repositories, we set about addressing two related questions. Could LBs provide lipids to live amastigotes hosted within the DL parasitophorous vacuole and also deliver? Could LBs impact either directly or indirectly on the persistence of L. amazonensis amastigotes in rodent skin?

  6. [Molecular typing of Leishmania (Leishmania) amazonensis and species of the subgenus Viannia associated with cutaneous and mucosal leishmaniasis in Colombia: A concordance study].

    Science.gov (United States)

    Ovalle-Bracho, Clemencia; Camargo, Carolina; Díaz-Toro, Yira; Parra-Muñoz, Marcela

    2018-03-15

    Multilocus enzyme electrophoresis (MLEE) is the reference standard for the characterization of Leishmania species. The test is restricted to specialized laboratories due to its technical complexity, cost, and time required to obtain results. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is used to identify Leishmania species. To establish the concordance between the two tests as identifying methods for circulating species in Colombia. A total of 96 isolates from patients with cutaneous or mucosal leishmaniasis were selected and identified by MLEE and PCR-RFLP with miniexon and hsp70 as the molecular targets, which were used sequentially. Restriction enzymes HaeIII and BccI were similarly applied. Cohen's kappa coefficient and the 95% confidence interval (CI) were calculated. The kappa coefficient and the 95% CI between MLEE and PCR-RFLP displayed "very good" concordance with a coefficient of 0.98 (CI95%: 0.98 to 1.00). The identified species were Leishmania Viannia braziliensis, Leishmania Viannia panamensis, Leishmania Viannia guyanensis and Leishmania Leishmania amazonensis. A total of 80 of the 96 isolates were sequenced and the results obtained by PCR-RFLP were confirmed. Due to the concordance obtained between tests results with the amplification of the genes miniexon and hsp70, PCR-RFLP is proposed as an alternative for identifying circulating Leishmania species in Colombia.

  7. Insulin-Like Growth Factor-I Induces Arginase Activity in Leishmania amazonensis Amastigote-Infected Macrophages through a Cytokine-Independent Mechanism

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    Celia Maria Vieira Vendrame

    2014-01-01

    Full Text Available Leishmania (Leishmania amazonensis exhibits peculiarities in its interactions with hosts. Because amastigotes are the primary form associated with the progression of infection, we studied the effect of insulin-like growth factor (IGF-I on interactions between L. (L. amazonensis amastigotes and macrophages. Upon stimulation of infected macrophages with IGF-I, we observed decreased nitric oxide production but increased arginase expression and activity, which lead to increased parasitism. However, stimulation of amastigote-infected macrophages with IGF-I did not result in altered cytokine levels compared to unstimulated controls. Because IGF-I is present in tissue fluids and also within macrophages, we examined the possible effect of this factor on phosphatidylserine (PS exposure on amastigotes, seen previously in tissue-derived amastigotes leading to increased parasitism. Stimulation with IGF-I induced PS exposure on amastigotes but not on promastigotes. Using a PS-liposome instead of amastigotes, we observed that the PS-liposome but not the control phosphatidylcholine-liposome led to increased arginase activity in macrophages, and this process was not blocked by anti-TGF-β antibodies. Our results suggest that in L. (L. amazonensis amastigote-infected macrophages, IGF-I induces arginase activity directly in amastigotes and in macrophages through the induction of PS exposure on amastigotes in the latter, which could lead to the alternative activation of macrophages through cytokine-independent mechanisms.

  8. Photodynamic Vaccination of BALB/c Mice for Prophylaxis of Cutaneous Leishmaniasis Caused by Leishmania amazonensis

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    Sayonara M. Viana

    2018-02-01

    Full Text Available Background: Photosensitizers (PS, like porphyrins and phthalocyanines (PC are excitable by light to generate cytotoxic singlet oxygen and other reactive oxygen species in the presence of atmospheric O2. Photodynamic inactivation of Leishmania by this means renders them non-viable, but preserves their effective use as vaccines. Leishmania can be photo-inactivated after PS-sensitization by loading via their endocytic uptake of PC or endogenous induction of transgenic mutants with delta-aminolevulinate (ALA to accumulate cytosolic uroporphyrin I (URO. Here, PS-sensitization and photo-inactivation of Leishmaniaamazonensis was further examined in vitro and in vivo for vaccination against cutaneous leishmaniasis (CL.Methods and Results:Leishmania amazonensis promastigotes were photodynamically inactivated in vitro by PC-loading followed by exposure to red light (1–2 J/cm2 or ALA-induction of uroporphyrinogenic transfectants to accumulate cytosolic URO followed by longwave UV exposure. When applied individually, both strategies of photodynamic inactivation were found to significantly, albeit incompletely abolish the MTT reduction activities of the promastigotes, their uptake by mouse bone marrow-derived macrophages in vitro and their infectivity to mouse ear dermis in vivo. Inactivation of Leishmania to completion by using a combination of both strategies was thus used for the sake of safety as whole-cell vaccines for immunization of BALB/c mice. Different cutaneous sites were assessed for the efficacy of such photodynamic vaccination in vivo. Each site was inoculated first with in vitro doubly PS-sensitized promastigotes and then spot-illuminated with white light (50 J/cm2 for their photo-inactivation in situ. Only in ear dermis parasites were photo-inactivated beyond detection. Mice were thus immunized once in the ear and challenged 3 weeks later at the tail base with virulent L. amazonensis. Prophylaxis was noted in mice photodynamically

  9. Toll-like receptors 2, 4, and 9 expressions over the entire clinical and immunopathological spectrum of American cutaneous leishmaniasis due to Leishmania (V.) braziliensis and Leishmania (L.) amazonensis

    Science.gov (United States)

    Campos, Marliane Batista; Lima, Luciana Vieira do Rêgo; de Lima, Ana Carolina Stocco; Vasconcelos dos Santos, Thiago; Ramos, Patrícia Karla Santos; Gomes, Claudia Maria de Castro

    2018-01-01

    Leishmania (V.) braziliensis and Leishmania(L.) amazonensis are the most pathogenic agents of American Cutaneous Leishmaniasis in Brazil, causing a wide spectrum of clinical and immunopathological manifestations, including: localized cutaneous leishmaniasis (LCLDTH+/++), borderline disseminated cutaneous leishmaniasis (BDCLDTH±), anergic diffuse cutaneous leishmaniasis (ADCLDTH-), and mucosal leishmaniasis (MLDTH++++). It has recently been demonstrated, however, that while L. (V.) braziliensis shows a clear potential to advance the infection from central LCL (a moderate T-cell hypersensitivity form) towards ML (the highest T-cell hypersensitivity pole), L. (L.) amazonensis drives the infection in the opposite direction to ADCL (the lowest T-cell hypersensitivity pole). This study evaluated by immunohistochemistry the expression of Toll-like receptors (TLRs) 2, 4, and 9 and their relationships with CD4 and CD8 T-cells, and TNF-α, IL-10, and TGF-β cytokines in that disease spectrum. Biopsies of skin and mucosal lesions from 43 patients were examined: 6 cases of ADCL, 5 of BDCL, and 11 of LCL caused byL. (L.) amazonensis; as well as 10 cases of LCL, 4 of BDCL, and 6 of ML caused byL. (V.) braziliensis. CD4+ T-cells demonstrated their highest expression in ML and, in contrast, their lowest in ADCL. CD8+ T-cells also showed their lowest expression in ADCL as compared to the other forms of the disease. TNF-α+showed increased expression from ADCL to ML, while IL-10+and TGF-β+ showed increased expression in the opposite direction, from ML to ADCL. With regards to TLR2, 4, and 9 expressions, strong interactions of TLR2 and 4 with clinical forms associated with L. (V.) braziliensis were observed, while TLR9, in contrast, showed a strong interaction with clinical forms linked to L. (L.) amazonensis. These findings strongly suggest the ability of L. (V.) braziliensis and L. (L.) amazonensis to interact with those TLRs to promote a dichotomous T-cell immune response in ACL

  10. Exploring the Association of Surface Plasmon Resonance with Recombinant MHC:Ig Hybrid Protein as a Tool for Detecting T Lymphocytes in Mice Infected with Leishmania (Leishmania amazonensis

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    Lenilton Silva da Silveira-Júnior

    2017-01-01

    Full Text Available A surface plasmon resonance- (SPR- based recognition method applying H-2 Ld:Ig/peptides complexes for ex vivo monitoring cellular immune responses during murine infection with Leishmania (Leishmania amazonensis is described. Lymphocytes from lesion-draining popliteal lymph nodes were captured on a carboxylated sensor chip surface previously functionalized with H-2 Ld:Ig (DimerX protein bound to synthetic peptides derived from the COOH-terminal region of cysteine proteinase B of L. (L. amazonensis. In computational analysis, these peptides presented values of kinetic constants favorable to form complexes with H-2 Ld at neutral pH, with a Gibbs free energy ΔG°<0. The assayed DimerX:peptide complexes presented the property of attaching to distinct T lymphocytes subsets, obtained from experimentally infected BALB/c mice, in each week of infection, thus indicating a temporal variation in specific T lymphocytes populations, each directed to a different COOH-terminal region-derived peptide. The experimental design proposed herein is an innovative approach for cellular immunology studies of a neglected disease, providing a useful tool for the analysis of specific T lymphocytes subsets.

  11. Isolation of an enriched plasma membrame subpellicular microtubule fraction of Leishmania mexicana amazonensis

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    Solange L. Timm

    1980-01-01

    Full Text Available A cell fractionation procedure previously developed for Trypanosoma cruzi was applied to isolated the plasma membrane of promastigotes of Leishania mexicana amazonensis. The cell, swollen in an hypotonic mediun, were disrupted in the presence of a nonionic detergent and the membrane fraction isolated by differencial centrifugation. Electron microscopy showed that the fraction consisted of pieces of the plasma membrane associated with subpellicular microtubules. It was also shown that this fraction is able to induce cell-mediated immune response in mice.Um método de fracionamento subcelular, previamente desenvolvido para Trypanosoma cruzi, foi aplicado para isolar a membrana plasmática de promastigotas de Leishmania mexicana amazonensis. As células, após turgimento em meio hipotônico, foram rompidas na presença de um detergente não iônico e a fração de membrana isolada por centrifugação diferencial. A microscopia eletrônica mostrou consistir a fração de fragmentos de membrana plasmática associados com microtúbulos subpeliculares. Foi também mostrado que esta fração era capaz de induzir resposta celular em camundongos.

  12. Subversion of Immunity by Leishmania amazonensis Parasites: Possible Role of Phosphatidylserine as a Main Regulator

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    Joao Luiz Mendes Wanderley

    2012-01-01

    Full Text Available Leishmania amazonensis parasites cause progressive disease in most inbred mouse strains and are associated with the development of diffuse cutaneous leishmaniasis in humans. The poor activation of an effective cellular response is correlated with the ability of these parasites to infect mononuclear phagocytic cells without triggering their activation or actively suppressing innate responses of these cells. Here we discuss the possible role of phosphatidylserine exposure by these parasites as a main regulator of the mechanism underlying subversion of the immune system at different steps during the infection.

  13. DNA sequencing confirms the involvement of Leishmania (L. amazonensis in american tegumentary leishmaniasis in the state of São Paulo, Brazil

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    Angela Rapela Medeiros

    2008-01-01

    Full Text Available INTRODUCTION: American tegumentary leishmaniasis (ATL represents one of the most important public health issues in the world. An increased number of autochthonous cases of ATL in the Northeastern region of São Paulo State has been documented in the last few years, leading to a desire to determine the Leishmania species implicated. METHODS: PCR followed by DNA sequencing was carried out to identify a 120bp fragment from the universal kDNA minicircle of the genus Leishmania in 61 skin or mucosal biopsies from patients with ATL. RESULTS: DNA sequencing permitted the identification of a particular 15bp fragment (5' …GTC TTT GGG GCA AGT... 3' in all samples. Analysis by the neighbor-joining method showed the occurrence of two distinct groups related to the genus Viannia (V and Leishmania (L, each with two subgroups. Autochthonous cases with identity to a special Leishmania sequence not referenced in Genbank predominated in subgroup V.1, suggesting the possible existence of a subtype or mutation of Leishmania Viannia in this region. In the subgroup L.2, which showed identity with a known sequence of L. (L. amazonensis, there was a balanced distribution of autochthonous and non-autochthonous cases, including the mucosal and mucocutaneus forms in four patients. The last observation may direct us to new concepts, since the mucosal compromising has commonly been attributed to L. (V. braziliensis, even though L. (L. amazonensis is more frequent in the Amazonian region. CONCLUSIONS: These results confirm the pattern of distribution and possible mutations of these species, as well as the change in the clinical form presentation of ATL in the São Paulo State.

  14. Study of ionizing radiation as a tool for select promastigotes forms of Leishmania Amazonensis, and the megalomaniac response in experimental models; Estudo do uso da radiacao ionizante como ferramenta de selecao de formas promastigotas metaciclicas de Leishmania amazonensis, e a inducao de resposta imunologica em modelos experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Franco Claudio

    2006-07-01

    Actually, millions of people around the globe are under the risk of infection by a protozoan transmitted by a bit of a sand fly. This parasite is a Leishmania spp. This causes a wide spectrum disease, since a cutaneous disease to a visceral one. The cutaneous form is the major clinical manifestation (above 90%). The ionizing radiation, produced in a {sup 60}Co font, had being successes used to promote physical-chemical transformations on different protozoan, including Leishmania spp. In previous work was determined that promastigotes forms of Leishmania amazonensis, irradiated with different doses of radiation, lost their viability maintaining, however, their immunogenicity. In this work, was studied the use of ionizing radiation as a tool for selection of meta cyclic forms of the parasite in axenic culture, for a possible efficient irradiated immuno gene production. Our results shown that cultures irradiated with 400 Gy of gamma irradiation, has 75% of metacyclic form, which are capable to produce, in vitro, an infection that is similar the natural occurrence. These irradiated parasites have their internal cellular structure modified, maintaining their external structure intact. Susceptible strain of mice immunized with leishmania irradiated with different doses had high immunoglobulin production, and maintained this production after the challenge with naive parasites. In other strains this default was similar, however in lower titles. Immunodeficient mice didn't produce immunoglobulin nor on the immunization or on the challenge. (author)

  15. Study of ionizing radiation as a tool for select promastigotes forms of Leishmania Amazonensis, and the megalomaniac response in experimental models; Estudo do uso da radiacao ionizante como ferramenta de selecao de formas promastigotas metaciclicas de Leishmania amazonensis, e a inducao de resposta imunologica em modelos experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Franco Claudio

    2006-07-01

    Actually, millions of people around the globe are under the risk of infection by a protozoan transmitted by a bit of a sand fly. This parasite is a Leishmania spp. This causes a wide spectrum disease, since a cutaneous disease to a visceral one. The cutaneous form is the major clinical manifestation (above 90%). The ionizing radiation, produced in a {sup 60}Co font, had being successes used to promote physical-chemical transformations on different protozoan, including Leishmania spp. In previous work was determined that promastigotes forms of Leishmania amazonensis, irradiated with different doses of radiation, lost their viability maintaining, however, their immunogenicity. In this work, was studied the use of ionizing radiation as a tool for selection of meta cyclic forms of the parasite in axenic culture, for a possible efficient irradiated immuno gene production. Our results shown that cultures irradiated with 400 Gy of gamma irradiation, has 75% of metacyclic form, which are capable to produce, in vitro, an infection that is similar the natural occurrence. These irradiated parasites have their internal cellular structure modified, maintaining their external structure intact. Susceptible strain of mice immunized with leishmania irradiated with different doses had high immunoglobulin production, and maintained this production after the challenge with naive parasites. In other strains this default was similar, however in lower titles. Immunodeficient mice didn't produce immunoglobulin nor on the immunization or on the challenge. (author)

  16. Detection of Leishmania amazonensis and Leishmania braziliensis in Culicoides (Diptera, Ceratopogonidae) in an endemic area of cutaneous leishmaniasis in the Brazilian Amazonia.

    Science.gov (United States)

    Rebêlo, José Manuel Macário; Rodrigues, Bruno Leite; Bandeira, Maria da Conceição Abreu; Moraes, Jorge Luiz Pinto; Fonteles, Raquel Silva; Pereira, Silma Regina Ferreira

    2016-12-01

    Biting midges in the genus Culicoides act as vectors of arboviruses throughout the world and as vectors of filariasis in Latin America, the Caribbean, and parts of Africa. Although Culicoides spp. are currently not considered to be vectors of Leishmania protozoa, the high abundance of biting midges in areas with active cutaneous leishmaniasis transmission points to the possibility of Culicoides infection by these pathogens. We used PCR to test captured Culicoides species for natural infection with Leishmania spp. We tested 450 Culicoides females, divided into 30 pools of 15 individuals each, as follows: nine pools of C. foxi (135 specimens), seven pools of C. filariferus (105), seven pools of C. insignis (105), five pools of C. ignacioi (75), and two pools of C. flavivenula (30). PCR confirmed the presence of Leishmania braziliensis DNA in C. ignacioi (0.14%), C. insignis (0.14%), and C. foxi (0.11); and Le. amazonensis DNA in C. filariferus (0.14%) and C. flavivenula (0.50%). We conclude that these Culicoides species can be naturally infected, but vector competence and transmission capability must be confirmed in future studies. Our results warrant further investigation into the role of these biting midge species in the leishmaniasis epidemiological cycle. © 2016 The Society for Vector Ecology.

  17. Impacto de Leishmania amazonensis y la Sangre de Ave en el Potencial Biológico y Fecundidad de Lutzomyia migonei y Lutzomyia ovallesi (Diptera: Psychodidae

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    Elsa Nieves

    2011-03-01

    Resumo. Nos flebotomíneos (Diptera: Psychodidae o hábito pela hematofagia é responsável pela indução de vários processos fisiológicos também na transmissão de Leishmania Ross. O presente estudo compara o sangue de ave, de mamífero e com infecção por Leishmania amazonensis Lainson & Shaw sobre o potencial biológico de Lutzomyia migonei (França e de Lutzomyia ovallesi Ortiz. Foram utilizadas fêmeas das duas espécies alimentadas artificialmente com sangue de hamster (Mesocricetus auratus Waterhouse e frango (Gallus gallus Linnaeus, infectados com L. amazonensis. Os grupos controle foram alimentados somente com sangue, sem parasitas. Foram determinados o grau de repasto sanguíneo, o tempo de digestão, o padrão de diurese, o tempo de oviposição, a sobrevivencia a oviposição e a fecundidade. A espécie L. migonei quando alimentada com sangue de hamster e frango apresentaram maior fecundidade do que as fêmeas de L. ovallesi, a maior fecundidade foi com sangue de frango. A presença de Leishmania no sangue de frango ou sangue de hamster diminuiu significativamente o seu consumo, o que resultou na diminuição da sobrevida das fêmeas após a oviposição em L. migonei alimentados com sangue de frango e não com sangue de hamsters. Entretanto, não afetar a quantidade de sangue e a sobrevivência de oviposição de L. ovallesi. A infecção com L. amazonensis causo um aumento no número de ovos retidos e diminuiu o número de ovos postos por L. migonei e L. ovallesi, especialmente com sangue de frango e também reduz o tempo de digestão do sangue em ambas as espécies com sangue de frango, mas não com sangue de hamster. Embora o sangue de frango foi menos eficaz do que o sangue de hamster sobre o potencial biológico de L. migonei e L. ovallesi, não exclui o sangue de frango como uma fonte de sangue para a manutenção das populações de ambas as espécies nas casas.

  18. Transcriptional signatures of BALB/c mouse macrophages housing multiplying Leishmania amazonensis amastigotes

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    Lang Thierry

    2009-03-01

    Full Text Available Abstract Background Mammal macrophages (MΦ display a wide range of functions which contribute to surveying and maintaining tissue integrity. One such function is phagocytosis, a process known to be subverted by parasites like Leishmania (L. Indeed, the intracellular development of L. amazonensis amastigote relies on the biogenesis and dynamic remodelling of a phagolysosome, termed the parasitophorous vacuole, primarily within dermal MΦ. Results Using BALB/c mouse bone marrow-derived MΦ loaded or not with amastigotes, we analyzed the transcriptional signatures of MΦ 24 h later, when the amastigote population was growing. Total RNA from MΦ cultures were processed and hybridized onto Affymetrix Mouse430_2 GeneChips®, and some transcripts were also analyzed by Real-Time quantitative PCR (RTQPCR. A total of 1,248 probe-sets showed significant differential expression. Comparable fold-change values were obtained between the Affymetrix technology and the RTQPCR method. Ingenuity Pathway Analysis software® pinpointed the up-regulation of the sterol biosynthesis pathway (p-value = 1.31e-02 involving several genes (1.95 to 4.30 fold change values, and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signalling. Conclusion Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MΦ lipid and polyamine pathways. Moreover, these MΦ hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

  19. Glycosphingolipid antigens from Leishmania (L. amazonensis amastigotes: Binding of anti-glycosphingolipid monoclonal antibodies in vitro and in vivo

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    A.H. Straus

    1997-03-01

    Full Text Available Specific glycosphingolipid antigens of Leishmania (L. amazonensis amastigotes reactive with the monoclonal antibodies (MoAbs ST-3, ST-4 and ST-5 were isolated, and their structure was partially elucidated by negative ion fast atom bombardment mass spectrometry. The glycan moieties of five antigens presented linear sequences of hexoses and N-acetylhexosamines ranging from four to six sugar residues, and the ceramide moieties were found to be composed by a sphingosine d18:1 and fatty acids 24:1 or 16:0. Affinities of the three monoclonal antibodies to amastigote glycosphingolipid antigens were also analyzed by ELISA. MoAb ST-3 reacted equally well with all glycosphingolipid antigens tested, whereas ST-4 and ST-5 presented higher affinities to glycosphingolipids with longer carbohydrate chains, with five or more sugar units (slow migrating bands on HPTLC. Macrophages isolated from footpad lesions of BALB/c mice infected with Leishmania (L. amazonensis were incubated with MoAb ST-3 and, by indirect immunofluorescence, labeling was only detected on the parasite, whereas no fluorescence was observed on the surface of the infected macrophages, indicating that these glycosphingolipid antigens are not acquired from the host cell but synthesized by the amastigote. Intravenous administration of 125I-labeled ST-3 antibody to infected BALB/c mice showed that MoAb ST-3 accumulated significantly in the footpad lesions in comparison to blood and other tissues

  20. The Leishmania HSP20 Is Antigenic during Natural Infections, but, as DNA Vaccine, It does not Protect BALB/c Mice against Experimental L. amazonensis Infection

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    Ana M. Montalvo-Álvarez

    2008-01-01

    Full Text Available Protozoa of the genus Leishmania are causative agents of leishmaniasis, an important health problem in both human and veterinary medicine. Here, we describe a new heat shock protein (HSP in Leishmania, belonging to the small HSP (sHSP family in kinetoplastids. The protein is highly conserved in different Leishmania species, showing instead significant divergence with sHSP's from other organisms. The humoral response elicited against this protein during Leishmania infection has been investigated in natural infected humans and dogs, and in experimentally infected hamsters. Leishmania HSP20 is a prominent antigen for canine hosts; on the contrary, the protein seems to be a poor antigen for human immune system. Time-course analysis of appearance of anti-HSP20 antibodies in golden hamsters indicated that these antibodies are produced at late stages of the infection, when clinical symptoms of disease are patent. Finally, the protective efficacy of HSP20 was assessed in mice using a DNA vaccine approach prior to challenge with Leishmania amazonensis.

  1. Mitochondria Superoxide Anion Production Contributes to Geranylgeraniol-Induced Death in Leishmania amazonensis

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    Milene Valéria Lopes

    2012-01-01

    Full Text Available Here we demonstrate the activity of geranylgeraniol, the major bioactive constituent from seeds of Bixa orellana, against Leishmania amazonensis. Geranylgeraniol was identified through 1H and 13C nuclear magnetic resonance imaging and DEPT. The compound inhibited the promastigote and intracellular amastigote forms, with IC50 of 11±1.0 and 17.5±0.7 μg/mL, respectively. This compound was also more toxic to parasites than to macrophages and did not cause lysis in human blood cells. Morphological and ultrastructural changes induced by geranylgeraniol were observed in the protozoan by electronic microscopy and included mainly mitochondria alterations and an abnormal chromatin condensation in the nucleus. These alterations were confirmed by Rh 123 and TUNEL assays. Additionally, geranylgeraniol induces an increase in superoxide anion production. Collectively, our in vitro studies indicate geranylgeraniol as a selective antileishmanial that appears to be mediated by apoptosis-like cell death.

  2. Ecological Niche Modelling Predicts Southward Expansion of Lutzomyia (Nyssomyia flaviscutellata (Diptera: Psychodidae: Phlebotominae, Vector of Leishmania (Leishmania amazonensis in South America, under Climate Change.

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    Bruno M Carvalho

    Full Text Available Vector borne diseases are susceptible to climate change because distributions and densities of many vectors are climate driven. The Amazon region is endemic for cutaneous leishmaniasis and is predicted to be severely impacted by climate change. Recent records suggest that the distributions of Lutzomyia (Nyssomyia flaviscutellata and the parasite it transmits, Leishmania (Leishmania amazonensis, are expanding southward, possibly due to climate change, and sometimes associated with new human infection cases. We define the vector's climatic niche and explore future projections under climate change scenarios. Vector occurrence records were compiled from the literature, museum collections and Brazilian Health Departments. Six bioclimatic variables were used as predictors in six ecological niche model algorithms (BIOCLIM, DOMAIN, MaxEnt, GARP, logistic regression and Random Forest. Projections for 2050 used 17 general circulation models in two greenhouse gas representative concentration pathways: "stabilization" and "high increase". Ensemble models and consensus maps were produced by overlapping binary predictions. Final model outputs showed good performance and significance. The use of species absence data substantially improved model performance. Currently, L. flaviscutellata is widely distributed in the Amazon region, with records in the Atlantic Forest and savannah regions of Central Brazil. Future projections indicate expansion of the climatically suitable area for the vector in both scenarios, towards higher latitudes and elevations. L. flaviscutellata is likely to find increasingly suitable conditions for its expansion into areas where human population size and density are much larger than they are in its current locations. If environmental conditions change as predicted, the range of the vector is likely to expand to southeastern and central-southern Brazil, eastern Paraguay and further into the Amazonian areas of Bolivia, Peru, Ecuador

  3. Ecological Niche Modelling Predicts Southward Expansion of Lutzomyia (Nyssomyia) flaviscutellata (Diptera: Psychodidae: Phlebotominae), Vector of Leishmania (Leishmania) amazonensis in South America, under Climate Change.

    Science.gov (United States)

    Carvalho, Bruno M; Rangel, Elizabeth F; Ready, Paul D; Vale, Mariana M

    2015-01-01

    Vector borne diseases are susceptible to climate change because distributions and densities of many vectors are climate driven. The Amazon region is endemic for cutaneous leishmaniasis and is predicted to be severely impacted by climate change. Recent records suggest that the distributions of Lutzomyia (Nyssomyia) flaviscutellata and the parasite it transmits, Leishmania (Leishmania) amazonensis, are expanding southward, possibly due to climate change, and sometimes associated with new human infection cases. We define the vector's climatic niche and explore future projections under climate change scenarios. Vector occurrence records were compiled from the literature, museum collections and Brazilian Health Departments. Six bioclimatic variables were used as predictors in six ecological niche model algorithms (BIOCLIM, DOMAIN, MaxEnt, GARP, logistic regression and Random Forest). Projections for 2050 used 17 general circulation models in two greenhouse gas representative concentration pathways: "stabilization" and "high increase". Ensemble models and consensus maps were produced by overlapping binary predictions. Final model outputs showed good performance and significance. The use of species absence data substantially improved model performance. Currently, L. flaviscutellata is widely distributed in the Amazon region, with records in the Atlantic Forest and savannah regions of Central Brazil. Future projections indicate expansion of the climatically suitable area for the vector in both scenarios, towards higher latitudes and elevations. L. flaviscutellata is likely to find increasingly suitable conditions for its expansion into areas where human population size and density are much larger than they are in its current locations. If environmental conditions change as predicted, the range of the vector is likely to expand to southeastern and central-southern Brazil, eastern Paraguay and further into the Amazonian areas of Bolivia, Peru, Ecuador, Colombia and Venezuela

  4. Phloroglucinol derivatives from Hypericum species trigger mitochondrial dysfunction in Leishmania amazonensis.

    Science.gov (United States)

    Dagnino, Ana Paula Aquistapase; Mesquita, Camila Saporiti; Dorneles, Gilson Pires; Teixeira, Vivian de Oliveira Nunes; de Barros, Francisco Maikon Corrêa; Vidal Ccana-Ccapatinta, Gari; Fonseca, Simone Gonçalves; Monteiro, Marta Chagas; Júnior, Luiz Carlos Rodrigues; Peres, Alessandra; von Poser, Gilsane Lino; Romão, Pedro Roosevelt Torres

    2018-02-27

    Bioactive molecules isolated from plants are promising sources for the development of new therapies against leishmaniasis. We investigated the leishmanicidal activity of cariphenone A (1), isouliginosin B (2) and uliginosin B (3) isolated from Hypericum species. Promastigotes and amastigotes of Leishmania amazonensis were incubated with compounds 1-3 at concentrations 1-100 µ m for 48 h. The anti-promastigote effect of compounds was also tested in combinations. The cytotoxicity against macrophages and human erythrocytes were determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method and hemolysis assay, respectively. The compounds 1-3 showed high leishmanicidal activity against promastigotes, IC50 values of 10.5, 17.5 and 11.3 µ m, respectively. Synergistic interactions were found to the associations of compounds 1 and 2 [Σ fractional inhibitory concentration (FIC) = 0.41], and 2 and 3 (ΣFIC = 0.28) on promastigotes. All Hypericum compounds induced mitochondrial hyperpolarization and reactive oxygen species production in promastigotes. The compounds showed low cytotoxicity toward mammalian cells, high selectivity index and killed intracellular amastigotes probably mediated by oxidative stress. These results indicate that these compounds are promising candidates for the development of drugs against leishmaniasis.

  5. Leishmaniose cutânea na Amazônia: registro do primeiro caso humano de infecção mista, determinado por duas espécies distintas de Leishmnias: Leishmania brasiliensis e Leishmania mexicana amazonensis

    Directory of Open Access Journals (Sweden)

    F. T. Silveira

    1984-10-01

    Full Text Available Fez-se o registro, na Amazônia, do primeiro caso humano de infecção cutânea mista determinada por duas espécies distintas de Leishmania: a Leishmania braziliensis braziliensis e a Leishmania mexicana amazonensis. As duas amostras, em questão, foram isoladas de lesões distintas de um mesmo paciente, e a caracterização das espécies foi feita com base em observações de infecção experimental em hamsters, comportamento em meios artificiais de cultura, desenvolvimento de infecção experimental em Lutzomyia longipalpis, e eletroforese de isoenzimas em gel de amido. Conclui-se ser de interesse o achado que, combinado com o fato já conhecido de ausência de imunidade cruzada entre a maioria das leishmânias, sugere a necessidade do emprego de uma vacina polivalente para a região.

  6. Infective stages of Leishmania in the sandfly vector and some observations on the mechanism of transmission Formas infectante de Leishmania no vetor flebotomíneo e algumas observações sobre o mecanismo de transmissão

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    Ralph Lainson

    1987-09-01

    Full Text Available Infective stages of Leishmania (Leishmania amazonensis, capable of producing amastigote infections in hamster skin, were shown to be present in the experimentally infected sandfly vector Lutzomyia flaviscutellata 15, 25, 40, 49, 70, 96 and 120 hours after the flies had received their infective blood-meal. Similarly, infective stages of Leishmania (L. chagasi were demonstrated in the experimentally infected vector Lu. longipalpis examined 38, 50, 63, 87, 110, 135, 171 and 221 hours following the infective blood-meal, by the intraperitoneal inoculation of the flagellates into hamsters. The question of whether or not transmission by the bite of the sandfly is dependent on the presence of [quot ]metacyclic[quot ] promastigotes in the mouthparts of the vector is discussed.Foi demonstrado através de infecção experimental, que estágios infectivos de Leishmania (L. amazonensis, capazes de produzir infecção na pele do hamster, encontram-se presentes no vetor flebotomíneo Lutzomyia flaviscutellata 15, 25, 40, 49, 70, 96 e 120 horas após o inseto ter recebido sua refeição sangüínea infectiva. Da mesma maneira, foi comprovada a presença de estágios infectivos de L. (L. chagasi em exemplares do vetor Lu. longipalpis, examinados 38, 50, 63, 87, 110, 135, 171 e 221 horas após o repasto sangüíneo infectivo - através da inoculação em hamster por via intraperitoneal dos flagelados obtidos desses fle botomíneos. A questão sobre a transmissão do gênero Leishmania pelo flebotomíneo ser ou não dependente da presença de promastigotos "metacíclios" na proboscis do vetor, é discutida.

  7. Differential Recruitment of Dendritic Cells Subsets to Lymph Nodes Correlates with a Protective or Permissive T-Cell Response during Leishmania (Viannia) Braziliensis or Leishmania (Leishmania) Amazonensis Infection.

    Science.gov (United States)

    Carvalho, A K; Carvalho, K; Passero, L F D; Sousa, M G T; da Matta, V L R; Gomes, C M C; Corbett, C E P; Kallas, G E; Silveira, F T; Laurenti, M D

    2016-01-01

    Leishmania (L.) amazonensis (La) and L. (V.) braziliensis (Lb) are responsible for a large clinical and immunopathological spectrum in human disease; while La may be responsible for anergic disease, Lb infection leads to cellular hypersensitivity. To better understand the dichotomy in the immune response caused by these Leishmania species, we evaluated subsets of dendritic cells (DCs) and T lymphocyte in draining lymph nodes during the course of La and Lb infection in BALB/c mice. Our results demonstrated a high involvement of DCs in La infection, which was characterized by the greater accumulation of Langerhans cells (LCs); conversely, Lb infection led to an increase in dermal DCs (dDCs) throughout the infection. Considering the T lymphocyte response, an increase of effector, activated, and memory CD4(+) T-cells was observed in Lb infection. Interleukin- (IL-) 4- and IL-10-producing CD4(+)and CD8(+) T-cells were present in both La and Lb infection; however, interferon- (IFN-) γ-producing CD4(+)and CD8(+) T-cells were detected only in Lb infection. The results suggest that during Lb infection, the dDCs were the predominant subset of DCs that in turn was associated with the development of Th1 immune response; in contrast La infection was associated with a preferential accumulation of LCs and total blockage of the development of Th1 immune response.

  8. Exploring the unbinding of Leishmania (L.) amazonensis CPB derived-epitopes from H2 MHC class I proteins.

    Science.gov (United States)

    Brandt, Artur M L; Batista, Paulo Ricardo; Souza-Silva, Franklin; Alves, Carlos Roberto; Caffarena, Ernesto Raul

    2016-04-01

    New strategies to control Leishmania disease demand an extensive knowledge about several aspects of infection including the understanding of its molecular events. In murine models, cysteine proteinase B from Leishmania amazonensis promotes regulation of immune response, and fragments from its C-terminus extension (cyspep) can play a decisive role in the host-parasite interaction. The interaction between cyspep-derived peptides and major histocompatibility complex (MHC) proteins is a crucial factor in Leishmania infections. Seven cyspep-derived peptides, previously identified as capable of interacting with H-2 (murine) MHC class I proteins, were studied in this work. We established a protocol to simulate the unbinding of these peptides from the cleft of H-2 receptors. From the simulations, we estimated the corresponding free energy of dissociation (ΔGd ) and described the molecular events that occur during the exit of peptides from the cleft. To test the reliability of this method, we first applied it to a calibration set of four crystallographic MHC/peptide complexes. Next, we explored the unbinding of the seven complexes mentioned above. Results were consistent with ΔGd values obtained from surface plasmon resonance (SPR) experiments. We also identified some of the primary interactions between peptides and H-2 receptors, and we detected three regions of influence for the interaction. This pattern was systematically observed for the peptides and helped determine a minimum distance for the real interaction between peptides and H-2 proteins occurring at ∼ 25 Å. © 2016 Wiley Periodicals, Inc.

  9. Kinetoplastid membrane protein-11 is present in promastigotes and amastigotes of Leishmania amazonensis and its surface expression increases during metacyclogenesis

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    Denise CS Matos

    2010-05-01

    Full Text Available Kinetoplastid membrane protein-11 (KMP-11, a protein present in all kinetoplastid protozoa, is considered a potential candidate for a leishmaniasis vaccine. A suitable leishmaniasis vaccine candidate molecule must be expressed in amastigotes, the infective stage for mammals. However, the expression of KMP-11 in Leishmania amastigotes has been a subject of controversy. We evaluated the expression of this molecule in logarithmic and stationary growth phase promastigotes, as well as in amastigotes, of Leishmania amazonensis by immunoblotting, flow cytometry and immunocytochemistry, using a monoclonal antibody against KMP-11. We found that KMP-11 is present in promastigotes and amastigotes. In both stages, the protein was found in association with membrane structures (at the cell surface, flagellar pocket and intracellular vesicles. More importantly, its surface expression is higher in amastigotes than in promastigotes and increases during metacyclogenesis. The increased expression of KMP-11 in metacyclic promastigotes, and especially in amastigotes, indicates a role for this molecule in the parasite relationship with the mammalian host. The presence of this molecule in amastigotes is consistent with the previously demonstrated immunoprotective capacity of vaccine prototypes based on the KMP-11-coding gene and the presence of humoral and cellular immune responses to KMP-11 in Leishmania-infected humans and animals.

  10. The diverse and dynamic nature of Leishmania parasitophorous vacuoles studied by multidimensional imaging.

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    Fernando Real

    Full Text Available An important area in the cell biology of intracellular parasitism is the customization of parasitophorous vacuoles (PVs by prokaryotic or eukaryotic intracellular microorganisms. We were curious to compare PV biogenesis in primary mouse bone marrow-derived macrophages exposed to carefully prepared amastigotes of either Leishmania major or L. amazonensis. While tight-fitting PVs are housing one or two L. major amastigotes, giant PVs are housing many L. amazonensis amastigotes. In this study, using multidimensional imaging of live cells, we compare and characterize the PV biogenesis/remodeling of macrophages i hosting amastigotes of either L. major or L. amazonensis and ii loaded with Lysotracker, a lysosomotropic fluorescent probe. Three dynamic features of Leishmania amastigote-hosting PVs are documented: they range from i entry of Lysotracker transients within tight-fitting, fission-prone L. major amastigote-housing PVs; ii the decrease in the number of macrophage acidic vesicles during the L. major PV fission or L. amazonensis PV enlargement; to iii the L. amazonensis PV remodeling after homotypic fusion. The high content information of multidimensional images allowed the updating of our understanding of the Leishmania species-specific differences in PV biogenesis/remodeling and could be useful for the study of other intracellular microorganisms.

  11. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae: Aspects of the ecology of parasite-vector interactions.

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    Everton Falcão de Oliveira

    2017-02-01

    Full Text Available Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial

  12. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions.

    Science.gov (United States)

    Falcão de Oliveira, Everton; Oshiro, Elisa Teruya; Fernandes, Wagner de Souza; Murat, Paula Guerra; Medeiros, Márcio José de; Souza, Alda Izabel; Oliveira, Alessandra Gutierrez de; Galati, Eunice Aparecida Bianchi

    2017-02-01

    Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L. infantum

  13. Study of ionizing radiation as a tool for select promastigotes forms of Leishmania Amazonensis, and the megalomaniac response in experimental models

    International Nuclear Information System (INIS)

    Bonetti, Franco Claudio

    2006-01-01

    Actually, millions of people around the globe are under the risk of infection by a protozoan transmitted by a bit of a sand fly. This parasite is a Leishmania spp. This causes a wide spectrum disease, since a cutaneous disease to a visceral one. The cutaneous form is the major clinical manifestation (above 90%). The ionizing radiation, produced in a 60 Co font, had being successes used to promote physical-chemical transformations on different protozoan, including Leishmania spp. In previous work was determined that promastigotes forms of Leishmania amazonensis, irradiated with different doses of radiation, lost their viability maintaining, however, their immunogenicity. In this work, was studied the use of ionizing radiation as a tool for selection of meta cyclic forms of the parasite in axenic culture, for a possible efficient irradiated immuno gene production. Our results shown that cultures irradiated with 400 Gy of gamma irradiation, has 75% of metacyclic form, which are capable to produce, in vitro, an infection that is similar the natural occurrence. These irradiated parasites have their internal cellular structure modified, maintaining their external structure intact. Susceptible strain of mice immunized with leishmania irradiated with different doses had high immunoglobulin production, and maintained this production after the challenge with naive parasites. In other strains this default was similar, however in lower titles. Immunodeficient mice didn't produce immunoglobulin nor on the immunization or on the challenge. (author)

  14. Targeting Leishmania amazonensis amastigotes through macrophage internalisation of a hydroxymethylnitrofurazone nanostructured polymeric system.

    Science.gov (United States)

    Monteiro, Lis Marie; Löbenberg, Raimar; Ferreira, Elizabeth Igne; Cotrim, Paulo Cesar; Kanashiro, Edite; Rocha, Mussya; Chung, Man Chin; Bou-Chacra, Nadia

    2017-07-01

    Dextran-coated poly (n-butyl cyanoacrylate) nanoparticles (PBCA-NPs) were prepared and were evaluated for enhanced delivery of a promising anti-Leishmania drug candidate, hydroxymethylnitrofurazone (NFOH), to phagocytic cells. Currently available chemotherapy for leishmaniasis, such as pentavalent antimonials, presents low safety and efficacy. Furthermore, widespread drug resistance in leishmaniasis is rapidly emerging. To overcome these drawbacks, the use of nanosized delivery systems can reduce systemic drug toxicity and increase the drug concentration in infected macrophages, therefore improving treatment of leishmaniasis. PBCA-NPs containing NFOH (PBCA-NFOH-NPs) were prepared by an anionic emulsion polymerisation method. The z-average and polydispersity index (PDI) were determined by photon correlation spectroscopy, the zeta potential by microelectrophoresis and the entrapment efficiency by HPLC. Cytotoxicity was determined using macrophages from BALB/c mice. Efficacy tests were performed using Leishmania amazonensis promastigotes and amastigotes. The z-average of PBCA-NFOH-NPs was 151.5 ± 61.97 nm, with a PDI of 0.104 ± 0.01, a zeta potential of -10.1 ± 6.49 mV and an entrapment efficiency of 64.47 ± 0.43%. Efficacy in amastigotes revealed IC 50 values of 0.33 µM and 31.2 µM for the nanostructured and free NFOH, respectively (95-fold increase). The cytotoxicity study indicated low toxicity of the PBCA-NFOH-NPs to macrophages. The selectivity index was 370.6, which is 49-fold higher than free NFOH (7.6). Such findings indicated that improved efficacy could be due to NP internalisation following site-specific drug delivery and reactivation of immune protective reactions by the NP components. Thus, PBCA-NFOH-NPs have the potential to significantly improve the treatment of leishmaniasis, with reduced systemic side effects. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  15. An agent-based model for Leishmania major infection

    Science.gov (United States)

    Dancik, Garrett M.; Jones, Douglas E.; Dorman, Karin S.

    Leishmania are protozoan parasites transmitted by bites of infected sandflies. Over 20 species of Leishmania, endemic in 88 countries, are capable of causing human disease. Disease is either cutaneous, where skin ulcers occur on exposed surfaces of the body, or visceral, with near certain mortality if untreated. C3HeB/FeJ mice are resistant to L. major, but develop chronic cutaneous lesions when infected with another species L. amazonensis. The well-characterized mechanism of resistance to L. major depends on a CD4+ Thl immune response, macrophage activation, and elimination of the parasite [Sacks 2002]. The factors that account for host susceptibility to L. Amazonensis, however, are not completely understood, despite being generally attributed to a weakened Th1 response [Vanloubbeck 2004].

  16. Effects of seco-steroids purified from Physalis angulata L., Solanaceae, on the viability of Leishmania sp Efeitos de seco-esteróides purificados de Physalis angulata L., Solanaceae na viabilidade de Leishmania sp

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    Elisalva T. Guimarães

    2010-12-01

    Full Text Available Physalis angulata L., Solanaceae, is an annual herb commonly used in popular medicine in many tropical and subtropical countries. P. angulata extracts contain a variety of substances, but little is known about their pharmacological activities. In this work we investigated the in vitro antileishmanial activity of seco-steroids (physalins purified from P. angulata. Addition of physalins B, F, and G caused a concentration-dependent inhibition in the growth of L. amazonensis promastigotes, being the IC50 values were 6.8, 1.4, and 9.2 μM, respectively. Physalin D was less active and had an IC50 value of 30.5 μM. Physalins were also active in cultures of other Leishmania species (L. major, L. braziliensis, and L. chagasi. Our results demonstrate the potent antileishmanial activity of physalins in cultures of Leishmania species of the New and Old Worlds and suggest the therapeutic potential of these seco-steroids in leishmaniasis.Physalis angulata L., Solanaceae, é uma erva anual utilizada na medicina popular em muitos países tropicais e subtropicais. Apesar dos extratos da P. angulata apresentarem uma grande variedade de substâncias, pouco é conhecido sobre a sua atividade farmacológica. Neste trabalho foi investigado a atividade antileishmania in vitro de seco-esteroides (fisalinas purificados da P. angulata. O tratamento com as fisalinas B, F e G causou uma inibição concentração-dependente do crescimento de promastigotas de Leishmania amazonensis em cultura axênica, com valores de IC50 de 6,8, 1,4, e 9,2 μM respectivamente. A fisalina D foi menos ativa, com valores de IC50 de 30,5 μM. Foi também observada uma atividade leishmanicida em culturas de outras espécies de Leishmania (L. major, L. braziliensis e L. chagasi. Nossos resultados demonstram que as fisalinas inibem o crescimento dos promastigotas com o tratamento de espécies de Leishmania do Velho e do Novo Mundos e sugerem o potencial terapêutico destas moléculas na

  17. Effect of aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing amino acids on Leishmania spp. chemotaxis.

    Science.gov (United States)

    Diaz, E; Zacarias, A K; Pérez, S; Vanegas, O; Köhidai, L; Padrón-Nieves, M; Ponte-Sucre, A

    2015-11-01

    In the sand-fly mid gut, Leishmania promastigotes are exposed to acute changes in nutrients, e.g. amino acids (AAs). These metabolites are the main energy sources for the parasite, crucial for its differentiation and motility. We analysed the migratory behaviour and morphological changes produced by aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing AAs in Leishmania amazonensis and Leishmania braziliensis and demonstrated that L-methionine (10-12 m), L-tryptophan (10-11 m), L-glutamine and L-glutamic acid (10-6 m), induced positive chemotactic responses, while L-alanine (10-7 m), L-methionine (10-11 and 10-7 m), L-tryptophan (10-11 m), L-glutamine (10-12 m) and L-glutamic acid (10-9 m) induced negative chemotactic responses. L-proline and L-cysteine did not change the migratory potential of Leishmania. The flagellum length of L. braziliensis, but not of L. amazonensis, decreased when incubated in hyperosmotic conditions. However, chemo-repellent concentrations of L-alanine (Hypo-/hyper-osmotic conditions) and L-glutamic acid (hypo-osmotic conditions) decreased L. braziliensis flagellum length and L-methionine (10-11 m, hypo-/hyper-osmotic conditions) decreased L. amazonensis flagellum length. This chemotactic responsiveness suggests that Leishmania discriminate between slight concentration differences of small and structurally closely related molecules and indicates that besides their metabolic effects, AAs play key roles linked to sensory mechanisms that might determine the parasite's behaviour.

  18. Selective effect of 2',6'-dihydroxy-4'-methoxychalcone isolated from Piper aduncum on Leishmania amazonensis.

    Science.gov (United States)

    Torres-Santos, E C; Moreira, D L; Kaplan, M A; Meirelles, M N; Rossi-Bergmann, B

    1999-05-01

    2',6'-Dihydroxy-4'-methoxychalcone (DMC) was purified from the dichloromethane extract of Piper aduncum inflorescences. DMC showed significant activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis, with 50% effective doses of 0.5 and 24 micrograms/ml, respectively. Its inhibitory effect on amastigotes is apparently a direct effect on the parasites and is not due to activation of the nitrogen oxidative metabolism of macrophages, since the production of nitric oxide by both unstimulated and recombinant gamma interferon-stimulated macrophages was decreased rather than increased with DMC. The phagocytic activity of macrophages was functioning normally even with DMC concentrations as high as 80 micrograms/ml, as seen by electron microscopy and by the uptake of fluorescein isothiocyanate-labeled beads. Ultrastructural studies also showed that in the presence of DMC the mitochondria of promastigotes were enlarged and disorganized. Despite destruction of intracellular amastigotes, no disarrangement of macrophage organelles were observed, even at 80 micrograms of DMC/ml. These observations suggest that DMC is selectively toxic to the parasites. Its simple structure may well enable it to serve as a new lead compound for the synthesis of novel antileishmanial drugs.

  19. Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae

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    MICHALSKY Érika M.

    2002-01-01

    Full Text Available DNA amplification by the polymerase chain reaction (PCR was applied in the investigation of the presence of Leishmania (Kinetoplastida: Trypanosomatidae parasites in single phlebotomine sandflies. Three phlebotomine/parasite pairs were used: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia migonei/Leishmania amazonensis and Lutzomyia migonei/Leishmania braziliensis, all of them incriminated in the transmission of visceral or cutaneous leishmaniasis. DNA extraction was performed with whole insects, with no need of previous digestive tract dissection or pooling specimens. The presence of either mouse blood in the digestive tract of the sandflies or the digestive tract itself did not interfere in the PCR. Infection by as few as 10 Leishmania sp. per individual were sufficient for DNA amplification with genus-specific primers. Using primers for L. braziliensis and L. mexicana complexes, respectively, it was possible to discriminate between L. braziliensis and L. amazonensis in experimentally infected vectors (L. migonei.

  20. [Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi].

    Science.gov (United States)

    Arrivillaga-Henríquez, Jazzmín; Enríquez, Sandra; Romero, Vanessa; Echeverría, Gustavo; Pérez-Barrera, Jorge; Poveda, Ana; Navarro, Juan-Carlos; Warburg, Alon; Benítez, Washington

    2017-03-29

    The province of Pichincha in Ecuador is an endemic area of cutaneous leishmaniasis, where anthropophilic sand flies with natural infection by Leishmania, have been reported as vectors. However, the role in transmission of zoophilic species has not been evaluated. To evaluate natural infection by Leishmania in two zoophilic phlebotomine sand fly species, Lutzomyia reburra and Lu. barrettoi majuscula, and one anthropophilic species, Lu. trapidoi, as well as the endophagy and synanthropism of these species in the northwest of Pichincha. Phlebotomines were collected using CDC light traps in different habitats and altitudes with presence of cutaneous leishmaniasis. Leishmania infection was detected using genomic DNA from females of the collected sand flies. We amplified the internal transcribed spacer gene of ribosomal RNA I (ITS1), the mitochondrial topoisomerase II gene (mtTOPOII), and the nuclear topoisomerase II gene (TopoII). Percentages of positivity for Leishmania, at spatio-temporal scale, proportion of endophagy and synanthropism index were calculated. Natural infection was determined for Le. amazonensis in Lu. reburra (9.5%) and Lu. b. majuscula (23.8%), while in Lu. trapidoi we detected Le. amazonensis, Le. brazilienis and Le. naiffi-lainsoni. Phlebotomines were asynanthropic and with low endophagy. Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

  1. Lutzomyia reducta Feliciangeli et al., 1988, a host of Leishmania amazonensis, sympatric with two other members of the Flaviscutellata complex in southern Amazonas and Rondônia, Brazil (Diptera: Psychodidae Lutzomyia reducta Feliciangeli et al., 1988 um hospedeiro de Leishmania amazonensis, simpátrico com duas outras espécies do complexo flaviscutellata no sul do Amazonas e Rondônica, Brasil (Diptera: Psychodidae

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    R. A. Freitas

    1989-09-01

    Full Text Available A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzomyia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são inclu

  2. Selective Effect of 2′,6′-Dihydroxy-4′-Methoxychalcone Isolated from Piper aduncum on Leishmania amazonensis

    Science.gov (United States)

    Torres-Santos, Eduardo Caio; Moreira, Davyson Lima; Kaplan, Maria Auxiliadora C.; Meirelles, Maria Nazareth; Rossi-Bergmann, Bartira

    1999-01-01

    2′,6′-Dihydroxy-4′-methoxychalcone (DMC) was purified from the dichloromethane extract of Piper aduncum inflorescences. DMC showed significant activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis, with 50% effective doses of 0.5 and 24 μg/ml, respectively. Its inhibitory effect on amastigotes is apparently a direct effect on the parasites and is not due to activation of the nitrogen oxidative metabolism of macrophages, since the production of nitric oxide by both unstimulated and recombinant gamma interferon-stimulated macrophages was decreased rather than increased with DMC. The phagocytic activity of macrophages was functioning normally even with DMC concentrations as high as 80 μg/ml, as seen by electron microscopy and by the uptake of fluorescein isothiocyanate-labeled beads. Ultrastructural studies also showed that in the presence of DMC the mitochondria of promastigotes were enlarged and disorganized. Despite destruction of intracellular amastigotes, no disarrangement of macrophage organelles were observed, even at 80 μg of DMC/ml. These observations suggest that DMC is selectively toxic to the parasites. Its simple structure may well enable it to serve as a new lead compound for the synthesis of novel antileishmanial drugs. PMID:10223942

  3. 17-AAG kills intracellular Leishmania amazonensis while reducing inflammatory responses in infected macrophages.

    Science.gov (United States)

    Petersen, Antonio Luis de Oliveira Almeida; Guedes, Carlos Eduardo Sampaio; Versoza, Carolina Leite; Lima, José Geraldo Bomfim; de Freitas, Luiz Antônio Rodrigues; Borges, Valéria Matos; Veras, Patrícia Sampaio Tavares

    2012-01-01

    Leishmaniasis is a neglected endemic disease with a broad spectrum of clinical manifestations. Pentavalent antimonials have been the treatment of choice for the past 70 years and, due to the emergence of resistant cases, the efficacy of these drugs has come under scrutiny. Second-line drugs are less efficacious, cause a range of side effects and can be costly. The formulation of new generations of drugs, especially in developing countries, has become mandatory. We investigated the anti-leishmanial effect of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, in vitro. This inhibitor is currently in clinical trials for cancer treatment; however, its effects against intracellular Leishmania remain untested. Macrophages infected with L. amazonensis were treated with 17-AAG (25-500 nM) and parasite load was quantified using optical microscopy. Parasite load declined in 17-AAG-treated macrophages in a dose- and time-dependent manner. Intracellular parasite death became irreversible after 4 h of treatment with 17-AAG, and occurred independent of nitric oxide (NO) and superoxide (O(2) (-)) production. Additionally, intracellular parasite viability was severely reduced after 48 h of treatment. Interestingly, treatment with 17-AAG reduced pro-inflammatory mediator production, including TNF-α, IL-6 and MCP-1, yet IL-12 remained unaffected. Electron microscopy revealed morphological alterations, such as double-membrane vacuoles and myelin figures at 24 and 48 h after 17-AAG treatment. The HSP90 inhibitor, 17-AAG, possesses high potency under low dosage and reduces both pro-inflammatory and oxidative molecule production. Therefore, further studies are warranted to investigate this inhibitor's potential in the development of new generations of anti-leishmanials.

  4. Efficacy of the photodynamic antimicrobial therapy (PACT) with the use of methylene blue associated with the λ660nm laser in Leishmania (Leishmania) amazonesis: in vitro study

    Science.gov (United States)

    Pires-Santos, Gustavo M.; Marques, Aparecida M. C.; Alves, Eliomara S. S.; Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Rosa, Cristiane B.; Colombo, Fabio; Pinheiro, Antônio L. B.; Vannier-Santos, Marcos A.

    2012-03-01

    The present studied evaluated the in vitro effects of PDT on Leishmania (Leishmania) amazonensis promastigotes. For this examination L. amazonensis promastigotes, stain Josefa, were used and maintained in Warren media supplement with fetal bovine serum at 26°C for 96 hours. A viability curve was accomplished using different concentrations of methylene blue photosensitizer associated to red laser light in order to obtain the most effective interaction to inhibit the parasite's growth. Two pre-irradiation periods, 5 and 30 minutes, were evaluated and the promastigotes were counted by colorimetry. On fluorescence microscopy the autophagic processes and reactive oxygen species were detected. Promastigotes treated with Photodynamic Therapy (PDT) by concentrations of 5 and 0,315ug/mL, presented cellular proliferation inhibition when compared to the control. In the first condition, the cells had structural alterations such as truncated cells, cells with two flagella, bleb formation and cells body deformation, while none of these modifications could be visualized in the control group. When analyzed through fluorescence microscopy, the promastigotes treated were positives for free radicals immediately after light application and also 1 hour after treatment presenting signs of autophagia. PDT on L. (L.) amazonensis is effective causing alterations that can help elucidate the mechanisms of the parasite's death when treated with methilene

  5. Lulo cell line derived from Lutzomyia longipalpis (Diptera: Psychodidae): a novel model to assay Leishmania spp. and vector interaction.

    Science.gov (United States)

    Côrtes, Luzia Mc; Silva, Roger Mm; Pereira, Bernardo As; Guerra, Camila; Zapata, Angela C; Bello, Felio J; Finkelstein, Léa C; Madeira, Maria F; Brazil, Reginaldo P; Côrte-Real, Suzana; Alves, Carlos R

    2011-11-14

    Leishmania (Vianna) braziliensis, Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) chagasi are important parasites in the scenario of leishmaniasis in Brazil. During the life cycle of these parasites, the promastigote forms adhere to the midgut epithelial microvillii of phlebotomine insects to avoid being secreted along with digestive products. Lulo cells are a potential model that will help to understand the features of this adhesion phenomenon. Here, we analyze the interaction between Leishmania spp. promastigotes and Lulo cells in vitro, specifically focusing on adhesion events occurring between three Leishmania species and this cell line. Confluent monolayers of Lulo cells were incubated with promastigotes and adhesion was assessed using both light microscopy and scanning electron microscopy. The results indicate that species from the subgenera Leishmania and Viannia have great potential to adhere to Lulo cells. The highest adherence rate was observed for L. (L.) chagasi after 24 h of incubation with Lulo cells (27.3 ± 1.8% of cells with adhered promastigotes), followed by L. (L.) amazonensis (16.0 ± 0.7%) and L. (V.) braziliensis (3.0 ± 0.7%), both after 48 h. In the ultrastructural analysis, promastigote adherence was also assessed by scanning electron microscopy, showing that, for parasites from both subgenera, adhesion occurs by both the body and the flagellum. The interaction of Lulo cells with Leishmania (L.) chagasi showed the participation of cytoplasmic projections from the former closely associating the parasites with the cells. We present evidence that Lulo cells can be useful in studies of insect-parasite interactions for Leishmania species.

  6. DFT/PCM, QTAIM, 1H NMR conformational studies and QSAR modeling of thirty-two anti-Leishmania amazonensis Morita-Baylis-Hillman Adducts

    Science.gov (United States)

    Filho, Edilson B. A.; Moraes, Ingrid A.; Weber, Karen C.; Rocha, Gerd B.; Vasconcellos, Mário L. A. A.

    2012-08-01

    Morita-Baylis-Hillman Adducts (MBHA) has been recently synthesized and bio-evaluated by our research group against Leishmania amazonensis, parasite that causes cutaneous and mucocutaneous leishmaniasis. We present here a theoretical conformational study of thirty-two leismanicidal MBHA by B3LYP/6-31+g(d) calculations with Polarized Continuum Model (PCM) to simulate water influence. Intramolecular Hydrogen Bonds (IHBs) indicated to control the most conformational preferences of MBHA. Quantum Theory Atoms in Molecules (QTAIM) calculations were able to characterize these interactions at Bond Critical Point level. Compounds presenting an unusual seven member IHB between NO2 group and hydroxyl moiety, supported by experimental spectroscopic data, showed a considerable improvement of biological activity (lower IC50 values). These results are in accordance to redox NO2 mechanism of action. Based on structural observations, some molecular descriptors were calculated and submitted to Quantitative Structure-Activity Relationship (QSAR) studies through the PLS Regression Method. These studies provided a model with good validation parameters values (R2 = 0.71, Q2 = 0.61 and Qext2 = 0.92).

  7. The transmission of suprapylarian Leishmania by bite of experimentally infected sand flies (Diptera: Psychodidae A trasnmissão de Leishmania suprapilária pela picada do flebotomíneo infectado experimentalmente

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    L. Ryan

    1987-09-01

    Full Text Available Lutzomyia furcata transmitted Leishmania chagasi to a hamster 10 days after being experimentally fed on an infected spleen. An individual female Psychodopygus carrerai carrerai that had fed on a hamster lesion caused by Leishmania mexicana amazonensis transmitted this parasite 6 days later to another hamster. Transmission electron microscopy of this fly's head revealed a small number of degenerate promastigotes in the foregut, but only a few were attached.O protozoário Leishmania (L. chagasi foi transmitido experimentalmente a um hamster pela picada do flebotomíneo Lutzomyia furcata. Os insetos foram infectados através de uma membrana (pele de pinto, utilizando-se formas amastigotas provenientes do baço de um hamster infectado. O baço foi triturado em sangue de coelho. A L. (L. amazonensis foi transmitida a um hamster pela picada do flebotomíneo Psychodopygus c. carrerai, previamente alimentado em lesão de pele de um outro hamster infectado com o parasita. O exame desse flebotomíneo, através de microscópio eletrônico, revelou um número pequeno de flagelados degenerados, livres no lumen do intestino anterior.

  8. An effective in vitro and in vivo antileishmanial activity and mechanism of action of 8-hydroxyquinoline against Leishmania species causing visceral and tegumentary leishmaniasis.

    Science.gov (United States)

    Costa Duarte, Mariana; dos Reis Lage, Letícia Martins; Lage, Daniela Pagliara; Mesquita, Juliana Tonini; Salles, Beatriz Cristina Silveira; Lavorato, Stefânia Neiva; Menezes-Souza, Daniel; Roatt, Bruno Mendes; Alves, Ricardo José; Tavares, Carlos Alberto Pereira; Tempone, André Gustavo; Coelho, Eduardo Antonio Ferraz

    2016-02-15

    The development of new therapeutic strategies to treat leishmaniasis has become a priority. In the present study, the antileishmanial activity of 8-hydroxyquinoline (8-HQN) was investigated against in vitro promastigotes and in vivo intra-macrophage amastigotes of three Leishmania species: Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis. Studies were performed to establish the 50% Leishmania inhibitory concentration (IC50) of 8-HQN, as well as its 50% cytotoxic concentration (CC50) on murine macrophages and in human red blood cells. The inhibition of macrophages infection was also evaluated using parasites that were pre-treated with 8-HQN. The effects of this compound on nitric oxide (NO) production and in the mitochondrial membrane potential were also evaluated. Finally, the therapeutic efficacy of 8-HQN was assessed in a known murine model, L. amazonensis-chronically infected BALB/c mice. Our results showed that 8-HQN was effective against promastigote and amastigote stages of all tested Leishmania species, presenting a selectivity index of 328.0, 62.0 and 47.0 for L. amazonensis, L. infantum and L. braziliensis, respectively. It was effective in treating infected macrophages, as well as in preventing the infection of these cells using pre-treated parasites. In addition, 8-HQN caused an alteration in the mitochondrial membrane potential of the parasites. When administered at 10mg/kg body weight/day by subcutaneous route, this product was effective in reducing the lesion diameter, as well as the parasite load in evaluated tissues and organs of infected animals. The results showed the in vitro and in vivo efficacy of 8-HQN against three different Leishmania species causing tegumentary and/or visceral leishmaniasis, and it could well be used for future therapeutic optimization studies to treat leishmaniasis. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

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    Tâmara Dias Oliveira Machado

    Full Text Available BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season and November (rainy season in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp. and 578 (22 spp. were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins

  10. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna.

    Science.gov (United States)

    Machado, Tâmara Dias Oliveira; Minuzzi-Souza, Thaís Tâmara Castro; Ferreira, Tauana de Sousa; Freire, Luciana Pereira; Timbó, Renata Velôzo; Vital, Tamires Emanuele; Nitz, Nadjar; Silva, Mariana Neiva; Santos, Alcinei de Souza; Sales, Nathyla Morgana Cunha; Obara, Marcos Takashi; Andrade, Andrey José de; Gurgel-Gonçalves, Rodrigo

    2017-10-01

    Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.

  11. ITS1 PCR-RFLP Diagnosis and Characterization of Leishmania in Clinical Samples and Strains from Cases of Human Cutaneous Leishmaniasis in States of the Mexican Southeast

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    Amalia Monroy-Ostria

    2014-01-01

    Full Text Available American cutaneous leishmaniasis includes a spectrum of clinical forms localized cutaneous, diffuse cutaneous, and mucocutaneous leishmaniasis which can be caused by different strains of Leishmania belonging to the L. mexicana or L. braziliensis complexes which may coexist in the same endemic area. We evaluated the PCR-RFLP assay of the ITS1 genes for direct identification of Leishmania species in 163 clinical samples and 21 Mexican isolates of Leishmania. In relation to the Mexican isolates of Leishmania 52% displayed a pattern similar to the L. (L. mexicana, 5% showed a mixed pattern compatible with L. (L. mexicana and L. (V. braziliensis, eight with L. (L. amazonensis and L. (L. mexicana, and one to L. (V. braziliensis. Most of the clinical samples, 109/116 (94%, gave a pattern similar to that of the L. mexicana, two clinical samples gave similar patterns to that of Leishmania braziliensis, and 5 samples gave patterns that suggest a coinfection of L. (L. mexicana and L. (V. braziliensis or L. (L. mexicana and L. (L. amazonensis. The ITS1 PCR-RFLP assay is a multipurpose tool for diagnosis of Leishmania from clinical samples and enables determination of the infecting species of New World Leishmania in the field in relatively short time and low cost.

  12. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    International Nuclear Information System (INIS)

    Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N.; Andrade Junior, H.F.

    1999-01-01

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a 60 Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author)

  13. The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo

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    Sergio Sifontes-Rodríguez

    2015-04-01

    Full Text Available Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC and 50% inhibitory concentration (IC50 values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl-furan (furvina and 2-bromo-5-(2-methyl-2-nitrovinyl-furan (UC245 also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r (a furvina-containing antifungal ointment for the treatment of CL.

  14. Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi

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    Jazzmín Arrivillaga-Henríquez

    2017-03-01

    Conclusion: Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

  15. Differentiation of Leishmania species by FT-IR spectroscopy

    Science.gov (United States)

    Aguiar, Josafá C.; Mittmann, Josane; Ferreira, Isabelle; Ferreira-Strixino, Juliana; Raniero, Leandro

    2015-05-01

    Leishmaniasis is a parasitic infectious disease caused by protozoa that belong to the genus Leishmania. It is transmitted by the bite of an infected female Sand fly. The disease is endemic in 88 countries Desjeux (2001) [1] (16 developed countries and 72 developing countries) on four continents. In Brazil, epidemiological data show the disease is present in all Brazilian regions, with the highest incidences in the North and Northeast. There are several methods used to diagnose leishmaniasis, but these procedures have many limitations, are time consuming, have low sensitivity, and are expensive. In this context, Fourier Transform Infrared Spectroscopy (FT-IR) analysis has the potential to provide rapid results and may be adapted for a clinical test with high sensitivity and specificity. In this work, FT-IR was used as a tool to investigate the promastigotes of Leishmaniaamazonensis, Leishmaniachagasi, and Leishmaniamajor species. The spectra were analyzed by cluster analysis and deconvolution procedure base on spectra second derivatives. Results: cluster analysis found four specific regions that are able to identify the Leishmania species. The dendrogram representation clearly indicates the heterogeneity among Leishmania species. The band deconvolution done by the curve fitting in these regions quantitatively differentiated the polysaccharides, amide III, phospholipids, proteins, and nucleic acids. L. chagasi and L. major showed a greater biochemistry similarity and have three bands that were not registered in L. amazonensis. The L. amazonensis presented three specific bands that were not recorded in the other two species. It is evident that the FT-IR method is an indispensable tool to discriminate these parasites. The high sensitivity and specificity of this technique opens up the possibilities for further studies about characterization of other microorganisms.

  16. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia; Andrade Junior, H.F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Inst. de Medicina Tropical

    1999-11-01

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a {sup 60} Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author) 13 refs., 3 figs.

  17. Effects of Bone Marrow Mesenchymal Stromal Cell Therapy in Experimental Cutaneous Leishmaniasis in BALB/c Mice Induced by Leishmania amazonensis

    Science.gov (United States)

    Pereira, Joyce Carvalho; Ramos, Tadeu Diniz; Silva, Johnatas Dutra; de Mello, Mirian França; Pratti, Juliana Elena Silveira; da Fonseca-Martins, Alessandra Marcia; Firmino-Cruz, Luan; Kitoko, Jamil Zola; Chaves, Suzana Passos; Gomes, Daniel Claudio De Oliveira; Diaz, Bruno Lourenço; Rocco, Patricia R. M.; de Matos Guedes, Herbert Leonel

    2017-01-01

    Cutaneous leishmaniasis remains both a public health and a therapeutic challenge. To date, no ideal therapy for cutaneous leishmaniasis has been identified, and no universally accepted therapeutic regimen and approved vaccines are available. Due to the mesenchymal stromal cell (MSC) immunomodulatory capacity, they have been applied in a wide variety of disorders, including infectious, inflammatory, and allergic diseases. We evaluated the potential effects of bone marrow MSC therapy in a murine model of cutaneous leishmaniasis. In vitro, coculture of infected macrophages with MSC increased parasite load on macrophages in comparison with controls (macrophages without MSCs). In vivo, BALB/c mice were infected with 2 × 106 Leishmania amazonensis (Josefa strain) promastigotes in the footpad. 7 and 37 days after infection, animals were treated with 1 × 105 MSCs, either intralesional (i.l.), i.e., in the same site of infection, or intravenously (i.v.), through the external jugular vein. Control animals received the same volume (50 µL) of phosphate-buffered saline by i.l. or i.v. routes. The lesion progression was assessed by its thickness measured by pachymetry. Forty-two days after infection, animals were euthanized and parasite burden in the footpad and in the draining lymph nodes was quantified by the limiting dilution assay (LDA), and spleen cells were phenotyped by flow cytometry. No significant difference was observed in lesion progression, regardless of the MSC route of administration. However, animals treated with i.v. MSCs presented a significant increase in parasite load in comparison with controls. On the other hand, no harmful effect due to MSCs i.l. administered was observed. The spleen cellular profile analysis showed an increase of IL-10 producing T CD4+ and TCD8+ cells in the spleen only in mice treated with i.v. MSC. The excessive production of IL-10 could be associated with the disease-aggravating effects of MSC therapy when intravenously

  18. Leishmania replication protein A-1 binds in vivo single-stranded telomeric DNA

    International Nuclear Information System (INIS)

    Neto, J.L. Siqueira; Lira, C.B.B.; Giardini, M.A.; Khater, L.; Perez, A.M.; Peroni, L.A.; Reis, J.R.R. dos; Freitas-Junior, L.H.; Ramos, C.H.I.; Cano, M.I.N.

    2007-01-01

    Replication protein A (RPA) is a highly conserved heterotrimeric single-stranded DNA-binding protein involved in different events of DNA metabolism. In yeast, subunits 1 (RPA-1) and 2 (RPA-2) work also as telomerase recruiters and, in humans, the complex unfolds G-quartet structures formed by the 3' G-rich telomeric strand. In most eukaryotes, RPA-1 and RPA-2 bind DNA using multiple OB fold domains. In trypanosomatids, including Leishmania, RPA-1 has a canonical OB fold and a truncated RFA-1 structural domain. In Leishmania amazonensis, RPA-1 alone can form a complex in vitro with the telomeric G-rich strand. In this work, we show that LaRPA-1 is a nuclear protein that associates in vivo with Leishmania telomeres. We mapped the boundaries of the OB fold DNA-binding domain using deletion mutants. Since Leishmania and other trypanosomatids lack homologues of known telomere end binding proteins, our results raise questions about the function of RPA-1 in parasite telomeres

  19. Leishmania amazonensis chemotaxis under glucose gradient studied by the strength and directionality of forces measured with optical tweezers

    Science.gov (United States)

    de Ysasa Pozzo, Liliana; Fontes, Adriana; de Thomaz, André A.; Barbosa, Luiz Carlos; Ayres, Diana Copi; Giorgio, Selma; Cesar, Carlos Lenz

    2007-02-01

    Chemotaxis is the mechanism microorganisms use to sense the environment surrounding them and to direct their movement towards attractive, or away from the repellent, chemicals. The biochemical sensing is almost the only way for communication between unicellular organisms. Prokaryote and Eukaryote chemotaxis has been mechanically studied mainly by observing the directionality and timing of the microorganisms movements subjected to a chemical gradient, but not through the directionality and strength of the forces it generates. To observe the vector force of microorganisms under a chemical gradient we developed a system composed of two large chambers connected by a tiny duct capable to keep the chemical gradient constant for more than ten hours. We also used the displacements of a microsphere trapped in an Optical Tweezers as the force transducer to measure the direction and the strength of the propulsion forces of flagellum of the microorganism under several gradient conditions. A 9μm diameter microsphere particle was trapped with a Nd:YAG laser and its movement was measured through the light scattered focused on a quadrant detector. We observed the behavior of the protozoa Leishmania amazonensis (eukaryote) under several glucose gradients. This protozoa senses the gradient around it by swimming in circles for three to five times following by tumbling, and not by the typical straight swimming/tumbling of bacteria. Our results also suggest that force direction and strength are also used to control its movement, not only the timing of swimming/tumbling, because we observed a higher force strength clearly directed towards the glucose gradient.

  20. Evaluación de la respuesta de isotipos de inmunoglobulina especifica a Leishmania en leishmaniasis tegumentaria Americana Evaluation of specific immunoglobin isotype response to Leishmania in American tegumentary leishmaniasis

    Directory of Open Access Journals (Sweden)

    Maricel Labrada

    1989-09-01

    Full Text Available Con el fin de determinar las clases de anticuerpo producido contra el parásito y la cinética de los mismos en relación a la evolución de la infección, se estudiaron los sueros de 133 pacientes infectados con Leishmania del complejo braziliensis. Se utilizó la prueba de inmunofluorescencia indirecta y amastigotas de L. mexicana amazonensis como antígeno. En los sueros obtenidos al momento de consultar para el diagnóstico se encontró IgM en 54 de los sueros absorbidos con Straphylococcus aureus Cowan I y en 5 de los no absorbidos. La IgM sólo se encontro en los sueros de pacientes con tiempo devolución de las lesiones Leishmania-specific immunoglobulin subclass response was evaluated in 133 patients infected with Leishmania braziliensis. The indirect immunofluorescent antibody test (IFAT was employed with amastigotes of L. mexicana amazonensis as antigen. Among the 133 sera obtained at consultation fo rdiagnosis of active lesions, IgM was detected in 54 following absorption with Staphylococcus aureus Cowan strain I, and in 5 sera prior to absorption. IgM reactive with Leishmania antigen was only found in sera from patients whose lesions had envolved over past two months or less. Leishmania-specific IgG was detected in all sera prior to absorption. Sera obtained at the time of recurrence of after complete healing of lesions presented only specific IgC. The combined use of the Montenegro skin test and specific IgM increased the sensitivity of immunodiagnostic methods in patients with lesions of less than 2 months duration. Normal control volunteers were negative for specific IgM and unreactive to Montenegro skin testin. Among 16 patients with non-leishmanial lesion, 3 with sporotrichosis showed IgG reactive with Leishmania; none, including 4 with lesions of less than two months duration, showed specific IgM. We conclude that in patients infected with L. brasiliensis the presence of specific IgG and IgM is associated with the time of

  1. Evaluación del efecto del ácido nalidíxico, ampicilina, kanamicina, penicilina G y polimixina B en los cultivos de promastigotes de leishmania

    Directory of Open Access Journals (Sweden)

    Sofía Duque Beltrán

    1992-06-01

    Full Text Available Se evaluó el efecto de diferentes concentraciones de ácido nalidíxico, ampicilina, kanarnicina, penicilina G y polimixina B, sobre la población de promastigotes de Leishmania braziliensis braziliensis , Leishmania donovani chagasi y Leishmania mexicana amazonensis in vitro. La penicilina G y la ampicilina se pueden utilizar hasta concentraciones de 1000 ug/ml y 500 ug/ml respectivamente en cultivo de promastigotes de cualquier cepa de Leishmania sin que éstos se afecten. La polimixina B disminuye la población de prosmastigotes por lo cual es preferible no usarse en cultivos de Leishmania. El ácido nalidíxico y kanamicina pueden ser utilizados in vitro pero teniéndose en cuenta la especie de Leishmania y la concentración de anfimicrobiano recomendado para la misma.

  2. Extracellular vesicles from Leishmania-infected macrophages confer an anti-infection cytokine-production profile to naïve macrophages.

    Directory of Open Access Journals (Sweden)

    André Cronemberger-Andrade

    2014-09-01

    Full Text Available Extracellular vesicles (EVs are structures with phospholipid bilayer membranes and 100-1000 nm diameters. These vesicles are released from cells upon activation of surface receptors and/or apoptosis. The production of EVs by dendritic cells, mast cells, macrophages, and B and T lymphocytes has been extensively reported in the literature. EVs may express MHC class II and other membrane surface molecules and carry antigens. The aim of this study was to investigate the role of EVs from Leishmania-infected macrophages as immune modulatory particles.In this work it was shown that BALB/c mouse bone marrow-derived macrophages, either infected in vitro with Leishmania amazonensis or left uninfected, release comparable amounts of 50-300 nm-diameter extracellular vesicles (EVs. The EVs were characterized by flow cytometry and electron microscopy. The incubation of naïve macrophages with these EVs for 48 hours led to a statistically significant increase in the production of the cytokines IL-12, IL-1β, and TNF-α.EVs derived from macrophages infected with L. amazonensis induce other macrophages, which in vivo could be bystander cells, to produce the proinflammatory cytokines IL-12, IL-1β and TNF-α. This could contribute both to modulate the immune system in favor of a Th1 immune response and to the elimination of the Leishmania, leading, therefore, to the control the infection.

  3. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    Science.gov (United States)

    Amorim, Layane Valéria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ-elemene (14.25%), and trans-β-elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04 μg·mL−1) and amastigotes (IC50, 1.92 μg·mL−1) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400 μg·mL−1); however, there appeared to be no toxicity at 50 μg·mL−1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity. PMID:23533469

  4. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Klinger Antonio da Franca Rodrigues

    2013-01-01

    Full Text Available Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO by using gas chromatography-mass spectrometry (GC-MS and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%, with curzerene (47.3%, γ-elemene (14.25%, and trans-β-elemenone (10.4% being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04 μg·mL−1 and amastigotes (IC50, 1.92 μg·mL−1 suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400 μg·mL−1; however, there appeared to be no toxicity at 50 μg·mL−1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

  5. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action.

    Science.gov (United States)

    Rodrigues, Klinger Antonio da Franca; Amorim, Layane Valéria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ -elemene (14.25%), and trans- β -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04  μ g·mL(-1)) and amastigotes (IC50, 1.92  μ g·mL(-1)) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400  μ g·mL(-1)); however, there appeared to be no toxicity at 50  μ g·mL(-1). While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

  6. Kinetics of growth of Leishmania (Leishmania chagasi cycle in McCoy cell culture Cinéticas de crescimento do ciclo da Leishmania (Leishmania chagasi em cultura de células McCoy

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    Yeda L. Nogueira

    2006-12-01

    Full Text Available The kinetics of growth of Leishmania performed in vitro after internalization of the promastigote form in the cell and the occurrence of the transformation of the parasite into the amastigote form have been described by several authors. They used explants of macrophages in hamster spleen cell culture or in a human macrophage lineage cell, the U937. Using microscopy, the description of morphologic inter-relationship and the analysis of the production of specific molecules, it has been possible to define some of the peculiarities of the biology of the parasite. The present study shows the growth cycle of Leishmania chagasi during the observation of kinetic analysis undertaken with a McCoy cell lineage that lasted for a period of 144 hours. During the process, the morphologic transformation was revealed by indirect immunofluorescence (IF and the molecules liberated in the extra cellular medium were observed by SDS-PAGE at 24-hour intervals during the whole 144-hour period. It was observed that in the first 72 hours the promastigote form of L. chagasi adhered to the cell membranes and assumed a rounded (amastigote-like form. At 96 hours the infected cells showed morphologic alterations; at 120 hours the cells had liberated soluble fluorescent antigens into the extra cellular medium. At 144 hours, new elongated forms of the parasites, similar to promastigotes, were observed. In the SDS-PAGE, specific molecular weight proteins were observed at each point of the kinetic analysis showing that the McCoy cell imitates the macrophage and may be considered a useful model for the study of the infection of the Leishmania/cell binomial.Cinéticas de crescimento de Leishmania realizadas in vitro após a internalização da forma promastigota na célula e a ocorrência da transformação do parasito na forma amastigota foram descritas por vários autores, seja com a utilização de explantes de macrófagos em células de baço de hamster ou atualmente da c

  7. Efeito leishmanicida in vitro de Stachytarpheta cayennensis (Rich. Vahl (Verbenaceae

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    Rosilene C.R. Moreira

    Full Text Available A atividade anti-Leishmania do extrato hidroalcoólico de Stachytarpheta cayennensis, espécie utilizada popularmente no tratamento de lesões cutâneas causadas por Leishmania sp, foi testado em ensaios in vitro utilizando formas promastigotas de Leishmania braziliensis e L. amazonensis. O extrato hidroalcoólico foi preparado a partir das folhas secas e utilizado em culturas de L. amazonensis e L. braziliensis nas concentrações de 500 a 32,5 µg/mL. Após 24 horas as formas promastigotas foram quantificadas para o cálculo da CI50. A citotoxicidade do extrato foi avaliada também em culturas de macrófagos peritoneais. O extrato apresentou efeito leishmanicida dose e espécie-dependente para promastigotas de Leishmania sendo mais eficaz para L. braziliensis. O extrato não apresentou efeito citotóxico quando utilizado nas culturas de macrófagos. Concluiu-se que o extrato hidroalcoólico de S. cayennensis inibe formas promastigotas de Leishmania in vitro o que poderia justificar, pelo menos parcialmente, o uso popular dessa espécie no tratamento de úlceras causadas por Leishmania.

  8. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with {sup 60}Co gamma rays, in Leishmania spp; Acao do veneno de Bothrops moojeni e sua fracao L-aminoacido oxidase, submetida ao tratamento com raios gama de {sup 60}Co, em Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Andre Gustavo Tempone

    1999-07-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 {mu}g/ml (EC{sub 50}), L.(V.) panamensis (0.78 |{mu}g/ml) and L.(L.) chagasi (0.63 ({mu}g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC{sub 50} of 11|{mu}g/ml. Irradiation of LAO with 6{sup 0C}o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC{sub 50} of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  9. Arrabidaea chica Hexanic Extract Induces Mitochondrion Damage and Peptidase Inhibition on Leishmania spp.

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    Igor A. Rodrigues

    2014-01-01

    Full Text Available Currently available leishmaniasis treatments are limited due to severe side effects. Arrabidaea chica is a medicinal plant used in Brazil against several diseases. In this study, we investigated the effects of 5 fractions obtained from the crude hexanic extract of A. chica against Leishmania amazonensis and L. infantum, as well as on the interaction of these parasites with host cells. Promastigotes were treated with several concentrations of the fractions obtained from A. chica for determination of their minimum inhibitory concentration (MIC. In addition, the effect of the most active fraction (B2 on parasite’s ultrastructure was analyzed by transmission electron microscopy. To evaluate the inhibitory activity of B2 fraction on Leishmania peptidases, parasites lysates were treated with the inhibitory and subinhibitory concentrations of the B2 fraction. The minimum inhibitory concentration of B2 fraction was 37.2 and 18.6 μg/mL for L. amazonensis and L. infantum, respectively. Important ultrastructural alterations as mitochondrial swelling with loss of matrix content and the presence of vesicles inside this organelle were observed in treated parasites. Moreover, B2 fraction was able to completely inhibit the peptidase activity of promastigotes at pH 5.5. The results presented here further support the use of A. chica as an interesting source of antileishmanial agents.

  10. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with 60Co gamma rays, in Leishmania spp

    International Nuclear Information System (INIS)

    Cardoso, Andre Gustavo Tempone

    1999-01-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 μg/ml (EC 50 ), L.(V.) panamensis (0.78 |μg/ml) and L.(L.) chagasi (0.63 (μg/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC 50 of 11|μg/ml. Irradiation of LAO with 6 0C o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC 50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  11. Studies on the relationship between lectin binding carbohydrates and different strains of Leishmania from the New World

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    J. Schottelius

    1982-03-01

    Full Text Available The culture forms of L. mexicana pifanoi (LRC L-90, L. mexicana mexicana (LRC L-94, M-379; L. braziliensis braziliensis (LRC L-77, L-1, M-2903, H-LSS and L. mexicana amazonensis (H-JMMO, M-JOF, H-21, H-PLL,M-1696 were tested with the following lectins: Canavalia ensiformis, Ricinus communis-120, Axinella polypoides, Phaseolus vulgaris, Evonymus europaeus, lotus tetragonolobus, Dolichos biflorus, Aaptos papillata II, Laburnum alpinum, Ulex europaeus, Arachis hypogaea and Soja hispida. All examined strains of Leishmania were agglutinated by C. ensiformis, R. communis-120 and A. popypoides. No agglutination reactions were observed with P. vulgaris, D.biflorus, A. papillata II, E. europaeus and L. tetragonolobus. Only L. m. pifanoi and the L. m. amazonensis strains H-JMMO and MJOF showed agglutination reactions with S. hispida, U. europaeus, L. alpinum and A. hypogaea, while L. m. mexicana (LRC L-94; M-379 strains, L. b. braziliensis H. LSS, LRC L-77; L-1; M-2903 and the L. m. amazonensis strains, H-PLL, H-21, M-1696 showed no agglutination reactions with these four lectins.

  12. Inaccuracy of Enzyme-Linked Immunosorbent Assay Using Soluble and Recombinant Antigens to Detect Asymptomatic Infection by Leishmania infantum

    Science.gov (United States)

    Moreno, Elizabeth Castro; Gonçalves, Andréa Vieira; Chaves, Anderson Vieira; Melo, Maria Norma; Lambertucci, José Roberto; Andrade, Antero Silva Ribeiro; Negrão-Corrêa, Deborah; Antunes, Carlos Mauricio de Figueiredo; Carneiro, Mariângela

    2009-01-01

    Background One of the most important drawbacks in visceral leishmaniasis (VL) population studies is the difficulty of diagnosing asymptomatic carriers. The aim of this study, conducted in an urban area in the Southeast of Brazil, was to evaluate the performance of serology to identify asymptomatic VL infection in participants selected from a cohort with a two-year follow-up period. Methodology Blood samples were collected in 2001 from 136 cohort participants (97 positive and 39 negatives, PCR/hybridization carried out in 1999). They were clinically evaluated and none had progressed to disease from their asymptomatic state. As controls, blood samples from 22 control individuals and 8 patients with kala-azar were collected. Two molecular biology techniques (reference tests) were performed: PCR with Leishmania-generic primer followed by hybridization using L. infantum probe, and PCR with specific primer to L. donovani complex. Plasma samples were tested by ELISA using three different antigens: L. infantum and L. amazonensis crude antigens, and rK39 recombinant protein. Accuracy of the serological tests was evaluated using sensitivity, specificity, likelihood ratio and ROC curve. Findings The presence of Leishmania was confirmed, by molecular techniques, in all kala-azar patients and in 117 (86%) of the 136 cohort participants. Kala-azar patients showed high reactivity in ELISAs, whereas asymptomatic individuals presented low reactivity against the antigens tested. When compared to molecular techniques, the L. amazonensis and L. infantum antigens showed higher sensitivity (49.6% and 41.0%, respectively) than rK39 (26.5%); however, the specificity of rK39 was higher (73.7%) than L. amazonensis (52.6%) and L. infantum antigens (36.8%). Moreover, there was low agreement among the different antigens used (kappa<0.10). Conclusions Serological tests were inaccurate for diagnosing asymptomatic infections compared to molecular methods; this could lead to misclassification bias

  13. Monitoring the response of patients with cutaneous leishmaniasis to treatment with pentamidine isethionate by quantitative real-time PCR, and identification of Leishmania parasites not responding to therapy.

    Science.gov (United States)

    Mans, D R A; Kent, A D; Hu, R V; Lai A Fat, E J; Schoone, G J; Adams, E R; Rood, E J; Alba, S; Sabajo, L O A; Lai A Fat, R F; de Vries, H J C; Schallig, H D F H

    2016-08-01

    Leishmania (Viannia) guyanensis is believed to be the principal cause of cutaneous leishmaniasis (CL) in Suriname. This disease is treated with pentamidine isethionate (PI), but treatment failure has increasingly been reported. To evaluate PI for its clinical efficacy, to compare parasite load, and to assess the possibility of treatment failure due to other infecting Leishmania species. Parasite load of patients with CL was determined in skin biopsies using real-time quantitative PCR before treatment and 6 and 12 weeks after treatment. Clinical responses were evaluated at week 12 and compared with parasite load. In parallel, molecular species differentiation was performed. L. (V.) guyanensis was the main infecting species in 129 of 143 patients (about 90%). PI treatment led to a significant decrease (P Leishmania (Viannia) braziliensis, Leishmania (Leishmania) amazonensis and L. (V.) guyanensis (1/92, 1/92 and 22/92 evaluable cases, respectively). There was substantial agreement beyond chance between the parasite load at week 6 and the clinical outcome at week 12, as indicated by the κ value of 0.61. L. (V.) guyanensis is the main infecting species of CL in Suriname, followed by L. (V.) braziliensis and L. (L.) amazonensis. Furthermore, patient response to PI can be better anticipated based on the parasite load 6 weeks after the treatment rather than on parasite load before treatment. © 2015 The Authors Clinical and Experimental Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists, North American Clinical Dermatologic Society and St Johns Dermatological Society.

  14. Leishmania mexicana amazonensis: heterogeneity in 5-nucleotidase and peroxidase activities of mononuclear phagocytes during in vivo and in vitro infection Leishmania mexicana amazonensis: heterogeneidade da 5’-Nucleotidase e da peroxidase em fagócitos mononucleares durante infecção in vivo e in vitro

    OpenAIRE

    Suzana Côrte-Real; Gabriel Grimaldi Junior; Maria de Nazareth Leal de Meirelles

    1988-01-01

    The degree of maturation of cells of the Mononuclear Phagocyte System (MPS), during in vivo and in vitro infection by Leishmania mexicana amazonenesis, was evaluated in this study. The macrophages' differentiation was assayed by cytochemical characterization at the ultrastrctural level, using two well-established markers: 5'-nucleotidase enzyme activity, for revealing the mature cells, and the peroxidase activity present in the cell granules to demonstrate immature mononuclear phagocytes. onl...

  15. Quantificação da IL-10 e do INF-γ em cães com ou sem sinais clínicos de infecção com Leishmania (Leishmania chagasi

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    Carla J.R.M. do Rosário

    Full Text Available RESUMO: As leishmanioses compreendem um complexo de doenças causadas por parasitos intracelulares obrigatórios pertencentes ao gênero Leishmania. Consideradas como importante problema de saúde pública, sendo os cães domésticos os principais responsáveis pela manutenção da cadeia epidemiológica da doença, estima-se que mais da metade dos cães infectados não manifestam sinais clínicos da enfermidade. Avaliou-se o perfil de IL-10 e INF- γ de cães naturalmente infectados com Leishmania (Leishmania chagasi no município de São Luís-MA. Foram coletadas 50 amostras, sendo 20 de animais positivos e sintomáticos para Leishmaniose Visceral Canina (LVC, 20 de animais positivos e assintomáticos e 10 de animais sabidamente negativos para a LVC. As amostras foram analisadas pelo teste imunocromatográfico rápido Dual Path Platform (DPP/Biomanguinhos® e pelo ELISA (EIE/Biomanguinhos® indireto para detecção de anticorpos anti-Leishmania. Após as confirmações dos testes, foi realizado o ELISA de captura para quantificação das citocinas IL-10 e INF-γ através do kit Milliplex MAP. Houve diferença estatística entre os grupos, observando um aumento de IL-10 em soros de cães sintomáticos para LVC, comparado com o grupo de animais assintomáticos, sugerindo que animais com essa expressão de IL-10 podem estar associados à susceptibilidade a doença. Assim como o aumento dos níveis de INF-γ observados em cães assintomáticos, comparado com o grupo de cães sintomáticos, poderiam estar relacionados à cronicidade da doença.

  16. Structurally optimized analogs of the retrograde trafficking inhibitor Retro-2cycl limit Leishmania infections.

    Science.gov (United States)

    Craig, Evan; Huyghues-Despointes, Charles-Eugene; Yu, Chun; Handy, Emma L; Sello, Jason K; Kima, Peter E

    2017-05-01

    In infected mammalian cells, Leishmania parasites reside within specialized compartments called parasitophorous vacuoles (LPVs). We have previously shown that Retro-2, a member of a novel class of small retrograde pathway inhibitors caused reduced LPV sizes and lower parasite numbers during experimental L. mexicana sp. infections. The purpose of this study was to determine if structural analogs of Retro-2cycl reported to have superior potency in the inhibition of retrograde pathway-dependent phenomena (i.e., polyomavirus cellular infection by polyomavrius and Shiga toxin trafficking in cells) are also more effective than the parent compound at controlling Leishmania infections. In addition to their effects on LPV development, we show that two optimized analogs of Retro-2cycl, DHQZ 36 and DHQZ 36.1 limit Leishmania amazonensis infection in macrophages at EC50 of 13.63+/-2.58μM and10.57+/-2.66μM, respectively, which is significantly lower than 40.15μM the EC50 of Retro-2cycl. In addition, these analogs caused a reversal in Leishmania induced suppression of IL-6 release by infected cells after LPS activation. Moreover, we show that in contrast to Retro-2cycl that is Leishmania static, the analogs can kill Leishmania parasites in axenic cultures, which is a desirable attribute for any drug to treat Leishmania infections. Together, these studies validate and extend the published structure-activity relationship analyses of Retro-2cycl.

  17. Anti-Leishmania activity of new ruthenium(II) complexes: Effect on parasite-host interaction.

    Science.gov (United States)

    Costa, Mônica S; Gonçalves, Yasmim G; Nunes, Débora C O; Napolitano, Danielle R; Maia, Pedro I S; Rodrigues, Renata S; Rodrigues, Veridiana M; Von Poelhsitz, Gustavo; Yoneyama, Kelly A G

    2017-10-01

    Leishmaniasis is a parasitic disease caused by protozoa of the genus Leishmania. The many complications presented by the current treatment - including high toxicity, high cost and parasite resistance - make the development of new therapeutic agents indispensable. The present study aims to evaluate the anti-Leishmania potential of new ruthenium(II) complexes, cis‑[Ru II (η 2 -O 2 CR)(dppm) 2 ]PF 6 , with dppm=bis(diphenylphosphino)methane and R=4-butylbenzoate (bbato) 1, 4-(methylthio)benzoate (mtbato) 2 and 3-hydroxy-4-methoxybenzoate (hmxbato) 3, in promastigote cytotoxicity and their effect on parasite-host interaction. The cytotoxicity of complexes was analyzed by MTT assay against Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Leishmania) infantum promastigotes and the murine macrophage (RAW 264.7). The effect of complexes on parasite-host interaction was evaluated by in vitro infectivity assay performed in the presence of two different concentrations of each complex: the promastigote IC 50 value and the concentration nontoxic to 90% of RAW 264.7 macrophages. Complexes 1-3 exhibited potent cytotoxic activity against all Leishmania species assayed. The IC 50 values ranged from 7.52-12.59μM (complex 1); 0.70-3.28μM (complex 2) and 0.52-1.75μM (complex 3). All complexes significantly inhibited the infectivity index at both tested concentrations. The infectivity inhibitions ranged from 37 to 85%. Interestingly, the infectivity inhibitions due to complex action did not differ significantly at either of the tested concentrations, except for the complex 1 against Leishmania (Leishmania) infantum. The infectivity inhibitions resulted from reductions in both percentage of infected macrophages and number of parasites per macrophage. Taken together the results suggest remarkable leishmanicidal activity in vitro by these new ruthenium(II) complexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Evaluation of HIV-Leishmania co-infection in patients from the northwestern Paraná State, Brazil = Avaliação da co-infecção HIV-Leishmania em pacientes da região noroeste do Estado do Paraná, Brasil

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    Élide Aparecida Oliveira

    2011-01-01

    Full Text Available Leishmaniasis occurs throughout the world and is one of the opportunistic infections that attack HIV-infected individuals. Few data are available on American cutaneous leishmaniasis (ACL in HIV-infected patients. Current research investigates the occurrence ofHIV-Leishmania co-infection in HIV-infected individuals in an endemic region in Southern of Brazil. A non-randomized transversal investigation, molecular and serum epidemiologic type, on the occurrence of ACL in 169 HIV-infected patients was undertaken. The patients were followed up at the Integrated Nucleus of Health of the city Maringá, Southern of Brazil. Results showed that 13 (7.7% of the HIV-infected patients also presented Leishmania (Viannia DNA, detectable in blood by PCR. Serology, direct research, culture and PCR in skin material produced negative results. PCR positiveness for Leishmania was not associated with CD4 T lymphocytes count, opportunistic disease, treatment, use of proteases inhibitors, tattooing/piercing or use of injectable drugs, residential environment or previous ACL history. Results show that HIVinfected patients who live in endemic areas may reveal Leishmania DNA in the blood without any ACL symptoms. Above findings may be attributed to anti-retrovirus medicine that controls viral replication and maintains the functionality of the immune system and to a possible anti- Leishmania activity of these drugs.As leishmanioses ocorrem em todo o mundo e são infecções oportunistas que afetam indivíduos portadores do vírus HIV. Este estudo investigou a ocorrência da co-infecção HIV-Leishmania em portadores do HIV numa região endêmica para LTA do Sul do Brasil. Foi realizado estudo transversal, não randomizado, utilizando metodologia molecular e sorológica, sobre a ocorrência de LTA em 169 portadores do HIV. Foram estudados pacientes atendidos no Núcleo Integrado de Saúde de Maringá, Paraná, Sul do Brasil. Observou-se que 13 (7,7% dos pacientes infectados

  19. Papel de la vacuola parasitófora de macrófagos de ratón infectados por Leishmania amazonensis en la adquisición de moléculas

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    Tania M. Cortázar

    2006-10-01

    Full Text Available Introducción. Leishmania son parásitos intracelulares de macrófagos, confinados encompartimentos denominados vacuolas parasitóforas. La permeabilidad de este compartimentodepende de su interacción con el tráfico vesicular y transportadores presentes en su membrana. Objetivo. En este trabajo se estudió la permeabilidad de la membrana de la vacuola parasitóforaen la línea celular J774.A1 infectada con Leishmania amazonensis, in situ y en compartimentosaislados. Materiales y métodos. El aislamiento de vacuolas parasitóforas se hizo por gradiente dedensidad. La permeabilidad de la membrana de estas se valoró por distribución de sondasfluorescentes y electrofisiología. Para establecer indirectamente el transporte de protones seusó naranja de acridina. La presencia de transportadores ABC sensibles a probenecid seestableció con amarillo lucifer y calceína. Por primera vez con la técnica de patch-clamp seregistraron corrientes en la membrana de este compartimento aislado. Resultados. La vacuola parasitófora colorea de rojo con naranja de acridina indicando un pHácido. Concentra amarillo lucifer a través de un transportador sensible a probenecid, peroexcluye la sonda calceína. Vacuolas aisladas se marcan de rojo con naranja de acridina yconcentran amarillo lucifer a través de un transportador sensible a probenecid. Estas vacuolasexcluyeron calceína y presentaron en su membrana una corriente iónica que se activa adiferencias de potencial cercanas a 60 mV, con una conductancia de 46 ± 3 pS. Conclusiones. Se pueden aislar vacuolas parasitóforas con propiedades de permeabilidadque preservan mecanismos de transporte similares a los encontrados in situ. Se registra porprimera vez la presencia de una corriente iónica poco selectiva en la membrana de estecompartimiento.

  20. AVALIAÇÃO DA TERAPIA FOTODINÂMICA COM AZUL DE METILENO EM Leishmania major e Leishmania braziliensis: ESTUDO in vitro

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    Danielle El Atra Coelho

    2017-03-01

    Full Text Available A Leishmaníase é uma doença crônica causada pelo protozoário do gênero Leishmania, cujo tratamento é agressivo. A Terapia Fotodinâmica (TFD é uma alternativa promissora que combina luz, fotossensibilizador (FS e oxigênio molecular, para causar a morte celular. O objetivo desse trabalho foi avaliar, in vitro, a ação da TFD com Azul de metileno (AM em promastigotas de Leishmania, por teste de MTT, curva de crescimento e morfologia do parasito. O teste de MTT demonstrou alteração de ambas as espécies após interação com o AM no escuro e após TFD. A análise das curvas demonstrou que a TFD influenciou o crescimento das espécies. A análise morfológica revelou que o AM no escuro não causou alterações expressivas como a TFD, sendo a cepa de L. braziliensis mais afetada que a cepa de L. major. Pode-se concluir que a TFD com AM foi promissora contra promastigotas de Leishmania, pois foi capaz de diminuir o crescimento e alterar a morfologia dos parasitos em cultura.

  1. Leishmania isoenzyme polymorphisms in Ecuador: Relationships with geographic distribution and clinical presentation

    Science.gov (United States)

    Calvopina, Manuel; Armijos, Rodrigo X; Marco, Jorge D; Uezato, Hiroshi; Kato, Hirotomo; Gomez, Eduardo A; Korenaga, Masataka; Barroso, Paola A; Mimori, Tatsuyuki; Cooper, Philip J; Nonaka, Shigeo; Hashiguchi, Yoshihisa

    2006-01-01

    Background Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed. Methods Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador. PMID:16968553

  2. Total Leishmania antigens with Poly(I:C) induce Th1 protective response.

    Science.gov (United States)

    Sanchez, M V; Eliçabe, R J; Di Genaro, M S; Germanó, M J; Gea, S; García Bustos, M F; Salomón, M C; Scodeller, E A; Cargnelutti, D E

    2017-11-01

    Our proposal was to develop a vaccine based on total Leishmania antigens (TLA) adjuvanted with polyinosinic-polycytidylic acid [Poly(I:C)] able to induce a Th1 response which can provide protection against Leishmania infection. Mice were vaccinated with two doses of TLA-Poly(I:C) administered by subcutaneous route at 3-week interval. Humoral and cellular immune responses induced by the immunization were measured. The protective efficacy of the vaccine was evaluated by challenging mice with infective promastigotes of Leishmania (Leishmania) amazonensis into the footpad. Mice vaccinated with TLA-Poly(I:C) showed a high anti-Leishmania IgG titre, as well as increased IgG1 and IgG2a subclass titres compared with mice vaccinated with the TLA alone. The high IgG2a indicated a Th1 bias response induced by the TLA-Poly(I:C) immunization. Accordingly, the cellular immune response elicited by the formulation was characterized by an increased production of IFN-γ and no significant production of IL-4. The TLA-Poly(I:C) immunization elicited good protection, which was associated with decreased footpad swelling, a lower parasite load and a reduced histopathological alteration in the footpad. Our findings demonstrate a promising vaccine against cutaneous leishmaniasis that is relatively economic and easy to develop and which should be taken into account for preventing leishmaniasis in developing countries. © 2017 John Wiley & Sons Ltd.

  3. Suppression of LPS-induced inflammatory responses in macrophages infected with Leishmania

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    Kelly Ben L

    2010-02-01

    Full Text Available Abstract Background Chronic inflammation activated by macrophage innate pathogen recognition receptors such as TLR4 can lead to a range of inflammatory diseases, including atherosclerosis, Crohn's disease, arthritis and cancer. Unlike many microbes, the kinetoplastid protozoan pathogen Leishmania has been shown to avoid and even actively suppress host inflammatory cytokine responses, such as LPS-induced IL-12 production. The nature and scope of Leishmania-mediated inflammatory cytokine suppression, however, is not well characterized. Advancing our knowledge of such microbe-mediated cytokine suppression may provide new avenues for therapeutic intervention in inflammatory disease. Methods We explored the kinetics of a range of cytokine and chemokine responses in primary murine macrophages stimulated with LPS in the presence versus absence of two clinically distinct species of Leishmania using sensitive multiplex cytokine analyses. To confirm that these effects were parasite-specific, we compared the effects of Leishmania uptake on LPS-induced cytokine expression with uptake of inert latex beads. Results Whilst Leishmania uptake alone did not induce significant levels of any cytokine analysed in this study, Leishmania uptake in the presence of LPS caused parasite-specific suppression of certain LPS-induced pro-inflammatory cytokines, including IL-12, IL-17 and IL-6. Interestingly, L. amazonensis was generally more suppressive than L. major. We also found that other LPS-induced proinflammatory cytokines, such as IL-1α, TNF-α and the chemokines MIP-1α and MCP-1 and also the anti-inflammatory cytokine IL-10, were augmented during Leishmania uptake, in a parasite-specific manner. Conclusions During uptake by macrophages, Leishmania evades the activation of a broad range of cytokines and chemokines. Further, in the presence of a strong inflammatory stimulus, Leishmania suppresses certain proinflammatory cytokine responses in a parasite

  4. Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae: Phlebotominae) in the Lençóis Maranhenses National Park, Brazil.

    Science.gov (United States)

    Pereira-Filho, Adalberto Alves; Fonteles, Raquel Silva; Bandeira, Maria da Conceição Abreu; Moraes, Jorge Luiz Pinto; Rebêlo, José Manuel Macário; Melo, Maria Norma

    2018-02-20

    Sand flies are very common in the region of Lençóis Maranhenses National Park, an important tourist attraction in Brazil. However, the role of some species and their relative importance locally in Leishmania Ross 1903 transmission is unclear. The objective of this study was to identify Leishmania infection in phlebotomine sand flies collected around the Lençóis Maranhenses National Park, an important conservation area and popular international/national tourist destination with a high incidence of leishmaniasis. Sand flies were collected in peridomiciliary areas on the tourist route from September 2012 to August 2013. The captured females were subjected to molecular analyses for the detection of Leishmania DNA. Sand flies were infected with four Leishmania species: Leishmania (Viannia) braziliensis (Vianna, 1911) was found in Lutzomyia whitmani (Antunes and Coutinho, 1939) (2.1%) and Lutzomyia longipalpis (Lutz and Neiva, 1912) (1.7%); Leishmania (Leishmania) infantum (Nicole, 1908) infected Lutzomyia wellcomei (Fraiha, Shaw, and Lainson, 1971) (20%), Lutzomyia sordellii (Shannon and Del Ponte, 1927) (4.3%), Lu. longipalpis (3.7%), and Lu. whitmani (0.8%); Leishmania (Leishmania) amazonensis (Lainson & Shaw, 1972) was found in Lu. whitmani (0.58%), while Leishmania (Viannia) lainsoni infected Lutzomyia evandroi (Costa Lima and Antunes, 1936) (3.4%), Lu. longipalpis (1.06%), and Lu. whitmani (0.29%). The occurrence of these parasites requires control measures to reduce the incidence of cutaneous leishmaniasis and to contain a possible epidemic of visceral leishmaniasis, the most severe form of the disease.

  5. Ensayos metodologicos para la investigacion de reservorios de Leishmania spp en los Andes venezolanos Methodological assay for research of reservoirs of Leishmania spp. in the Venezuelan Andes

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    Ana Lugo Yarbuh

    1982-12-01

    Full Text Available Se describen dos técnicas, presuntiva y confirmativa, para la investigación de mamíferos que pudieran ser reservorios de Leishmania que parasitan al hombre. Se investigan los cambios en los títulos de inmovilización y aglutinación de promastigotos de cultivo por los sueros de animales normales y expuestos una o varias veces a la inoculación intradérmica de pequeñas dosis de promastigotos vivos. Se registra una caída de los títulos de aglutinación en los sueros de hamsteres, de Holochilus venezuelae y de Didelphis marsupialis después de la inoculación con L. mexicana mexicana de Panamá y de L. gamhami de la región de los Andes venezolanos. Se discute la natureza de estos fenómenos. Se han hecho xenodiagnósticos con Lutzomyia townsendi en Holochilus venezuelae y Sigmodon hispidus infectados experimentalmente com L. mexicana mexicana, L. mexicana amazonensis, L. braziliensis y L. garnhami. Las pruebas fueron leidas mediante el examen microscópico de las gotitas de heces excretadas entre las 108 y 132 horas después de la ingesta infectante, tras colorearlas con Giemsa. Se obtuvieron resultados positivos en 23% de los experimentos usando mamíferos con lesiones localizadas, dejando a los flebótomos ingurgitarse libremente sobre animales anestesiados que poseian una hasta varias lesiones localizadas.Presumptive and confirmative techniques for searching mammals which could be reservoirs for Leishmania parasites from man are described. The changes of immobilising and agglutinating titers for promastigotes from culture by sera from normal and exposed mammals after single or repeated intradermal inoculation of promastigotes are described. A fall in titers of agglunation is observed in sera from hamsters, Holochilus venezuelae and Didelphis marsupialis after inoculation with L. mexicana mexicana from Panama and L. garnhami from the Venezuelan Andes region. The nature of this phenomenon is discussed. Xenodiagnoses were made with

  6. Leishmania isoenzyme polymorphisms in Ecuador: Relationships with geographic distribution and clinical presentation

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    Mimori Tatsuyuki

    2006-09-01

    Full Text Available Abstract Background Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL from Ecuador were analyzed. Methods Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia panamensis (21 isolates, 7 zymodemes, L. (V. guyanensis (7 isolates, 4 zymodemes, L. (V. braziliensis (5 isolates, 3 zymodemes, L. (Leishmania mexicana (11 isolates, 4 zymodemes, L. (L. amazonensis (10 isolates, 2 zymodemes and L. (L. major (2 isolates, 1 zymodeme. L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL; eight cases of leishmaniasis recidiva cutis (LRC found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador.

  7. Real-time PCR for Leishmania species identification: Evaluation and comparison with classical techniques.

    Science.gov (United States)

    de Morais, Rayana Carla Silva; da Costa Oliveira, Cintia Nascimento; de Albuquerque, Suênia da Cunha Gonçalves; Mendonça Trajano Silva, Lays Adrianne; Pessoa-E-Silva, Rômulo; Alves da Cruz, Heidi Lacerda; de Brito, Maria Edileuza Felinto; de Paiva Cavalcanti, Milena

    2016-06-01

    Cutaneous leishmaniasis (CL) is a parasitic disease caused by various Leishmania species. Several studies have shown that real time quantitative PCR (qPCR) can be used for Leishmania spp. identification by analyzing the melting temperature (Tm). Thus, the aim of this study was to evaluate the viability of qPCR for differentiating eight closely related Leishmania species that cause the same clinical form of the disease and to compare the results with classical techniques. qPCR assays for standardizing the Tm using reference strains were performed. After the CL diagnosis on blood samples of domestic animals, positive samples were analyzed by their Tm and qPCR products were purified and sequenced. Ten human samples previously characterized by Multilocus Enzyme Electrophoresis (MLEE) were also analyzed by Tm. A Restriction Fragment Length Polymorphism (RFLP) assay, a reference test, was also standardized, by using the reference strains. Through standardization of Tm for Leishmania spp., two Tm ranges were created for analysis: 1 (Tm = 78-79.99 °C) included Leishmania (V.) braziliensis, Leishmania (V.) panamensis, Leishmania (V.) lainsoni, Leishmania (V.) guyanensis and Leishmania (V.) shawi; and 2 (Tm = 80-82.2 °C) included Leishmania (V.) naiffi, Leishmania (L.) amazonensis and Leishmania (L.) mexicana. A total of 223 positive blood samples were analyzed, with 58 included in range 1 and 165 in range 2. L. (V.) braziliensis, L. (V.) panamensis and L. (V.) guyanensis were identified by sequencing, while L. (V.) braziliensis, L. (L.) mexicana and L. (V.) panamensis were identified by RFLP analysis. Ten human samples previously characterized by Multilocus Enzyme Electrophoresis (MLEE) were also analyzed by qPCR Tm analysis; five were classified in range 1 and five in range 2. A concordance of 80% was calculated between qPCR and the gold-standard (MLEE) with no significant difference between the methods (p = 0.6499); a similar result was observed for sequencing

  8. Arginine and Polyamines Fate in Leishmania Infection

    Science.gov (United States)

    Muxel, Sandra M.; Aoki, Juliana I.; Fernandes, Juliane C. R.; Laranjeira-Silva, Maria F.; Zampieri, Ricardo A.; Acuña, Stephanie M.; Müller, Karl E.; Vanderlinde, Rubia H.; Floeter-Winter, Lucile M.

    2018-01-01

    Leishmania is a protozoan parasite that alternates its life cycle between the sand fly and the mammalian host macrophages, involving several environmental changes. The parasite responds to these changes by promoting a rapid metabolic adaptation through cellular signaling modifications that lead to transcriptional and post-transcriptional gene expression regulation and morphological modifications. Molecular approaches such as gene expression regulation, next-generation sequencing (NGS), microRNA (miRNA) expression profiling, in cell Western blot analyses and enzymatic activity profiling, have been used to characterize the infection of murine BALB/c and C57BL/6 macrophages, as well as the human monocytic cell-lineage THP-1, with Leishmania amazonensis wild type (La-WT) or arginase knockout (La-arg-). These models are being used to elucidate physiological roles of arginine and polyamines pathways and the importance of arginase for the establishment of the infection. In this review, we will describe the main aspects of Leishmania-host interaction, focusing on the arginine and polyamines pathways and pointing to possible targets to be used for prognosis and/or in the control of the infection. The parasite enzymes, arginase and nitric oxide synthase-like, have essential roles in the parasite survival and in the maintenance of infection. On the other hand, in mammalian macrophages, defense mechanisms are activated inducing alterations in the mRNA, miRNA and enzymatic profiles that lead to the control of infection. Furthermore, the genetic background of both parasite and host are also important to define the fate of infection. PMID:29379478

  9. Synthesis, Leishmanicidal Activity and Theoretical Evaluations of a Series of Substituted bis-2-Hydroxy-1,4-Naphthoquinones

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    Morgana V. de Araújo

    2014-09-01

    Full Text Available A series of eight substituted bis-2-hydroxy-1,4-naphthoquinone derivatives was synthesized through lawsone condensation with various aromatic and aliphatic aldehydes under mild acidic conditions. The title compounds were evaluated for antileishmanial activity in vitro against Leishmania amazonensis and Leishmania braziliensis promastigotes; six compounds showed good activity without significant toxic effects. The compound with the highest activity was used for an in vivo assay with Leishmania amazonensis.

  10. Occurrence of Leishmania (Leishmania chagasi in a domestic cat (Felis catus in Andradina, São Paulo, Brazil: case report Ocorrência de Leishmania (Leishmania chagasi em gato doméstico (Felis catus em Andradina, São Paulo, Brasil: relato de caso

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    Willian Marinho Dourado Coelho

    2010-12-01

    Full Text Available This work describes natural infection by Leishmania in a domestic cat where amastigote forms of the parasite were observed in the popliteal lymph node imprint. Positive and negative serological reactions were observed by enzyme-linked immunosorbent assay (ELISA and indirect immunofluorescence assay (IFA, respectively. Polymerase chain reaction (PCR revealed that the nucleotide sequence of the sample was identical to Leishmania (L. chagasi. This is the first report of the disease in felines of the city of Andradina, SP, an area considered endemic for canine and human visceral leishmaniasis.Neste trabalho, é relatada a infecção natural por Leishmania em um gato doméstico no qual, formas amastigotas do parasito foram observadas em imprint de linfonodo poplíteo. Reações sorológicas positivas e negativas foram observadas pelo teste de imunoadsorção enzimática (ELISA e reação de imunofluorescência indireta (RIFI, respectivamente. A reação em cadeia da polimerase (PCR revelou que a sequência de nucleotídeos foi idêntica à Leishmania (L. chagasi. Este é o primeiro relato da doença em felino da cidade de Andradina, Estado de São Paulo, Brasil, área considerada endêmica para leishmaniose visceral canina e humana.

  11. Modulation of Na+/K+ ATPase Activity by Hydrogen Peroxide Generated through Heme in L. amazonensis.

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    Nathália Rocco-Machado

    Full Text Available Leishmania amazonensis is a protozoan parasite that occurs in many areas of Brazil and causes skin lesions. Using this parasite, our group showed the activation of Na+/K+ ATPase through a signaling cascade that involves the presence of heme and protein kinase C (PKC activity. Heme is an important biomolecule that has pro-oxidant activity and signaling capacity. Reactive oxygen species (ROS can act as second messengers, which are required in various signaling cascades. Our goal in this work is to investigate the role of hydrogen peroxide (H2O2 generated in the presence of heme in the Na+/K+ ATPase activity of L. amazonensis. Our results show that increasing concentrations of heme stimulates the production of H2O2 in a dose-dependent manner until a concentration of 2.5 μM heme. To confirm that the effect of heme on the Na+/K+ ATPase is through the generation of H2O2, we measured enzyme activity using increasing concentrations of H2O2 and, as expected, the activity increased in a dose-dependent manner until a concentration of 0.1 μM H2O2. To investigate the role of PKC in this signaling pathway, we observed the production of H2O2 in the presence of its activator phorbol 12-myristate 13-acetate (PMA and its inhibitor calphostin C. Both showed no effect on the generation of H2O2. Furthermore, we found that PKC activity is increased in the presence of H2O2, and that in the presence of calphostin C, H2O2 is unable to activate the Na+/K+ ATPase. 100 μM of Mito-TEMPO was capable of abolishing the stimulatory effect of heme on Na+/K+ ATPase activity, indicating that mitochondria might be the source of the hydrogen peroxide production induced by heme. The modulation of L. amazonensis Na+/K+ ATPase by H2O2 opens new possibilities for understanding the signaling pathways of this parasite.

  12. Fauna de flebotomíneos (Diptera: Psychodidae em um foco de leishmaniose tegumentar americana na área periurbana de Manaus, Estado do Amazonas Sandfly fauna (Diptera: Psychodidae in a focus of American cutaneous leishmaniasis on the urban periphery of Manaus, State of Amazonas

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    Maria das Graças Vale Barbosa

    2008-10-01

    Full Text Available No período de agosto de 2001 a julho de 2002, usando armadilhas CDC e Disney, realizaram-se coletas de flebotomíneos, na base de árvores no peridomicílio e nas matas da Comunidade São João, área periurbana de Manaus, Amazonas. Foram capturados 4.104 espécimes, pertencentes a quatro subtribos, 13 gêneros e 49 espécies da subfamília Phlebotominae. Predominou a subtribo Psychodopygina com 3.403 (83% espécimes, destacando-se Nyssomyia umbratilis, Nyssomyia anduzei, Trichophoromyia eurypyga, Bichromomyia olmeca nociva e Bichromomyia flaviscutellata. O registro de Nyssomyia umbratilis e Nyssomyia anduzei, incriminadas como vetoras de Leishmania (Viannia guyanensis, e de Bichromomyia flaviscutellata e Bichromomyia olmeca nociva, de Leishmania (Leishmania amazonensis, indicam risco de infecção para os moradores da área. A grande maioria (98,5% dos flebotomíneos foi capturada na área de mata. Nyssomyia anduzei e Bichromomyia olmeca nociva foram coletadas no peridomicílio. A riqueza de espécies vetoras de Leishmania nessa área revela a necessidade de uma vigilância entomológica constante.From August 2001 to July 2002, sand flies were collected from the bases of trees and, using CDC and Disney traps, from areas surrounding homes and forested areas in the São João community, on the urban periphery of Manaus, State of Amazonas. 4,104 specimens belonging to four subtribes, 13 genera and 49 species of the Phlebotominae subfamily were collected. The subtribe Psychodopygina predominated, with 3,403 (83% specimens, especially of Nyssomyia umbratilis, Nyssomyia anduzei, Trichophoromyia eurypyga, Bichromomyia olmeca nociva and Bichromomyia flaviscutellata. The occurrences of Nyssomyia umbratilis and Nyssomyia anduzei, which have been incriminated as vectors for Leishmania (Viannia guyanensis, and of Bichromomyia flaviscutellata and Bichromomyia olmeca nociva, for Leishmania (Leishmania amazonensis, indicate that there is a risk of infection

  13. Syzygium cumini (L.) Skeels essential oil and its major constituent α-pinene exhibit anti-Leishmania activity through immunomodulation in vitro.

    Science.gov (United States)

    Rodrigues, Klinger Antonio da Franca; Amorim, Layane Valéria; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

    2015-02-03

    Syzygium cumini (L.) Skeels (Myrtaceae), commonly known as "jambolão" in Brazil is widely used in folk medicine against leishmaniasis, inflammation, chronic diarrhea, and ulcers. It is one of the most commonly used plants for the treatment of diabetes worldwide. In previous studies, Syzygium cumini was shown to possess antihyperlipidemic and anti-allergic properties, and to exhibit good performance as an antimicrobial agent against bacteria, fungi, and protozoa parasites of the genus Leishmania and Trypanosoma. This study was aimed at evaluating the effects of S. cumini essential oil (ScEO) and its major component α-pinene on Leishmania (Leishmania) amazonensis, as well as their cytotoxicity and possible mechanisms of action. To evaluate the anti-proliferative effect on Leishmania, effects on promastigote and axenic amastigote forms were assessed using tetrazolium salt (MTT) assay. The intramacrophagic amastigotes were exposed to ScEO and α-pinene to determine the survival index. To gain insight into the mechanism of action involved in the effect on the samples, we evaluated the modulation of macrophage activation state by observing structural (phagocytic and lysosomal activities) and cellular (nitric oxide increase) changes. To assess the safety profile of ScEO and α-pinene, murine macrophages and human red blood cells were treated with ScEO and α-pinene and the selectivity index was calculated for each treatment. α-Pinene was effective against Leishmania amazonensis promastigote forms, with a half-maximal inhibitory concentration (IC50) value of 19.7µg/mL. α-Pinene was more active (IC50 values of 16.1 and 15.6µg/mL against axenic and intracellular amastigotes, respectively) than ScEO (IC50 values of 43.9 and 38.1µg/mL against axenic and intracellular amastigotes, respectively). Our results showed that the anti-Leishmania effects were mediated by immunomodulatory activity, as evidenced by the observed increases in both phagocytic and lysosomal activity

  14. Tentativa de transmissão da Leishmania donovani pela picada do Lutzomyia longipalpis entre cães

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    Ítalo A. Sherlock

    1972-02-01

    Full Text Available Os Autores apresentam dados sôbre tentativas de transmissão experimental da Leishmania donovani pela picada de Lutzomyia longipalpis entre cães. Dois cães jovens sadios foram picados respectivamente por dois e sete flebótomos ricamente infectados e não adquiriram leishmaniose.

  15. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    OpenAIRE

    Rodrigues, Klinger Antonio da Franca; Amorim, Layane Val?ria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando A?cio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components...

  16. High Resolution Melting Analysis Targeting hsp70 as a Fast and Efficient Method for the Discrimination of Leishmania Species.

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    Ricardo Andrade Zampieri

    2016-02-01

    Full Text Available Protozoan parasites of the genus Leishmania cause a large spectrum of clinical manifestations known as Leishmaniases. These diseases are increasingly important public health problems in many countries both within and outside endemic regions. Thus, an accurate differential diagnosis is extremely relevant for understanding epidemiological profiles and for the administration of the best therapeutic protocol.Exploring the High Resolution Melting (HRM dissociation profiles of two amplicons using real time polymerase chain reaction (real-time PCR targeting heat-shock protein 70 coding gene (hsp70 revealed differences that allowed the discrimination of genomic DNA samples of eight Leishmania species found in the Americas, including Leishmania (Leishmania infantum chagasi, L. (L. amazonensis, L. (L. mexicana, L. (Viannia lainsoni, L. (V. braziliensis, L. (V. guyanensis, L. (V. naiffi and L. (V. shawi, and three species found in Eurasia and Africa, including L. (L. tropica, L. (L. donovani and L. (L. major. In addition, we tested DNA samples obtained from standard promastigote culture, naturally infected phlebotomines, experimentally infected mice and clinical human samples to validate the proposed protocol.HRM analysis of hsp70 amplicons is a fast and robust strategy that allowed for the detection and discrimination of all Leishmania species responsible for the Leishmaniases in Brazil and Eurasia/Africa with high sensitivity and accuracy. This method could detect less than one parasite per reaction, even in the presence of host DNA.

  17. High Resolution Melting Analysis Targeting hsp70 as a Fast and Efficient Method for the Discrimination of Leishmania Species.

    Science.gov (United States)

    Zampieri, Ricardo Andrade; Laranjeira-Silva, Maria Fernanda; Muxel, Sandra Marcia; Stocco de Lima, Ana Carolina; Shaw, Jeffrey Jon; Floeter-Winter, Lucile Maria

    2016-02-01

    Protozoan parasites of the genus Leishmania cause a large spectrum of clinical manifestations known as Leishmaniases. These diseases are increasingly important public health problems in many countries both within and outside endemic regions. Thus, an accurate differential diagnosis is extremely relevant for understanding epidemiological profiles and for the administration of the best therapeutic protocol. Exploring the High Resolution Melting (HRM) dissociation profiles of two amplicons using real time polymerase chain reaction (real-time PCR) targeting heat-shock protein 70 coding gene (hsp70) revealed differences that allowed the discrimination of genomic DNA samples of eight Leishmania species found in the Americas, including Leishmania (Leishmania) infantum chagasi, L. (L.) amazonensis, L. (L.) mexicana, L. (Viannia) lainsoni, L. (V.) braziliensis, L. (V.) guyanensis, L. (V.) naiffi and L. (V.) shawi, and three species found in Eurasia and Africa, including L. (L.) tropica, L. (L.) donovani and L. (L.) major. In addition, we tested DNA samples obtained from standard promastigote culture, naturally infected phlebotomines, experimentally infected mice and clinical human samples to validate the proposed protocol. HRM analysis of hsp70 amplicons is a fast and robust strategy that allowed for the detection and discrimination of all Leishmania species responsible for the Leishmaniases in Brazil and Eurasia/Africa with high sensitivity and accuracy. This method could detect less than one parasite per reaction, even in the presence of host DNA.

  18. The action of ionizing radiation on the morphology, physiology and growth of Leishmania Amazonensis, with evaluation of their immunogenic power in experimental models; Acao da radiacao ionizante sobre a morfologia, fisiologia e crescimento da Leishmania amazonensis, com avaliacao de seu poder imunogenico em modelos experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Franco Claudio

    2002-07-01

    Leishmaniasis is a disease which affects thousands of people in the Tropical regions around the world, is caused by a protozoan of the genus Leishmania spp., with urban and wild mammals acting as reservoirs. In the mammal host, the amastigote form of the parasite infects and multiplies into macrophages. Treatments for leishmaniasis have a high cost and are long lasting, frequently resulting in therapy interruption. This procedure culminates with a selection of resistant parasite strains, inducing tolerance to the therapy. Either the control of vectors or the mammal host are difficult due the social and economic implications. Thus, the search for alternatives treatments against these protozoans have been stimulated. The gamma radiation ({sup 60}CO) shown to be an efficient toll to kill these parasites maintaining their immunogenicity. Cellular viability, Electronically microscopy and Multiplex-PCR techniques showed that, after irradiation, the parasites had their growth inhibited by cytoplasmatic and nucleic material disorganisation, appointing the gamma radiation as important in terms of immunogens improvement. (author)

  19. Holochilus brasiliensis nanus Thomas, 1897: sugestão de modelo experimental para filariose, leishmaniose e esquistossomose Holochilus brasiliensis nanus Thomas, 1897: as an experimental model for filariasis, leishmaniasis and schistosomiasis

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    Othon de Carvalho Bastos

    1984-12-01

    Full Text Available Roedores silvestres, classificados como Holochilus brasiliensis nanus Thomas,1897, foram capturados na cidade de São Bento, pertencente à Região da Baixada, do Estado do Maranhão, Brasil, naturalmente infectados com formas adultas de filaria, na cavidade peritoneal, e microfilárias sangüíneas, assim como, com esquistossoma mansoni (vermes adultos e granulomas peri-ovulares hepáticos; intestinais; pulmonares; esplênicos e pancreáticos. Animais nascidos em Biotério, descendentes de Holochilus da Região da Baixada, foram infectados experimentalmente com Leishmania m. amazonensis e Schistosoma mansoni. Em observações semanais, foram encontradas lesões teciduais, semelhantes às que se desenvolvem em hamsters infectados com Leishmania, e hipergamaglobulinemia. Nos esquistossomóticos, foram constatadas hipergamaglobulinemia e reações granulomatosas similares às encontradas nos animais infectados naturalmente. Foram observadas, também, lesões hepática graves, semelhantes às encontradas na esquistossomose humana. Estes achados sugerem a utilização do Holochilus b. nanus como modelo experimental destas três doenças tropicais.Wild rodents classified as Holochilus brasiliensis nanus THOMAS, 1897, were captured in Lowland Region of State of Maranhão-Brazil. Natural infection by schistosome and filaria was detected in the most of these animals. Rodents born in the Animal House of the University of Maranhão were experimentally infected with Leishmania mexicana amazonensis or Schistosoma mansoni. Pathological aspects of leishmaniasis in these animals were found similar to that found in hamsters infected with Leishmania. Severe hepatic lesions were found in the animals infected with schistosome similar to that seen in human infection. These findings suggest the utilization of this animal as an experimental model of filariasis, leishmaniasis and schistosomiasis.

  20. 46-kDa protein located in the flagellar pocket of Leishmania ...

    Indian Academy of Sciences (India)

    NII

    Cloning and expression of endocytic Rab GTPases from Leishmania. Fractionation of early compartment from. Leishmania containing endocytic probes. Rab7:WT. Rab5: WT. Localization of Rab5 and Rab7 in Leishmania. Phase. LTR. Merge. Rab7-GFP. Rab5-GFP. LTR. Phase. Merge. Rab5-GFP. Rab7-GFP. Lysosomes.

  1. Use of Recombinant Antigens for Sensitive Serodiagnosis of American Tegumentary Leishmaniasis Caused by Different Leishmania Species.

    Science.gov (United States)

    Sato, Camila Massae; Sanchez, Maria Carmen Arroyo; Celeste, Beatriz Julieta; Duthie, Malcolm S; Guderian, Jeffrey; Reed, Steven G; de Brito, Maria Edileuza Felinto; Campos, Marliane Batista; de Souza Encarnação, Helia Valeria; Guerra, Jorge; de Mesquita, Tirza Gabrielle Ramos; Pinheiro, Suzana Kanawati; Ramasawmy, Rajendranath; Silveira, Fernando Tobias; de Assis Souza, Marina; Goto, Hiro

    2017-02-01

    American tegumentary leishmaniasis (ATL) (also known as cutaneous leishmaniasis [CL]) is caused by various species of protozoa of the genus Leishmania The diagnosis is achieved on a clinical, epidemiological, and pathological basis, supported by positive parasitological exams and demonstration of leishmanin delayed-type hypersensitivity. Serological assays are not routinely used in the diagnosis because many are considered to have low sensitivity and the particular Leishmania species causing the disease can lead to variable performance. In the present study, we generated recombinant versions of two highly conserved Leishmania proteins, Leishmania (Viannia) braziliensis-derived Lb8E and Lb6H, and evaluated both in enzyme-linked immunosorbent assays (ELISA). Recombinant Lb6H (rLb6H) had better performance and reacted with 100.0% of the ATL and 89.4% of the VL samples. These reactions with rLb6H were highly specific (98.5%) when compared against those for samples from healthy control individuals. We then assessed rLb6H against sera from ATL patients infected with different species of Leishmania prevalent in Brazil [Leishmania (Leishmania) amazonensis, L (Viannia) braziliensis, and L (V) guyanensis] and samples from patients with other infectious diseases. In analyses of 500 sera, ELISA using rLb6H detected all 219 ATL samples (sensitivity of 100.0%) with an overall specificity of 93.9% (considering healthy individuals and other infectious diseases patients). Only a minority of samples from Chagas disease patients possessed antibodies against rLb6H, and all of these responses were low (with a highest reactivity index of 2.2). Taken together, our data support further evaluation of rLb6H and the potential for its routine use in the serological diagnosis of ATL. Copyright © 2017 Sato et al.

  2. Understanding serine proteases implications on Leishmania spp lifecycle.

    Science.gov (United States)

    Alves, Carlos Roberto; Souza, Raquel Santos de; Charret, Karen Dos Santos; Côrtes, Luzia Monteiro de Castro; Sá-Silva, Matheus Pereira de; Barral-Veloso, Laura; Oliveira, Luiz Filipe Gonçalves; da Silva, Franklin Souza

    2018-01-01

    Serine proteases have significant functions over a broad range of relevant biological processes to the Leishmania spp lifecycle. Data gathered here present an update on the Leishmania spp serine proteases and the status of these enzymes as part of the parasite degradome. The serine protease genes (n = 26 to 28) in Leishmania spp, which encode proteins with a wide range of molecular masses (35 kDa-115 kDa), are described along with their degrees of chromosomal and allelic synteny. Amid 17 putative Leishmania spp serine proteases, only ∼18% were experimentally demonstrated, as: signal peptidases that remove the signal peptide from secretory pre-proteins, maturases of other proteins and with metacaspase-like activity. These enzymes include those of clans SB, SC and SF. Classical inhibitors of serine proteases are used as tools for the characterization and investigation of Leishmania spp. Endogenous serine protease inhibitors, which are ecotin-like, can act modulating host actions. However, crude or synthetic based-natural serine protease inhibitors, such as potato tuber extract, Stichodactyla helianthus protease inhibitor I, fukugetin and epoxy-α-lapachone act on parasitic serine proteases and are promising leishmanicidal agents. The functional interrelationship between serine proteases and other Leishmania spp proteins demonstrate essential functions of these enzymes in parasite physiology and therefore their value as targets for leishmaniasis treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Efeito leishmanicida in vitro do látex de Croton lechleri (Euphorbiaceae

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    Ana Paula Azevedo Santos

    2016-07-01

    Full Text Available A Leishmaniose Tegumentar Americana é uma infecção causada por uma variedade de espécies de Leishmania, é transmitida ao homem por flebotomíneos. Os antimoniais pentavalentes são utilizados na quimioterapia dessa doença; no entanto, esses fármacos provocam uma série de efeitos colaterais, além de apresentar altos índices de toxicidade. Na busca por novos agentes leishmanicidas, avaliamos in vitro o extrato do látex de Croton lechleri (Sangue de dragão frente a formas promastigotas de Leishmania amazonensis e Leishmania guyanensis. O extrato foi obtido através da desidratação do látex de C. lechleri e diluído em solução 10% de etanol em salina tamponada com fosfato. As promastigotas de Leishmania foram cultivadas juntamente com o extrato nas concentrações de 6,25; 12,5 e 25μg/ mL por 72 horas. O extrato apresentou eficácia em todas as concentrações testadas apresentando um IC 50 (concentração inibitória de 5,04μg/mL para L. amazonensis e IC 50 de 9,05μg/mL para L. guyanensis. Foi realizada a avaliação citotóxica em células J774 nas mesmas concentrações usadas no ensaio leishmanicida, porém a concentração de 25μg/mL apresentou  índice de toxicidade de aproximadamente 50% para a célula hospedeira. Os testes realizados mostraram-sepromissores, pois o extrato testado também foi capaz de inibir o crescimento de promastigotas de L. amazonensis após ensaio de infecção com células J774.Palavras-chave: Croton lechleri. Atividade leishmanicida. Atividade citotóxica. ABSTRACTIn vitro leishmanicidal effect of Croton lechleri latexCutaneous Leishmaniasis is an infection caused by a several species of Leishmania, is transmitted to humans by phlebotomine sandflies. Pentavalent antimonial compounds are used in the chemotherapy of this disease; however, these drugs cause several collateral effects, besides presenting high levels of toxicity. The search for new antiLeishmanial agents, we assessed in vitro the

  4. A calmodulin-like protein (LCALA) is a new Leishmania amazonensis candidate for telomere end-binding protein.

    Science.gov (United States)

    Morea, Edna G O; Viviescas, Maria Alejandra; Fernandes, Carlos A H; Matioli, Fabio F; Lira, Cristina B B; Fernandez, Maribel F; Moraes, Barbara S; da Silva, Marcelo S; Storti, Camila B; Fontes, Marcos R M; Cano, Maria Isabel N

    2017-11-01

    Leishmania spp. telomeres are composed of 5'-TTAGGG-3' repeats associated with proteins. We have previously identified LaRbp38 and LaRPA-1 as proteins that bind the G-rich telomeric strand. At that time, we had also partially characterized a protein: DNA complex, named LaGT1, but we could not identify its protein component. Using protein-DNA interaction and competition assays, we confirmed that LaGT1 is highly specific to the G-rich telomeric single-stranded DNA. Three protein bands, with LaGT1 activity, were isolated from affinity-purified protein extracts in-gel digested, and sequenced de novo using mass spectrometry analysis. In silico analysis of the digested peptide identified them as a putative calmodulin with sequences identical to the T. cruzi calmodulin. In the Leishmania genome, the calmodulin ortholog is present in three identical copies. We cloned and sequenced one of the gene copies, named it LCalA, and obtained the recombinant protein. Multiple sequence alignment and molecular modeling showed that LCalA shares homology to most eukaryotes calmodulin. In addition, we demonstrated that LCalA is nuclear, partially co-localizes with telomeres and binds in vivo the G-rich telomeric strand. Recombinant LCalA can bind specifically and with relative affinity to the G-rich telomeric single-strand and to a 3'G-overhang, and DNA binding is calcium dependent. We have described a novel candidate component of Leishmania telomeres, LCalA, a nuclear calmodulin that binds the G-rich telomeric strand with high specificity and relative affinity, in a calcium-dependent manner. LCalA is the first reported calmodulin that binds in vivo telomeric DNA. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Componentes antiinflamatórios na saliva do Lutzomyia longipalpis, vetor da Leishmania chagasi

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    Marta Chagas Monteiro

    2005-06-01

    Full Text Available A inoculação da saliva de vetores na pele do hospedeiro é importante tanto para a alimentação do inseto quanto para a transmissão e estabelecimento de várias infecções. Em leishmaniose, vários estudos demonstram que a saliva dos vetores Lutzomyia e Phlebotomus contém substâncias com atividades imunossupressoras, imunomodulatórias, vasodilatadoras, anti-plaquetárias e anticoagulantes. Os componentes salivares auxiliam a alimentação do inseto através do aumento do fluxo sanguíneo, assim como induzem a imunossupressão no hospedeiro, o que é fundamental para o estabelecimento da infecção por Leishmania. Neste trabalho foi observado que a saliva induz a produção de IL-10, citocina antiinflamatória, não alterando a produção de IFN-g , citocina próinflamatória, no foco da inflamação. Além disso, a saliva potencializa o edema induzido por carragenina.

  6. Detection and Differentiation of Leishmania spp. in Clinical Specimens by Use of a SYBR Green-Based Real-Time PCR Assay.

    Science.gov (United States)

    de Almeida, Marcos E; Koru, Ozgur; Steurer, Francis; Herwaldt, Barbara L; da Silva, Alexandre J

    2017-01-01

    Leishmaniasis in humans is caused by Leishmania spp. in the subgenera Leishmania and Viannia Species identification often has clinical relevance. Until recently, our laboratory relied on conventional PCR amplification of the internal transcribed spacer 2 (ITS2) region (ITS2-PCR) followed by sequencing analysis of the PCR product to differentiate Leishmania spp. Here we describe a novel real-time quantitative PCR (qPCR) approach based on the SYBR green technology (LSG-qPCR), which uses genus-specific primers that target the ITS1 region and amplify DNA from at least 10 Leishmania spp., followed by analysis of the melting temperature (T m ) of the amplicons on qPCR platforms (the Mx3000P qPCR system [Stratagene-Agilent] and the 7500 real-time PCR system [ABI Life Technologies]). We initially evaluated the assay by testing reference Leishmania isolates and comparing the results with those from the conventional ITS2-PCR approach. Then we compared the results from the real-time and conventional molecular approaches for clinical specimens from 1,051 patients submitted to the reference laboratory of the Centers for Disease Control and Prevention for Leishmania diagnostic testing. Specimens from 477 patients tested positive for Leishmania spp. with the LSG-qPCR assay, specimens from 465 of these 477 patients also tested positive with the conventional ITS2-PCR approach, and specimens from 10 of these 465 patients had positive results because of retesting prompted by LSG-qPCR positivity. On the basis of the T m values of the LSG-qPCR amplicons from reference and clinical specimens, we were able to differentiate four groups of Leishmania parasites: the Viannia subgenus in aggregate; the Leishmania (Leishmania) donovani complex in aggregate; the species L (L) tropica; and the species L (L) mexicana, L (L) amazonensis, L (L) major, and L (L) aethiopica in aggregate. Copyright © 2016 American Society for Microbiology.

  7. Serological survey of Leishmania infection in dogs from the municipality of Peso da Régua (Alto Douro, Portugal) using the direct agglutination test (DAT) and fast agglutination screening test (FAST)

    NARCIS (Netherlands)

    Cardoso, Luís; Schallig, Henk D. F. H.; Neto, Francisco; Kroon, Nel; Rodrigues, Manuela

    2004-01-01

    Leishmaniasis caused by Leishmania infantum is a prevalent disease in dogs and humans. A serological survey of Leishmania infection in dogs was carried out in the endemic region of Alto Douro (north Portugal). Two hundred and ninety-four dogs from the municipality of Peso da Régua were examined for

  8. Development and evaluation of zinc phthalocyanine nanoemulsions for use in photodynamic therapy for Leishmania spp.

    Science.gov (United States)

    Betzler de Oliveira de Siqueira, Luciana; da Silva Cardoso, Verônica; Almeida Rodrigues, Igor; Lúcia Vazquez-Villa, Ana; Pereira dos Santos, Elisabete; da Costa Leal Ribeiro Guimarães, Bruno; dos Santos Cerqueira Coutinho, Cristal; Vermelho, Alane Beatriz; Ricci Junior, Eduardo

    2017-02-01

    Photodynamic therapy (PDT) combines light with photosensitizers (PS) for production of reactive oxygen species (ROS) that can kill infectious microorganisms such as bacteria, fungi and protozoa. The application of nanotechnology has enabled the advancement of PDT because many PS are insoluble in water, necessitating a nanocarrier as a physiologically acceptable carrier. Nanoemulsions are efficient nanocarriers for solubilizing liposoluble drugs, like the PS, in water. Cutaneous (CL) and mucocutaneous leishmaniasis (ML) are caused by different species of the genus Leishmania, transmitted to humans by sandfly bites. Parasites are hosted in skin macrophages producing ulcerative lesions. Thus, a topical treatment, effective and inexpensive, for CL and ML is preferable to systemic interventions. There are topical treatments like paromomycin and amphotericin B, but they have many local side effects or a very high cost, limiting their use. This work aimed to develop a zinc phthalocyanine (photosensitizer) oil-in-water nanoemulsion, essential clove oil and polymeric surfactant (Pluronic® F127) for the formulation of a topical delivery system for use in PDT against Leishmania amazonensis and Leishmania infantum. The nanoemulsion was produced by a high-energy method and characterized by size, polydispersity, morphology, pH, content and stability studies. The toxicity in the dark and the photobiological activity of the formulations were evaluated in vitro for Leishmania and macrophages. The formulation presented was pH compatible with topical use, approximately 30 nm in size, with a polydispersity index ≤0.1 and remained stable at room and refrigerator temperature during the stability study (60 days). The zinc phthalocyanine nanoemulsion is effective in PDT against Leishmania spp.; use against skin infections can be a future application of this topical formulation, avoiding the use of oral or injectable medications, decreasing systemic adverse effects.

  9. Identification of six New World Leishmania species through the implementation of a High-Resolution Melting (HRM) genotyping assay.

    Science.gov (United States)

    Hernández, Carolina; Alvarez, Catalina; González, Camila; Ayala, Martha Stella; León, Cielo Maritza; Ramírez, Juan David

    2014-11-14

    Leishmaniases are tropical zoonotic diseases, caused by parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. This eco-epidemiological complexity imposes a challenge to the detection of circulating parasite species, not only related to human cases but also infecting vectors and reservoirs. Currently, no harmonized methods have been deployed to discriminate the NW Leishmania species. Herein, we conducted a systematic and mechanistic High-Resolution Melting (HRM) assay targeted to HSP70 and ITS1. Specific primers were designed that coupled with a HRM analyses permitted to discriminate six NW Leishmania species. In order to validate the herein described algorithm, we included 35 natural isolates obtained from human cases, insect vectors and mammals. Our genotyping assay allowed the correct assignment of the six NW Leishmania species (L. mexicana, L. infantum (chagasi), L. amazonensis, L. panamensis, L. guyanensis and L. braziliensis) based on reference strains. When the algorithm was applied to a set of well-characterized strains by means of PCR-RFLP, MLEE and monoclonal antibodies (MA) we observed a tailored concordance between the HRM and PCR-RFLP/MLEE/MA (KI = 1.0). Additionally, we tested the limit of detection for the HRM method showing that this is able to detect at least 10 equivalent-parasites per mL. This is a rapid and reliable method to conduct molecular epidemiology and host-parasite association studies in endemic areas.

  10. Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 2. Resposta humoral tissular

    Directory of Open Access Journals (Sweden)

    Albino Verçosa de Magalhães

    1986-10-01

    Full Text Available Os A.A. analisaram a resposta humoral nas lesões de 90 pacientes de Leishmaniose Tegumentar — causada por Leishmania braziliensis brasiliensis —, utilizando o método da imunoperoxidase para identificar nos tecidos a presença de IgA, IgG, IgM, fração C3 do complemento e fibrina. Constataram a presença de IgA, IgC e IgM nos plasmócitos tissulares, com predomínio de IgG. Admitiram aue a passagem dessas imunoglobulinas para os tecidos possibilitando a opsonização do parasites e/ou de seus antígenos, permitiria a ocorrência de fenômenos necróticos que representam um dos mecanismos eficazes de redução da carga parasitária. Efetivamente, nas áreas de necrose e nas paredes dos vasos inflamados identificaram depósito de imunoglobulinas, fração C3 do complemento e fibrina — elementos do hospedeiro que fazem parte dos imunocomplexos. Interpretaram essa necrose tissular como o resultado da ação de imunocomplexos na região de equivalência ou com discreto excesso de antígenos ítipos ABTHTJS. A presença de antígenos parasitários, expressos nas membranas dos macrófagos quando em contato com imunoglobulinas tissulares, na fase inicial da lesão, possibilitaria a instalação de uma reação antígeno-anticorpo, a qual explicaria o aparecimento da necrose na Leishmaniose Tegumentar.

  11. Leishmania mexicana: aspectos taxonómicos y rareza de la infección humana en Três Braços, Bahia, Brasil

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    César Augusto Cuba Cuba

    1984-09-01

    Full Text Available Del estúdio de 51 stocks de Leishmania aislados de pacientes humanos de leishmaniasis cutaneomucosa en Três Braços, Bahia, Brasil, los autores describen, en detalle, el análisis de los dos únicos stocks de L. mexicana, identificando uno de ellos como L. mexicana amazonensis. El otro aislado permanece en posición taxonómica no definida pues considerándosele como un miembro de L. mexicana, encuéntranse dificultades para su identificación subespecífica. Evaluan también los parâmetros biológicos e isoenzimáticos y discuten el papel de los anticuerpos monoclonales en la tipificación de éstos stocks. Los autores remarcan la rareza de la transmisión de parásitos del complejo L. mexicana en esta región, aun cuando estudien epidemiológicamente por mais de 8 anos la infección humana.In a study of 51 stocks of Leishmania isolated from patients with cutaneous leishmaniasis in Três Braços, Bahia, Brazil 49 were characterized as L. braziliensis braziliensis. Only two L. mexicana stocks were identified. One was subspeciated as L. mexicana amazonensis. The other differed from this species and to date remains unspeciated. The biological parameters, isoenzyme analysis and monoclonal antibody findings relating to these two strains are discussed. Transmission of parasites of the mexicana complex to man have been rare in this region during the 8 years of study of the human infection.

  12. Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis Efeito combinado do óleo de essência de Chenopodium ambrosioides e drogas anti-leishmaniose nos promastigotas de Leishmania amazonensis

    OpenAIRE

    Lianet Monzote; Ana Margarita Montalvo; Ramón Scull; Migdalia Miranda; Juan Abreu

    2007-01-01

    To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against pr...

  13. Leishmania infection and blood food sources of phlebotomines in an area of Brazil endemic for visceral and tegumentary leishmaniasis

    Science.gov (United States)

    Guimarães-e-Silva, Antônia Suely; Silva, Soraia de Oliveira; Ribeiro da Silva, Rosa Cristina; Pinheiro, Valéria Cristina Soares; Rebêlo, José Manuel Macário; Melo, Maria Norma

    2017-01-01

    The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were submitted to fragment length polymorphism analysis to identify infecting species of Leishmania, and blood sources were identified for 778 of these specimens. Infection by Leishmania infantum was detected in Lutzomyia longipalpis, Lu. whitmani and Lu. termitophila; L. infantum/L. braziliensis in Lu. longipalpis, Lu. whitmani and Lu. trinidadensis; L. shawi in Lu. longipalpis; L. mexicana in Lu. longipalpis; L. braziliensis in Lu. longipalpis and Lu. whitmani; L. guyanensis in Lu. longipalpis and Lu. termitophila; L. amazonensis in Lu. longipalpis and L. lainsoni or L. naiffi in Lu. longipalpis, while Lu. longipalpis and Lu. trinidadensis were infected with unidentified Leishmania sp. Blood sources were identified in 573 individual phlebotomines and the preferred hosts were, in decreasing order, chicken, dog, rodent and human with lower preferences for pig, horse, opossum and cattle. Lu. longipalpis and Lu. whitmani performed mixed feeding on man, dog and rodent, while Lu. longipalpis was the most opportunistic species, feeding on the blood of all hosts surveyed, but preferably on dog/chicken, dog/rodent and rodent/chicken. Our findings reveal the concomitant circulation of Leishmania species that cause visceral leishmaniasis and tegumentary leishmaniasis in the study area, and explain the occurrence of autochthonous human cases of both clinical forms of leishmaniasis in Caxias, Maranhão. The results support our hypothesis that, in the municipality of Caxias, transmission

  14. Perfil de isotipos de imunoglobulinas e subclasses de IgG na leishmaniose tegumentar americana Immunoglobulin isotype and IgG subclass profiles in american tegumentary leishmaniasis

    Directory of Open Access Journals (Sweden)

    Maria Aparecida de Souza

    2005-04-01

    Full Text Available O presente trabalho avaliou o perfil de anticorpos em amostras de soro de 37 pacientes com diagnóstico clínico confirmado ou compatível com leishmaniose tegumentar americana atendidos no Hospital de Clínicas da Universidade Federal de Uberlândia, MG. Os perfis das classes de imunoglobulinas e subclasses de IgG foram analisados pelo teste ELISA indireto, utilizando-se antígeno solúvel de Leishmania (Leishmania amazonensis. A avidez dos anticorpos foi determinada pelo tratamento com uréia a 6 M, após incubação dos soros com o antígeno. Observou-se que 97%, 94,6%, 57,5 e 21,5% das amostras testadas apresentaram anticorpos anti-Leishmania das classes IgE, IgG, IgA e IgM, respectivamente e, os perfis das subclasses de IgG demonstraram, IgG1>IgG3>IgG2>IgG4. Os anticorpos IgE anti-Leishmania de alta avidez corresponderam a 44,4%. Por outro lado, IgG e IgA anti-Leishmania foram em sua maioria (62,8 e 47,8%, respectivamente, de média avidez. A variação do perfil de isotipos, bem como a avidez das imunoglobulinas refletiu a complexidade da resposta imune humoral contra a leishmaniose tegumentar americana.The present work investigated the serum antibody profiles in 37 patients with American tegumentary leishmaniasis, who were attended at Hospital de Clinicas - Universidade Federal de Uberlandia, MG, Brazil. The immunoglobulin class and IgG subclass profiles were analyzed by indirect ELISA using Leishmania (Leishmania amazonensis soluble antigen. The antibody avidity was determined by 6 M urea treatment after incubation with immunoenzymatic conjugate. It was observed that 97% of the serum samples presented anti-Leishmania antibodies for IgE class, 94.6% IgG, 57.5% IgA and 21.5% IgM class. For IgG subclasses the profiles were in the following order of frequency: IgG1>IgG3>IgG2>IgG4. High avidity of anti-Leishmania IgE antibodies was found in 44.4% of the samples. On the other hand, moderate avidity of specific IgG and IgA was observed in 62

  15. Molecular characterization and functional analysis of pteridine reductase in wild-type and antimony-resistant Leishmania lines.

    Science.gov (United States)

    de Souza Moreira, Douglas; Ferreira, Rafael Fernandes; Murta, Silvane M F

    2016-01-01

    Pteridine reductase (PTR1) is an NADPH-dependent reductase that participates in the salvage of pteridines, which are essential to maintain growth of Leishmania. In this study, we performed the molecular characterization of ptr1 gene in wild-type (WTS) and SbIII-resistant (SbR) lines from Leishmania guyanensis (Lg), Leishmania amazonensis (La), Leishmania braziliensis (Lb) and Leishmania infantum (Li), evaluating the chromosomal location, mRNA levels of the ptr1 gene and PTR1 protein expression. PFGE results showed that the ptr1 gene is located in a 797 kb chromosomal band in all Leishmania lines analyzed. Interestingly, an additional chromosomal band of 1070 kb was observed only in LbSbR line. Northern blot results showed that the levels of ptr1 mRNA are increased in the LgSbR, LaSbR and LbSbR lines. Western blot assays using the polyclonal anti-LmPTR1 antibody demonstrated that PTR1 protein is more expressed in the LgSbR, LaSbR and LbSbR lines compared to their respective WTS counterparts. Nevertheless, no difference in the level of mRNA and protein was observed between the LiWTS and LiSbR lines. Functional analysis of PTR1 enzyme was performed to determine whether the overexpression of ptr1 gene in the WTS L. braziliensis and L. infantum lines would change the SbIII-resistance phenotype of transfected parasites. Western blot results showed that the expression level of PTR1 protein was increased in the transfected parasites compared to the non-transfected ones. IC50 analysis revealed that the overexpression of ptr1 gene in the WTS L. braziliensis line increased 2-fold the SbIII-resistance phenotype compared to the non-transfected counterpart. Furthermore, the overexpression of ptr1 gene in the WTS L. infantum line did not change the SbIII-resistance phenotype. These results suggest that the PTR1 enzyme may be implicated in the SbIII-resistance phenotype in L. braziliensis line. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Anti-HIV drugs, lopinavir/ritonavir and atazanavir, modulate innate immune response triggered by Leishmania in macrophages: the role of NF-κB and PPAR-γ.

    Science.gov (United States)

    Alves, Érica Alessandra Rocha; de Miranda, Marthina Gomes; Borges, Tatiana Karla; Magalhães, Kelly Grace; Muniz-Junqueira, Maria Imaculada

    2015-02-01

    This study evaluated the influence of HIV protease inhibitors lopinavir/ritonavir (LPV/RTV) and atazanavir (ATV) on macrophage functions during their first interaction with Leishmania. Macrophages from BALB/c mice treated for 10days with LPV/RTV and ATV, infected or not in vitro with L. (L.) amazonensis, were used to investigate the effects of these drugs on infection index, leishmanicidal capacity, cytokine production and PPAR-γ and RelB expression. LPV/RTV and ATV treatments significantly increased the infection index and the percentage of Leishmania-infected macrophages compared to untreated infected macrophages. There was no correlated increase in the production of NO and H2O2 leishmanicidal molecules. Promastigotes derived from Leishmania-infected macrophages from LPV/RTV and ATV-treated BALB/c mice had an in vitro growth 45.1% and 56.4% higher in groups treated with LPV/RTV and ATV than with PBS in culture. ATV treatment reduced IL-12p70 and IL-10 secretion in Leishmania-infected macrophages, but had no effect on IL-23 and TNF production. LPV reduced IL-10 and had no effect on IL-12p70, TNF and IL-23 secretion. ATV treatment decreased PPAR-γ expression in Leishmania-infected macrophages compared to untreated infected macrophages. In addition, LPV/RTV, but not ATV, reduced RelB cytoplasm-to-nucleus translocation in Leishmania-infected macrophages. Results showed that LPV/RTV and ATV HIV protease inhibitors were able to modulate innate defense mechanisms against Leishmania via different intracellular pathways. Although HIV protease inhibitors are highly efficient to control the Human Immunodeficiency Virus, these drugs might also influence the course of leishmaniasis in HIV-Leishmania-co-infected individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. In vitro evaluation of the anti-leishmanial activity and toxicity of PK11195

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    Carlos Eduardo Sampaio Guedes

    2018-02-01

    Full Text Available BACKGROUND Leishmaniasis, one of the most neglected diseases, is a serious public health problem in many countries, including Brazil. Currently available treatments require long-term use and have serious side effects, necessitating the development of new therapeutic interventions. Because translocator protein (TSPO levels are reduced in Leishmania amazonensis-infected cells and because this protein participates in apoptosis and immunomodulation, TSPO represents a potential target for Leishmania chemotherapy. The present study evaluated PK11195, a ligand of this protein, as an anti-leishmanial agent. OBJECTIVE To evaluate the leishmanicidal activity of PK11195 against L. amazonensis in infected CBA mouse macrophages in vitro. METHODS The viability of axenic L. amazonensis, Leishmania major, and Leishmania braziliensis promastigotes was assessed after 48 h treatment with PK11195 (0.2-400 µM. Additionally, intracellular parasite viability was evaluated to determine IC50 values and the number of viable parasites in infected macrophages treated with PK11195 (50-100 µM. Infected macrophages were then treated with PK11195 (25-100 µM to determine the percentage of L. amazonensis-infected cells and the number of parasites per infected cell. Electron microscopy was used to investigate morphological changes caused by PK11195. The production of free oxygen radicals, nitric oxide, and pro-inflammatory cytokines was also evaluated in infected macrophages treated with PK11195 and primed or not primed with IFN-γ. FINDINGS Median IC50 values for PK11195 were 14.2 µM for L. amazonensis, 8.2 µM for L. major, and 3.5 µM for L. braziliensis. The selective index value for L. amazonensis was 13.7, indicating the safety of PK11195 for future testing in mammals. Time- and dose-dependent reductions in the percentage of infected macrophages, the number of parasites per infected macrophage, and the number of viable intracellular parasites were observed. Electron

  18. Combined effect of the essential oil from Chenopodium ambrosioides and antileishmanial drugs on promastigotes of Leishmania amazonensis

    OpenAIRE

    Monzote,Lianet; Montalvo,Ana Margarita; Scull,Ramón; Miranda,Migdalia; Abreu,Juan

    2007-01-01

    To date, there are no vaccines against Leishmania, and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice used for leishmaniasis therapy are significantly toxic, expensive and with a growing frequency of refractory infections. Because of these limitations, a combination therapy is the better hope. This work demonstrates that the essential oil from Chenopodium ambrosioides shows a synergic activity after incubation in conjunction with pentamidine against pr...

  19. Estudo histológico e parasitológico do trato gastrintestinal de cães infectados com Leishmania (Leishmania) chagasi

    OpenAIRE

    Aldair Junio Woyames Pinto

    2011-01-01

    São poucas as descrições das alterações patológicas e parasitológicas relacionadas ao envolvimento do trato gastrointestinal (TGI) na leishmaniose visceral canina e, sobretudo considerando-se o TGI de forma sistemática. Assim, neste trabalho objetivou-se um estudo sistemático, clínico, anatomopatológico e parasitológico do TGI de cães naturalmente infectados com Leishmania (Leishmania) chagasi provenientes da região metropolitana de Belo Horizonte, MG. Após confirmação sorológica (RIFI e ELIS...

  20. Characterization of a Novel Endoplasmic Reticulum Protein Involved in Tubercidin Resistance in Leishmania major.

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    Juliana Ide Aoki

    2016-09-01

    Full Text Available Tubercidin (TUB is a toxic adenosine analog with potential antiparasitic activity against Leishmania, with mechanism of action and resistance that are not completely understood. For understanding the mechanisms of action and identifying the potential metabolic pathways affected by this drug, we employed in this study an overexpression/selection approach using TUB for the identification of potential targets, as well as, drug resistance genes in L. major. Although, TUB is toxic to the mammalian host, these findings can provide evidences for a rational drug design based on purine pathway against leishmaniasis.After transfection of a cosmid genomic library into L. major Friedlin (LmjF parasites and application of the overexpression/selection method, we identified two cosmids (cosTUB1 and cosTU2 containing two different loci capable of conferring significant levels of TUB resistance. In the cosTUB1 contained a gene encoding NUPM1-like protein, which has been previously described as associated with TUB resistance in L. amazonensis. In the cosTUB2 we identified and characterized a gene encoding a 63 kDa protein that we denoted as tubercidin-resistance protein (TRP. Functional analysis revealed that the transfectants were less susceptible to TUB than LmjF parasites or those transfected with the control vector. In addition, the trp mRNA and protein levels in cosTUB2 transfectants were higher than LmjF. TRP immunolocalization revealed that it was co-localized to the endoplasmic reticulum (ER, a cellular compartment with many functions. In silico predictions indicated that TRP contains only a hypothetical transmembrane domain. Thus, it is likely that TRP is a lumen protein involved in multidrug efflux transport that may be involved in the purine metabolic pathway.This study demonstrated for the first time that TRP is associated with TUB resistance in Leishmania. The next challenge is to determine how TRP mediates TUB resistance and whether purine

  1. Characterization of a Novel Endoplasmic Reticulum Protein Involved in Tubercidin Resistance in Leishmania major.

    Science.gov (United States)

    Aoki, Juliana Ide; Coelho, Adriano Cappellazzo; Muxel, Sandra Marcia; Zampieri, Ricardo Andrade; Sanchez, Eduardo Milton Ramos; Nerland, Audun Helge; Floeter-Winter, Lucile Maria; Cotrim, Paulo Cesar

    2016-09-01

    Tubercidin (TUB) is a toxic adenosine analog with potential antiparasitic activity against Leishmania, with mechanism of action and resistance that are not completely understood. For understanding the mechanisms of action and identifying the potential metabolic pathways affected by this drug, we employed in this study an overexpression/selection approach using TUB for the identification of potential targets, as well as, drug resistance genes in L. major. Although, TUB is toxic to the mammalian host, these findings can provide evidences for a rational drug design based on purine pathway against leishmaniasis. After transfection of a cosmid genomic library into L. major Friedlin (LmjF) parasites and application of the overexpression/selection method, we identified two cosmids (cosTUB1 and cosTU2) containing two different loci capable of conferring significant levels of TUB resistance. In the cosTUB1 contained a gene encoding NUPM1-like protein, which has been previously described as associated with TUB resistance in L. amazonensis. In the cosTUB2 we identified and characterized a gene encoding a 63 kDa protein that we denoted as tubercidin-resistance protein (TRP). Functional analysis revealed that the transfectants were less susceptible to TUB than LmjF parasites or those transfected with the control vector. In addition, the trp mRNA and protein levels in cosTUB2 transfectants were higher than LmjF. TRP immunolocalization revealed that it was co-localized to the endoplasmic reticulum (ER), a cellular compartment with many functions. In silico predictions indicated that TRP contains only a hypothetical transmembrane domain. Thus, it is likely that TRP is a lumen protein involved in multidrug efflux transport that may be involved in the purine metabolic pathway. This study demonstrated for the first time that TRP is associated with TUB resistance in Leishmania. The next challenge is to determine how TRP mediates TUB resistance and whether purine metabolism is affected

  2. Estudo, ao microscópio óptico e eletrônico, do rim de caes natural e experimentalmente infectados com Leishmania (Leishmania chagasi

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    Washington Luiz Tafuri

    1989-06-01

    Full Text Available Os autores estudam os rins de 4 cães infectados com Leishmania (Leishmania chagasi. Dois animais (um macho e uma fêmea naturalmente infectados foram sacrificados 18 meses após sua permanência no laboratório. Dois machos foram inoculados por via endovenosa, com lxlO6 promastigotas da cepa MHO/BR/70/BH46 e sacrificados após 18 meses e 2 anos, respectivamente. Em todos os animais os rins estavam lesados. As alterações encontradas foram: (1 glomerulonefrite mesangioproliferativa focal ou difusa, com pronunciada hipertrofia e hiperplasia das células mesangiais e com alargamento da matriz; (2 espessamento da membrana basal com depósitos eletrondensos; (3 nefrite intersticial intertubular crônica com exsudação plasmocitária intensa. (4 degeneração albuminosa dos túbulos renais. Baseados nos achados os autores discutem os prováveis mecanismos patogenéticos.

  3. Antitumoral, antileishmanial and antimalarial activity of pentacyclic 1,4-naphthoquinone derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alcides J.M. da; Netto, Chaquip D; Costa, Paulo R.R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Nucleo de Pesquisas de Produtos Naturais. Lab. de Quimica Bioorganica; Pacienza-Lima, Wallace; Rossi-Bergmann, Bartira; Maurel, Severine; Valentin, Alexis; Costa, Paulo R.R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho; Torres-Santos, Eduardo Caio [Instituto Oswaldo Cruz, Rio de Janeiro, RJ (Brazil). Lab. de Bioquimica de Tripanosomatideos; Maurel, Severine; Valentin, Alexis [Universite Paul Sabatier, Toulouse (France). Faculte de Pharmacie. Pharmacochimie des Substances Naturelles et Pharmacophores Redox

    2009-07-01

    Pterocarpanquinones 8a-c, previously synthesized in our laboratory, and an homologous series of derivatives, compounds 9a-c prepared in this work, were evaluated on breast cancer cells (MCF-7) and on the parasites Leishmania amazonensis and Plasmodium falciparum, in culture. Compounds 8a-c were more potent than 9a-c on tumor cells and Leishmania amazonensis. On the other hand, 9a-c showed to be more active on Plasmodium falciparum. All the compounds studied were bioselective, presenting negligible cytotoxicity against fresh murine lymphocytes and human lymphocytes activated by the mitogen phytohemagglutinin (PHA). (author)

  4. Antitumoral, antileishmanial and antimalarial activity of pentacyclic 1,4-naphthoquinone derivatives

    International Nuclear Information System (INIS)

    Silva, Alcides J.M. da; Netto, Chaquip D.; Costa, Paulo R.R.; Pacienza-Lima, Wallace; Rossi-Bergmann, Bartira; Maurel, Severine; Valentin, Alexis; Costa, Paulo R.R.; Torres-Santos, Eduardo Caio; Maurel, Severine; Valentin, Alexis

    2009-01-01

    Pterocarpanquinones 8a-c, previously synthesized in our laboratory, and an homologous series of derivatives, compounds 9a-c prepared in this work, were evaluated on breast cancer cells (MCF-7) and on the parasites Leishmania amazonensis and Plasmodium falciparum, in culture. Compounds 8a-c were more potent than 9a-c on tumor cells and Leishmania amazonensis. On the other hand, 9a-c showed to be more active on Plasmodium falciparum. All the compounds studied were bioselective, presenting negligible cytotoxicity against fresh murine lymphocytes and human lymphocytes activated by the mitogen phytohemagglutinin (PHA). (author)

  5. Characterization of a midgut mucin-like glycoconjugate of Lutzomyia longipalpis with a potential role in Leishmania attachment.

    Science.gov (United States)

    Myšková, Jitka; Dostálová, Anna; Pěničková, Lucie; Halada, Petr; Bates, Paul A; Volf, Petr

    2016-07-25

    Leishmania parasites are transmitted by phlebotomine sand flies and a crucial step in their life-cycle is the binding to the sand fly midgut. Laboratory studies on sand fly competence to Leishmania parasites suggest that the sand flies fall into two groups: several species are termed "specific/restricted" vectors that support the development of one Leishmania species only, while the others belong to so-called "permissive" vectors susceptible to a wide range of Leishmania species. In a previous study we revealed a correlation between specificity vs permissivity of the vector and glycosylation of its midgut proteins. Lutzomyia longipalpis and other four permissive species tested possessed O-linked glycoproteins whereas none were detected in three specific vectors examined. We used a combination of biochemical, molecular and parasitological approaches to characterize biochemical and biological properties of O-linked glycoprotein of Lu. longipalpis. Lectin blotting and mass spectrometry revealed that this molecule with an apparent molecular weight about 45-50 kDa corresponds to a putative 19 kDa protein with unknown function detected in a midgut cDNA library of Lu. longipalpis. We produced a recombinant glycoprotein rLuloG with molecular weight around 45 kDa. Anti-rLuloG antibodies localize the native glycoprotein on epithelial midgut surface of Lu. longipalpis. Although we could not prove involvement of LuloG in Leishmania attachment by blocking the native protein with anti-rLuloG during sand fly infections, we demonstrated strong binding of rLuloG to whole surface of Leishmania promastigotes. We characterized a novel O-glycoprotein from sand fly Lutzomyia longipalpis. It has mucin-like properties and is localized on the luminal side of the midgut epithelium. Recombinant form of the protein binds to Leishmania parasites in vitro. We propose a role of this molecule in Leishmania attachment to sand fly midgut.

  6. Murine cutaneous leishmaniasis investigated by MALDI mass spectrometry imaging.

    Science.gov (United States)

    Negrão, Fernanda; de O Rocha, Daniele F; Jaeeger, Caroline F; Rocha, Francisca J S; Eberlin, Marcos N; Giorgio, Selma

    2017-09-26

    Imaging mass spectrometry (IMS) is recognized as a powerful tool to investigate the spatial distribution of untargeted or targeted molecules of a wide variety of samples including tissue sections. Leishmania is a protozoan parasite that causes different clinical manifestations in mammalian hosts. Leishmaniasis is a major public health risk in different continents and represents one of the most important neglected diseases. Cutaneous lesions from mice experimentally infected with Leishmania spp. were investigated by matrix-assisted laser desorption ionization MS using the SCiLS Lab software for statistical analysis. Being applied to cutaneous leishmaniasis (CL) for the first time, MALDI-IMS was used to search for peptides and low molecular weight proteins (2-10 kDa) as candidates for potential biomarkers. Footpad sections of Balb/c mice infected with (i) Leishmania amazonensis or (ii) Leishmania major were imaged. The comparison between healthy and infected skin highlighted a set of twelve possible biomarker proteins for L. amazonenis and four proteins for L. major. Further characterization of these proteins could reveal how these proteins act in pathology progression and confirm their values as biomarkers.

  7. Cura espontânea da leishmaniose causada por Leishmania Viannia Braziliensis em lesões cutâneas

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    Jackson Maurício Lopes Costa

    1990-12-01

    Full Text Available Os autores relatam que durante 14 anos de trabalho clínico em campo, realizado nas comunidades de Três Braços e Corte de Pedra, Bahia, acompanharam 1.416 pacientes portadores de Leishmaniose Tegumentar Americana, cuja espécie envolvida na transmissão, é predominantemente a Leishmania Viannia brasilienses. A terapêutica utilizada rotineiramente nos casos é o antimoniato-N-metilglucamina (Glucantime. Contudo, 16 pacientes do sexo masculino recusaram-se a utilizar a medicação e 6 do sexo feminino encontravam-se em período gestacional, portanto não utilizaram o medicamento. Estes pacientes foram acompanhados por um período entre 4 a 12 anos, a partir do diagnóstico. Observou-se que em 9 pacientes (40,9% desta casuística, o tempo de cicatrizaçâo após o aparecimento da lesão, pode ser calculado em 6 meses de evolução. Quando se eleva a observação para 12 meses, temos que 19 pacientes (86,3% cicatrizaram suas lesões neste período. Em 3 casos (13,6% as lesões permaneceram ativas por mais de 12 meses. Conclui-se que os determinantes da cicatrizaçâo natural das lesões produzidas por Leishmania Viannia Braziliensis permanecem desconhecidos, dificultando para nós entendermos e compararmos aos efeitos das drogas utilizadas no tratamento da leishmaniose tegumentar.In field clinics in the comunities of Três Braços and Corte de Pedra, Bahia, we have attended 1.416 patients with tegumentary leishmaniasis in fourteen years, the predomi nant species in transmission is Leishmania Viannia brasiliensis (LVB. Because of the danger of metastasis with this infection treatment was routinely recomended with Glucantime. However sixteen patients refused injection therapy and six women were pregnant when seen and not treated. All patients were followed up in our clinic. All these patients closed their skin ulcers although one subsequently relapsed. Patients were followed up for variable periods (four to twelve years, after the diagnosis. In

  8. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

    Science.gov (United States)

    Ricci-Azevedo, Rafael; Oliveira, Aline Ferreira; Conrado, Marina C A V; Carvalho, Fernanda Caroline; Roque-Barreira, Maria Cristina

    2016-04-01

    ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an

  9. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

    Directory of Open Access Journals (Sweden)

    Rafael Ricci-Azevedo

    2016-04-01

    Full Text Available ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1 immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS, form neutrophil extracellular traps (NETs and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF and interleukin-1beta (IL-1β release; otherwise, transforming growth factor-beta (TGF-β production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be

  10. Effect of ionizing radiation on the morphology, physiology and growth of Leishmania ssp; Acao da radiacao ionizante sobre a morfologia, fisiologia e crescimento da Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Franco C.; Spencer, Patrick J.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Junior A, Heitor F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Instituto de Medicina Tropical

    2000-07-01

    The Leishmania spp is a pathogenic protozoan, which cause different diseases in man. The human diseases, in America, caused by this group of protozoa are divided in cutaneous or tegumentar and visceral, known as kala-azar. In this work, our principal study object was the specie that causes tegumentar leishmaniasis, in Brazil. Metabolic studies of cellular respiration and proteins and nucleic acids synthesis were accomplished using radiation as a form of sterilizing the parasites without however affecting their immunogenic capacity The promastigotes forms of irradiated Leishmania spp were totally sterilized with the dose of 1500 Gy, with their reproductive and nucleic acids, as well as protein synthesis capacity blocked. (author)

  11. Discovery of novel inhibitors for Leishmania nucleoside diphosphatase kinase (NDK) based on its structural and functional characterization

    Science.gov (United States)

    Mishra, Arjun K.; Singh, Nidhi; Agnihotri, Pragati; Mishra, Shikha; Singh, Saurabh P.; Kolli, Bala K.; Chang, Kwang Poo; Sahasrabuddhe, Amogh A.; Siddiqi, M. I.; Pratap, J. Venkatesh

    2017-06-01

    Nucleoside diphosphate kinases (NDKs) are ubiquitous enzymes that catalyze the transfer of the γ-phosphate moiety from an NTP donor to an NDP acceptor, crucial for maintaining the cellular level of nucleoside triphosphates (NTPs). The inability of trypanosomatids to synthesize purines de novo and their dependence on the salvage pathway makes NDK an attractive target to develop drugs for the diseases they cause. Here we report the discovery of novel inhibitors for Leishmania NDK based on the structural and functional characterization of purified recombinant NDK from Leishmania amazonensis. Recombinant LaNDK possesses auto-phosphorylation, phosphotransferase and kinase activities with Histidine 117 playing an essential role. LaNDK crystals were grown by hanging drop vapour diffusion method in a solution containing 18% PEG-MME 500, 100 mM Bis-Tris propane pH 6.0 and 50 mM MgCl2. It belongs to the hexagonal space group P6322 with unit cell parameters a = b = 115.18, c = 62.18 Å and α = β = 90°, γ = 120°. The structure solved by molecular replacement methods was refined to crystallographic R-factor and Rfree values of 22.54 and 26.52%, respectively. Molecular docking and dynamics simulation -based virtual screening identified putative binding compounds. Protein inhibition studies of selected hits identified five inhibitors effective at micromolar concentrations. One of the compounds showed 45% inhibition of Leishmania promastigotes proliferation. Analysis of inhibitor-NDK complexes reveals the mode of their binding, facilitating design of new compounds for optimization of activities as drugs against leishmaniasis.

  12. The cytotoxic activity of miltefosine against Leishmania and macrophages is associated with dynamic changes in plasma membrane proteins.

    Science.gov (United States)

    Fernandes, Kelly Souza; de Souza, Paulo Eduardo Narcizo; Dorta, Miriam Leandro; Alonso, Antonio

    2017-01-01

    In this study, we combined electron paramagnetic resonance (EPR) spectroscopy with an analysis of biophysical cellular parameters to study the mechanisms underlying the in vitro anti-leishmanial activity of miltefosine (MT). A thiol-specific spin label attached to membrane-bound proteins of Leishmania amazonensis and peritoneal macrophages indicated that MT may bind to plasma membrane proteins in large quantities via a detergent-like action and cause structural changes associated with a marked increase in dynamics and exposure to an aqueous environment. EPR spectra of a spin-labeled stearic acid indicated strong interactions between the probe and membrane proteins and a marked increase in the membrane fluidity of MT-treated cells. The cytotoxicity of MT was found to depend on the cell concentration used in the assay. This dependence was described by an equation involving the 50% inhibitory concentrations of MT in the aqueous medium (c w50 ) and the cell membrane (c m50 ) and the membrane-aqueous medium partition coefficient of MT (K). With a c w50 of 8.7μM, macrophages were less sensitive to MT than amastigotes and promastigotes of Leishmania, which had c w50 values of 2.4-3.1μM. The estimated c m50 of MT for Leishmania was 1.8M, which appears sufficient to cause ruptures or formation of pores in the plasma membrane. Additionally, we demonstrated that the changes in the plasma membrane detected by EPR spectroscopy occurred at cytotoxic concentrations of MT, as assessed through in vitro assays. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Distribución geográfica de especies de Leishmania aisladas de pacientes consultantes al Instituto Nacional de Dermatología Federico Lleras Acosta, E.S.E., 1995-2005

    Directory of Open Access Journals (Sweden)

    Clemencia Elena Ovalle

    2006-10-01

    Full Text Available Introducción. El mapa de la distribución de especies de Leishmania en Colombia no se ha actualizado desde hace siete años. Objetivo. Describir la distribución de las especies de Leishmania a partir de los aislamientos de pacientes consultantes al Instituto Nacional de Dermatología durante el período 1995 a 2005 Materiales y métodos. Se realizó un estudio descriptivo de distribución geográfica de las especies de Leishmania, a partir de los aislamientos obtenidos de 137 pacientes consultantes al Instituto Nacional de Dermatología Federico Lleras Acosta E. S. E, con diagnóstico confirmado de leishmaniasis. Se revisó la historia clínica obteniendo la información de forma clínica, sitio probable de infección, edad y género. Se tomaron y cultivaron muestras de las lesiones y los aislamientos se tipificaron por anticuerpos monoclonales, comparando el 10% de los resultados con los obtenidos por reacción en cadena de la polimerasa (PCR y patrones isoenzimáticos. Resultados. La frecuencia encontrada de los 137 aislamientos fue: Leishmania panamensis 74,45%; Leishmania braziliensis15,33%; Leishmania guyanensis 0,73%; Complejo Leishmania mexicana 3,65%, Leishmania mexicana 5,11% y el 0,73% restante correspondió a un aislamiento que no se pudo caracterizar por anticuerpos monoclonales. La distribución de L. braziliensis, L. panamensis y L. guyanensis fue concordante con lo reportado en estudios anteriores pero para las especies del complejo L. mexicana se encontraron procedencias no reportadas previamente: Caldas, Santander, Cundinamarca, Caquetá, Casanare, Cauca y Valle del Cauca. Conclusión. El complejo L. mexicana presenta una distribución más amplia de la reportada previamente. La utilidad de los monoclonales especie-específicos, los patrones isoenzimáticos y la PCR para L. mexicana y L. amazonensis fue limitada.

  14. The yeast Scheffersomyces amazonensis is an efficient xylitol producer.

    Science.gov (United States)

    Cadete, Raquel M; Melo-Cheab, Monaliza A; Viana, Adriana L; Oliveira, Evelyn S; Fonseca, César; Rosa, Carlos A

    2016-12-01

    This study assessed the efficiency of Scheffersomyces amazonensis UFMG-CM-Y493 T , cultured in xylose-supplemented medium (YPX) and rice hull hydrolysate (RHH), to convert xylose to xylitol under moderate and severe oxygen limitation. The highest xylitol yields of 0.75 and 1.04 g g -1 in YPX and RHH, respectively, were obtained under severe oxygen limitation. However, volumetric productivity in RHH was ninefold decrease than that in YPX medium. The xylose reductase (XR) and xylitol dehydrogenase (XDH) activities in the YPX cultures were strictly dependent on NADPH and NAD + respectively, and were approximately 10% higher under severe oxygen limitation than under moderate oxygen limitation. This higher xylitol production observed under severe oxygen limitation can be attributed to the higher XR activity and shortage of the NAD + needed by XDH. These results suggest that Sc. amazonensis UFMG-CM-Y493 T is one of the greatest xylitol producers described to date and reveal its potential use in the biotechnological production of xylitol.

  15. The principal reservoir host of cutaneous leishmaniasis in the urban areas of Manaus, Central Amazon of Brazil

    Directory of Open Access Journals (Sweden)

    Jorge R. Arias

    1981-09-01

    Full Text Available Twenty one opossums (Didelphis marsupialis from disturbed primary forest in the vicinity of Manaus, and seven from an isolated island of secondary vegetation within the city of Manaus, were examined for the presence of Leishmania. Of the opossums from the primary forests, 13 (61.9% were found to be positive for Leishmania braziliensis guyanenesis. One additional opossum was found to be positive for Le. mexicana amazonensis. A simple and economical trapping technique for opossums is presented here, and a control method in special cases is suggested.Vinte e uma mucuras (Didelphis marsupialis, procedentes de uma floresta primária explorada, e sete de uma vegetação secundária em uma ilha isolada, nas cercanias de Manaus, foram examinadas para detectar a presença de Leishmania. Das mucuras da floresta primária, 13 (61.9% foram detectadas positivas para Leishmania braziliensis guyanensis. Somente uma mucura foi dada como positiva para Le.mexicana amozonensis. Apresentamos aqui uma técnica simples e economica para captura de mucuras e e sugerido um método de controle, em casos especiais.

  16. Leishmania mexicana amazonensis: heterogeneity in 5-nucleotidase and peroxidase activities of mononuclear phagocytes during in vivo and in vitro infection

    OpenAIRE

    Côrte-Real, Suzana; Grimaldi Junior, Gabriel; Meirelles, Maria de Nazareth Leal de

    1988-01-01

    The degree of maturation of cells of the Mononuclear Phagocyte System (MPS), during in vivo and in vitro infection by Leishmania mexicana amazonenesis, was evaluated in this study. The macrophages' differentiation was assayed by cytochemical characterization at the ultrastrctural level, using two well-established markers: 5'-nucleotidase enzyme activity, for revealing the mature cells, and the peroxidase activity present in the cell granules to demonstrate immature mononuclear phagocytes. onl...

  17. Purification and Biochemical Characterization of Three Myotoxins from Bothrops mattogrossensis Snake Venom with Toxicity against Leishmania and Tumor Cells

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    Andréa A. de Moura

    2014-01-01

    Full Text Available Bothrops mattogrossensis snake is widely distributed throughout eastern South America and is responsible for snakebites in this region. This paper reports the purification and biochemical characterization of three new phospholipases A2 (PLA2s, one of which is presumably an enzymatically active Asp49 and two are very likely enzymatically inactive Lys49 PLA2 homologues. The purification was obtained after two chromatographic steps on ion exchange and reverse phase column. The 2D SDS-PAGE analysis revealed that the proteins have pI values around 10, are each made of a single chain, and have molecular masses near 13 kDa, which was confirmed by MALDI-TOF mass spectrometry. The N-terminal similarity analysis of the sequences showed that the proteins are highly homologous with other Lys49 and Asp49 PLA2s from Bothrops species. The PLA2s isolated were named BmatTX-I (Lys49 PLA2-like, BmatTX-II (Lys49 PLA2-like, and BmatTX-III (Asp49 PLA2. The PLA2s induced cytokine release from mouse neutrophils and showed cytotoxicity towards JURKAT (leukemia T and SK-BR-3 (breast adenocarcinoma cell lines and promastigote forms of Leishmania amazonensis. The structural and functional elucidation of snake venoms components may contribute to a better understanding of the mechanism of action of these proteins during envenomation and their potential pharmacological and therapeutic applications.

  18. Increased transmission potential of Leishmania major/Leishmania infantum hybrids

    OpenAIRE

    Volf, Petr; Benkova, Ivana; Myskova, Jitka; Sadlova, Jovana; Campino, Lenea; Ravel, Christophe

    2007-01-01

    Development of Leishmania infantum/Leishmania major hybrids was studied in two sand fly species. In Phlebotomus papatasi, which supported development of L. major but not L. infantum, the hybrids produced heavy late-stage infections with high numbers of metacyclic promastigotes. In the permissive vector Lutzomyia longipalpis, all Leishmania strains included in this study developed well. Hybrids were found to express L. major lipophosphoglycan, apparently enabling them to survive in P. papatasi...

  19. Amastigota forms resembling Leishmania sp. on corneal ulceration in a dog: case report Formas amastigotas compatíveis com Leishmania sp. em ulceração corneal de cão: relato de caso

    Directory of Open Access Journals (Sweden)

    F.L.C. Brito

    2007-02-01

    Full Text Available One dog with visceral leishmaniasis is reported presenting cutaneous lesions, cachexia, and corneal ulceration. Parasitological and serological diagnoses were performed by exam of contents of the aspirative punction of the bone marrow and by immunofluorecence, respectively. Amastigota forms resembling Leishmania sp. were visualized by citology.Relata-se o caso de um cão com leishmaniose visceral apresentando lesões cutâneas, caquexia e úlcera de córnea. Realizou-se o diagnóstico parasitológico e sorológico por meio de exame do material da medula óssea e por imunofluorescência indireta, respectivamente. À citologia da úlcera corneana, visibilizaram-se formas amastigotas compatíveis com Leishmania sp.

  20. Antiprotozoal Activity of Quinonemethide Triterpenes from Maytenus ilicifolia (Celastraceae

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    Maysa Furlan

    2013-01-01

    Full Text Available The present study describes the leishmanicidal and trypanocidal activities of two quinonemethide triterpenes, maytenin (1 and pristimerin (2, isolated from Maytenus ilicifolia root barks (Celastraceae. The compounds were effective against the Trypanosomatidae Leishmania amazonensis and Leishmania chagasi and Trypanosoma cruzi, etiologic agents of leishmaniasis and Chagas’ disease, respectively. The quinonemethide triterpenes 1 and 2 exhibited a marked in vitro leishmanicidal activity against promastigotes and amastigotes with 50% inhibitory concentration (IC50 values of less than 0.88 nM. Both compounds showed IC50 lower than 0.3 nM against Trypanosoma cruzi epimastigotes. The selectivity indexes (SI based on BALB/c macrophages for L. amazonensis and L. chagasi were 243.65 and 46.61 for (1 and 193.63 and 23.85 for (2 indicating that both compounds presented high selectivity for Leishmania sp. The data here presented suggests that these compounds should be considered in the development of new and more potent drugs for the treatment of leishmaniasis and Chagas’ disease.

  1. Antiprotozoal activity of quinonemethide triterpenes from Maytenus ilicifolia (Celastraceae).

    Science.gov (United States)

    Dos Santos, Vania A F F M; Leite, Karoline M; da Costa Siqueira, Mariana; Regasini, Luis O; Martinez, Isabel; Nogueira, Camila T; Galuppo, Mariana Kolos; Stolf, Beatriz S; Pereira, Ana Maria Soares; Cicarelli, Regina M B; Furlan, Maysa; Graminha, Marcia A S

    2013-01-15

    The present study describes the leishmanicidal and trypanocidal activities of two quinonemethide triterpenes, maytenin (1) and pristimerin (2), isolated from Maytenus ilicifolia root barks (Celastraceae). The compounds were effective against the Trypanosomatidae Leishmania amazonensis and Leishmania chagasi and Trypanosoma cruzi, etiologic agents of leishmaniasis and Chagas' disease, respectively. The quinonemethide triterpenes 1 and 2 exhibited a marked in vitro leishmanicidal activity against promastigotes and amastigotes with 50% inhibitory concentration (IC(50)) values of less than 0.88 nM. Both compounds showed IC(50) lower than 0.3 nM against Trypanosoma cruzi epimastigotes. The selectivity indexes (SI) based on BALB/c macrophages for L. amazonensis and L. chagasi were 243.65 and 46.61 for (1) and 193.63 and 23.85 for (2) indicating that both compounds presented high selectivity for Leishmania sp. The data here presented suggests that these compounds should be considered in the development of new and more potent drugs for the treatment of leishmaniasis and Chagas' disease.

  2. Prevalence and Distribution of Leishmania RNA Virus 1 in Leishmania Parasites from French Guiana.

    Science.gov (United States)

    Ginouvès, Marine; Simon, Stéphane; Bourreau, Eliane; Lacoste, Vincent; Ronet, Catherine; Couppié, Pierre; Nacher, Mathieu; Demar, Magalie; Prévot, Ghislaine

    2016-01-01

    In South America, the presence of the Leishmania RNA virus type 1 (LRV1) was described in Leishmania guyanensis and Leishmania braziliensis strains. The aim of this study was to determine the prevalence distribution of LRV1 in Leishmania isolates in French Guiana given that, in this French overseas department, most Leishmania infections are due to these parasite species. The presence of the virus was observed in 74% of Leishmania spp. isolates, with a highest presence in the internal areas of the country. © The American Society of Tropical Medicine and Hygiene.

  3. Comparative analysis of carbohydrate residues in the midgut of phlebotomines (Diptera: Psychodidae) from colony and field populations from Amazon, Brazil.

    Science.gov (United States)

    de Oliveira, Davi Marcos Souza; da Silva, Bruno José Martins; de Sena, Chubert Bernardo Castro; Lima, José Aprígio Nunes; Vasconcelos Dos Santos, Thiago; Silveira, Fernando Tobias; Silva, Edilene Oliveira

    2016-09-01

    Leishmaniasis are worldwide diseases that occur in 98 countries including Brazil, transmitted by the bite of female phlebotomines during blood feeding. In Brazil it is known that some species of sand flies as Lutzomyia longipalpis sensun latum (vector of Leishmania infantum chagasi), Lutzomyia flaviscutellata (vector of Leishmania (Leishmania) amazonensis) and Lutzomyia antunesi [suspected vector of Leishmania (Viannia) lindenbergi] are incriminated of transmitting the parasite Leishmania for the vertebrate host. The phlebotomine-parasite is mediated by the attachment of the promastigote lipophosphoglycan (LPG) to the midgut epithelium. However, another mechanism that is LPG-independent and mediated by N-acetyl-galactosamine (GalNAc) seems to occur in some species of phlebotomines that are classified as permissive. The aim of this study was to characterize the carbohydrate residues that, probably, play a role in parasite attachment to the midgut of phlebotomine from colony and field populations from the Brazilian Amazonian region. We observed the presence of GalNAc, mannose, galactose and GlcNAc in all phlebotomine species. A binding assay between L. (L.) amazonensis and L. i.chagasi to the midguts of different species of phlebotomines was performed. The attachment of both Leishmania and vector species suggests the presence of GalNAc on the midgut surfaces. Thus, these results suggested that GalNAc is a possible binding sites of Leishmania in sand flies from the Brazilian Amazonian region. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Synthesis, characterization and study of activity inhibitory of new dialkylphosphorylhdrazones on the growth of trypanosomatids; Sintese, caracterizacao e estudo da atividade inibitoria de novas dialquilfosforilarilidrazonas sobre o crescimento de tripanossomatideos

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Andrea Janaina M.; Lima, Marco Edilson F. de; DaCosta, Joao Batista N., E-mail: dacosta@ufrrj.br [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Alves, Eliomara Sousa Sobral; Anjos, Danielle Oliveira dos; Vannier-Santos, Marcos Andre; Lanfredi-Rangel, Adriana [Fundacao Oswaldo Cruz, Salvador, BA (Brazil). Centro de Pesquisas Goncalo Moniz

    2011-07-01

    A new series of dialkylphosphorylhydrazones was synthesized through the condensation of aromatic aldehydes with different phosphorylhydrazines. All synthesized compounds were characterized by IR, {sup 1}H-NMR, {sup 13}C-NMR and {sup 31}P-NMR spectroscopies. The in vitro investigation of the activity of these compounds against Leishmania amazonensis promastigotes and epimastigotes of T. cruzi, showed an efficient inhibition of proliferation, at non toxic concentrations to mammalian cells. The results have shown some derivatives as potential antiparasitic agents against trypanosomatids. (author)

  5. Strychnos pseudoquina and Its Purified Compounds Present an Effective In Vitro Antileishmanial Activity

    Directory of Open Access Journals (Sweden)

    Paula Sousa Lage

    2013-01-01

    Full Text Available The development of new and cost-effective alternative therapeutic strategies to treat leishmaniasis has become a high priority. In the present study, the antileishmanial activity of Strychnos pseudoquina St. Hil. was investigated and pure compounds that presented this biological effect were isolated. An ethyl acetate extract was prepared, and it proved to be effective against Leishmania amazonensis. A bioactivity-guided fractionation was performed, and two flavonoids were identified, quercetin 3-O-methyl ether and strychnobiflavone, which presented an effective antileishmanial activity against L. amazonensis, and studies were extended to establish their minimum inhibitory concentrations (IC50, their leishmanicidal effects on the intra-macrophage Leishmania stage, as well as their cytotoxic effects on murine macrophages (CC50, and in O+ human red blood cells. The data presented in this study showed the potential of an ethyl acetate extract of S. pseudoquina, as well as two flavonoids purified from it, which can be used as a therapeutic alternative on its own, or in association with other drugs, to treat disease evoked by L. amazonensis.

  6. Detection and molecular identification of leishmania RNA virus (LRV) in Iranian Leishmania species.

    Science.gov (United States)

    Hajjaran, Homa; Mahdi, Maryam; Mohebali, Mehdi; Samimi-Rad, Katayoun; Ataei-Pirkooh, Angila; Kazemi-Rad, Elham; Naddaf, Saied Reza; Raoofian, Reza

    2016-12-01

    Leishmania RNA virus (LRV) was first detected in members of the subgenus Leishmania (Viannia), and later, the virulence and metastasis of the New World species were attributed to this virus. The data on the presence of LRV in Old World species are confined to Leishmania major and a few Leishmania aethiopica isolates. The aim of this study was to survey the presence of LRV in various Iranian Leishmania species originating from patients and animal reservoir hosts. Genomic nucleic acids were extracted from 50 cultured isolates belonging to the species Leishmania major, Leishmania tropica, and Leishmania infantum. A partial sequence of the viral RNA-dependent RNA polymerase (RdRp) gene was amplified, sequenced and compared with appropriate sequences from the GenBank database. We detected the virus in two parasite specimens: an isolate of L. infantum derived from a visceral leishmaniasis (VL) patient who was unresponsive to meglumine antimoniate treatment, and an L. major isolate originating from a great gerbil, Rhombomys opimus. The Iranian LRV sequences showed the highest similarities to an Old World L. major LRV2 and were genetically distant from LRV1 isolates detected in New World Leishmania parasites. We could not attribute treatment failure in VL patient to the presence of LRV due to the limited number of specimens analyzed. Further studies with inclusion of more clinical samples are required to elucidate the potential role of LRVs in pathogenesis or treatment failure of Old World leishmaniasis.

  7. AVALIAÇÃO DA ATIVIDADE LEISHMANICIDA IN VITRO DE EUGENIA UNIFLORA

    Directory of Open Access Journals (Sweden)

    Elaine Gimenez Guimarães

    2016-12-01

    Full Text Available As leishmanioses são um conjunto de doenças causadas por protozoários do gênero Leishmania, transmitidas por meio de hábitos hematófagos de fêmeas de dípteros infectados, pertencentes à subfamília Phlebotominae. É uma doença negligenciada e de grande relevância devido sua incidência e letalidade quando não tratada. O tratamento das leishmanioses é um obstáculo, devido à alta toxidade e efeitos adversos causados pelos fármacos disponíveis. Neste sentido, as plantas medicinais têm ganhado grande destaque na busca por fármacos que possam apresentar menos efeitos colaterais. Diante disso, este trabalho teve por objetivo avaliar atividade leishmanicida do extrato hidroalcoólico das folhas de Eugenia uniflora na espécie Leishmania amazonensis. Os valores de IC50 foram de 1,99 µg/mL, 1,64 µg/mL e 1,39 µg/mL nos tempos de 24, 48 e 72 horas, respectivamente. Os resultados demonstram que o extrato testado possui significativa atividade leishmanicida.

  8. High density of Leishmania major and rarity of other mammals' Leishmania in zoonotic cutaneous leishmaniasis foci, Iran.

    Science.gov (United States)

    Bordbar, Ali; Parvizi, Parviz

    2014-03-01

    Only Leishmania major is well known as a causative agent of zoonotic cutaneous leishmaniasis (ZCL) in Iran. Our objective was to find Leishmania parasites circulating in reservoir hosts, sand flies and human simultaneously. Sand flies, rodents and prepared smears of humans were sampled. DNA of Leishmania parasites was extracted, and two fragments of ITS-rDNA gene amplified by PCR. RFLP and sequencing were employed to identify Leishmania parasites. Leishmania major and L. turanica were identified unequivocally by targeting and sequencing ITS-rDNA from humans, rodents and sand flies. The new Leishmania species close to gerbilli (GenBank Accession Nos. EF413076; EF413087) was discovered only in sand flies. Based on parasite detection of ITS-rDNA in main and potential reservoir hosts and vectors and humans, we conclude that at least two Leishmania species are common in the Turkmen Sahra ZCL focus. Phylogenetic analysis proved that the new Leishmania is closely related to Leishmania mammal parasites (Leishmania major, Leishmania turanica, Leishmania gerbilli). Its role as a principal agent of ZCL is unknown because it was found only in sand flies. Our findings shed new light on the transmission cycles of several Leishmania parasites in sand flies, reservoir hosts and humans. © 2014 John Wiley & Sons Ltd.

  9. Effect of clinically approved HDAC inhibitors on Plasmodium, Leishmania and Schistosoma parasite growth.

    Science.gov (United States)

    Chua, Ming Jang; Arnold, Megan S J; Xu, Weijun; Lancelot, Julien; Lamotte, Suzanne; Späth, Gerald F; Prina, Eric; Pierce, Raymond J; Fairlie, David P; Skinner-Adams, Tina S; Andrews, Katherine T

    2017-04-01

    Malaria, schistosomiasis and leishmaniases are among the most prevalent tropical parasitic diseases and each requires new innovative treatments. Targeting essential parasite pathways, such as those that regulate gene expression and cell cycle progression, is a key strategy for discovering new drug leads. In this study, four clinically approved anti-cancer drugs (Vorinostat, Belinostat, Panobinostat and Romidepsin) that target histone/lysine deacetylase enzymes were examined for in vitro activity against Plasmodium knowlesi, Schistosoma mansoni, Leishmania amazonensis and L. donovani parasites and two for in vivo activity in a mouse malaria model. All four compounds were potent inhibitors of P. knowlesi malaria parasites (IC 50 9-370 nM), with belinostat, panobinostat and vorinostat having 8-45 fold selectivity for the parasite over human neonatal foreskin fibroblast (NFF) or human embryonic kidney (HEK 293) cells, while romidepsin was not selective. Each of the HDAC inhibitor drugs caused hyperacetylation of P. knowlesi histone H4. None of the drugs was active against Leishmania amastigote or promastigote parasites (IC 50  > 20 μM) or S. mansoni schistosomula (IC 50  > 10 μM), however romidepsin inhibited S. mansoni adult worm parings and egg production (IC 50 ∼10 μM). Modest in vivo activity was observed in P. berghei infected mice dosed orally with vorinostat or panobinostat (25 mg/kg twice daily for four days), with a significant reduction in parasitemia observed on days 4-7 and 4-10 after infection (P < 0.05), respectively. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Effect of clinically approved HDAC inhibitors on Plasmodium, Leishmania and Schistosoma parasite growth

    Directory of Open Access Journals (Sweden)

    Ming Jang Chua

    2017-04-01

    Full Text Available Malaria, schistosomiasis and leishmaniases are among the most prevalent tropical parasitic diseases and each requires new innovative treatments. Targeting essential parasite pathways, such as those that regulate gene expression and cell cycle progression, is a key strategy for discovering new drug leads. In this study, four clinically approved anti-cancer drugs (Vorinostat, Belinostat, Panobinostat and Romidepsin that target histone/lysine deacetylase enzymes were examined for in vitro activity against Plasmodium knowlesi, Schistosoma mansoni, Leishmania amazonensis and L. donovani parasites and two for in vivo activity in a mouse malaria model. All four compounds were potent inhibitors of P. knowlesi malaria parasites (IC50 9–370 nM, with belinostat, panobinostat and vorinostat having 8–45 fold selectivity for the parasite over human neonatal foreskin fibroblast (NFF or human embryonic kidney (HEK 293 cells, while romidepsin was not selective. Each of the HDAC inhibitor drugs caused hyperacetylation of P. knowlesi histone H4. None of the drugs was active against Leishmania amastigote or promastigote parasites (IC50 > 20 μM or S. mansoni schistosomula (IC50 > 10 μM, however romidepsin inhibited S. mansoni adult worm parings and egg production (IC50 ∼10 μM. Modest in vivo activity was observed in P. berghei infected mice dosed orally with vorinostat or panobinostat (25 mg/kg twice daily for four days, with a significant reduction in parasitemia observed on days 4–7 and 4–10 after infection (P < 0.05, respectively.

  11. Crovirin, a snake venom cysteine-rich secretory protein (CRISP with promising activity against Trypanosomes and Leishmania.

    Directory of Open Access Journals (Sweden)

    Camila M Adade

    2014-10-01

    Full Text Available The neglected human diseases caused by trypanosomatids are currently treated with toxic therapy with limited efficacy. In search for novel anti-trypanosomatid agents, we showed previously that the Crotalus viridis viridis (Cvv snake venom was active against infective forms of Trypanosoma cruzi. Here, we describe the purification of crovirin, a cysteine-rich secretory protein (CRISP from Cvv venom with promising activity against trypanosomes and Leishmania.Crude venom extract was loaded onto a reverse phase analytical (C8 column using a high performance liquid chromatographer. A linear gradient of water/acetonitrile with 0.1% trifluoroacetic acid was used. The peak containing the isolated protein (confirmed by SDS-PAGE and mass spectrometry was collected and its protein content was measured. T. cruzi trypomastigotes and amastigotes, L. amazonensis promastigotes and amastigotes and T. brucei rhodesiense procyclic and bloodstream trypomastigotes were challenged with crovirin, whose toxicity was tested against LLC-MK2 cells, peritoneal macrophages and isolated murine extensor digitorum longus muscle. We purified a single protein from Cvv venom corresponding, according to Nano-LC MS/MS sequencing, to a CRISP of 24,893.64 Da, henceforth referred to as crovirin. Human infective trypanosomatid forms, including intracellular amastigotes, were sensitive to crovirin, with low IC50 or LD50 values (1.10-2.38 µg/ml. A considerably higher concentration (20 µg/ml of crovirin was required to elicit only limited toxicity on mammalian cells.This is the first report of CRISP anti-protozoal activity, and suggests that other members of this family might have potential as drugs or drug leads for the development of novel agents against trypanosomatid-borne neglected diseases.

  12. First report of Heterorhabditis amazonensis from Venezuela and characterization of three populations

    Czech Academy of Sciences Publication Activity Database

    Morales, N.; Morales-Montero, P.; Půža, Vladimír; San-Blas, E.

    2016-01-01

    Roč. 48, č. 3 (2016), s. 139-147 ISSN 0022-300X Institutional support: RVO:60077344 Keywords : biogeography * entomopathogenic nematode * Heterorhabditis amazonensis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.087, year: 2016 http://journals.fcla.edu/jon/issue/view/4275

  13. Effects of nitro-heterocyclic derivatives against Leishmania (Leishmania) infantum promastigotes and intracellular amastigotes.

    Science.gov (United States)

    Petri e Silva, Simone Carolina Soares; Palace-Berl, Fanny; Tavares, Leoberto Costa; Soares, Sandra Regina Castro; Lindoso, José Angelo Lauletta

    2016-04-01

    Leishmaniasis is an overlooked tropical disease affecting approximately 1 million people in several countries. Clinical manifestation depends on the interaction between Leishmania and the host's immune response. Currently available treatment options for leishmaniasis are limited and induce severe side effects. In this research, we tested nitro-heterocyclic compounds (BSF series) as a new alternative against Leishmania. Its activity was measured in Leishmania (Leishmania) infantum promastigotes and intracellular amastigotes using MTT colorimetric assay. Additionally, we assessed the phosphatidylserine exposure by promastigotes, measured by flow cytometry, as well as nitric oxide production, measured by Griess' method. The nitro-heterocyclic compounds (BSF series) showed activity against L. (L.) infantum promastigotes, inducting the phosphatidylserine exposition by promastigotes, decreasing intracellular amastigotes and increasing oxide nitric production. The selectivity index was more prominent to Leishmania than to macrophages. Compared to amphotericin b, our compounds presented higher IC50, however the selectivity index was more specific to parasite than to amphotericin b. In conclusion, these nitro-heterocyclic compounds showed to be promising as an anti-Leishmania drug, in in vitro studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Identification of a RAC/AKT-like gene in Leishmania parasites as a putative therapeutic target in leishmaniasis.

    Science.gov (United States)

    Varela-M, Rubén E; Ochoa, Rodrigo; Muskus, Carlos E; Muro, Antonio; Mollinedo, Faustino

    2017-10-10

    Leishmaniasis is one of the world's most neglected diseases caused by at least 20 different species of the protozoan parasite Leishmania. Although new drugs have become recently available, current therapy for leishmaniasis is still unsatisfactory. A subgroup of serine/threonine protein kinases named as related to A and C protein kinases (RAC), or protein kinase B (PKB)/AKT, has been identified in several organisms including Trypanosoma cruzi parasites. PKB/AKT plays a critical role in mammalian cell signaling promoting cell survival and is a major drug target in cancer therapy. However, the role of protozoan parasitic PKB/AKT remains to be elucidated. We have found that anti-human AKT antibodies recognized a protein of about 57 kDa in Leishmania spp. parasites. Anti-human phospho-AKT(Thr308) antibodies identified a protein in extracts from Leishmania spp. that was upregulated following parasite exposure to stressful conditions, such as nutrient deprivation or heat shock. Incubation of AKT inhibitor X with Leishmania spp. promastigotes under stressful conditions or with Leishmania-infected macrophages led to parasite cell death. We have identified and cloned a novel gene from Leishmania donovani named Ld-RAC/AKT-like gene, encoding a 510-amino acid protein of approximately 57.6 kDa that shows a 26.5% identity with mammalian AKT1. Ld-RAC/AKT-like protein contains major mammalian PKB/AKT hallmarks, including the typical pleckstrin, protein kinase and AGC kinase domains. Unlike mammalian AKT that contains key phosphorylation sites at Thr308 and Ser473 in the activation loop and hydrophobic motif, respectively, Ld-RAC/AKT-like protein has a Thr residue in both motifs. By domain sequence comparison, we classified AKT proteins from different origins in four major subcategories that included different parasites. Our data suggest that Ld-RAC/AKT-like protein represents a Leishmania orthologue of mammalian AKT involved in parasite stress response and survival, and

  15. Evaluation of the leishmanicidal activity of plants used by Peruvian Chayahuita ethnic group.

    Science.gov (United States)

    Estevez, Y; Castillo, D; Pisango, M Tangoa; Arevalo, J; Rojas, R; Alban, J; Deharo, E; Bourdy, G; Sauvain, M

    2007-11-01

    A total of 27 ethanolic plant extracts from 27 species were screened for leishmanicidal activity in vitro against Leishmania amazonensis. Most of the selected species (19) are traditionally used by the Chayahuitas, an Amazonian Peruvian ethnic group, to treat skin affections and/or leishmaniasis. A colorimetric method based on the reduction of tetrazolium salt (MTT) was used to measure the viability of Leishmania amazonensis promastigote and amastigote stages. Only the leaves of two species of the Piperaceae family (Piper hispidum Sw., and Piper strigosum Trel.) showed good leishmanicidal activities (IC(50)Cycadaceae) showed low activity against amastigote stage (IC(50) around 50 microg/ml). Of those only Tabernaemontana sananho displayed also good activity on promastigotes (IC(50)<10 microg/ml). Results are discussed herein, in relation with the traditional use of the plants and compared with other data from the relevant literature.

  16. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA Induce Protective Immune Responses in Dogs.

    Directory of Open Access Journals (Sweden)

    Elodie Petitdidier

    2016-05-01

    Full Text Available Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA, from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA or its carboxy terminal part LaPSA-12S (Cter-rPSA, combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates.

  17. Extracellular Expression in Aspergillus niger of an Antibody Fused to Leishmania sp. Antigens.

    Science.gov (United States)

    Magaña-Ortíz, Denis; Fernández, Francisco; Loske, Achim M; Gómez-Lim, Miguel A

    2018-01-01

    Nucleoside hydrolase and sterol 24-c-methyltransferase, two antigenic proteins of Leishmania sp., were expressed in Aspergillus niger. Genetic transformation of conidia was achieved using underwater shock waves. scFv antibody addressed to DEC205, a receptor of dendritic cells, was fused to two proteins of Leishmania sp. Receptor 205 has a relevant role in the immune system in mammals; it can modulate T cell response to different antigens. Extracellular expression strategy of recombinant antibody was achieved using a fragment of native glucoamylase A (514 aa) as a carrier. Fermentations in shake flasks showed that the recombinant protein (104 kDa) was expressed and secreted only when maltose was used as carbon source; on the contrary, the expression was highly repressed in presence of xylose. Noteworthy, recombinant protein was secreted without glucoamylase-carrier and accumulation at intracellular level was not observed. The results presented here demonstrate the high value of Aspergillus niger as biotechnological platform for recombinant antibodies against Leishmania sp. at low cost. To the best of our knowledge, this is the first report about the recombinant expression of antigenic proteins of Leishmania sp. in filamentous fungi. The protein obtained can be used to explore novel strategies to induce immunity against Leishmania sp. or it can be employed in diagnostic kits to detect this neglected disease.

  18. Determinación de la producción de Öxido Nítrico en Macrófagos Activados J774.1 como respuesta al tamaño de la carga fagocítica de partículas de látex y Leishmania amazonensis Determination of Nitric Oxide Production in Activate Macrophages J774.1 as effect of Phagocitic Load Volume of Latex Beads and Leishmania amazonensis

    OpenAIRE

    Camargo Jiménez Maria Helena; Camacho Maria Marcela

    2000-01-01

    La leishmaniosis es una enfermedad parasitaria causada por el protozoario Leishmania. Cercade 12 millones de personas padecen esta enfermedad y 350 millones de personas están enriesgo de contraerla. Existe evidencia de que la infección por Leishmania amazonensisdisminuyela producción de óxido nítrico (NO) de macrófagos; se ha interpretado que este deterioroes inducido por el parásito. Esta investigación corrobora esta idea, pero contradice que seaexclusivo de la infección. En este trabajo, cu...

  19. Detection and characterization of Leishmania (Leishmania and Leishmania (Viannia by SYBR green-based real-time PCR and high resolution melt analysis targeting kinetoplast minicircle DNA.

    Directory of Open Access Journals (Sweden)

    Marcello Ceccarelli

    Full Text Available Leishmaniasis is a neglected disease with a broad clinical spectrum which includes asymptomatic infection. A thorough diagnosis, able to distinguish and quantify Leishmania parasites in a clinical sample, constitutes a key step in choosing an appropriate therapy, making an accurate prognosis and performing epidemiological studies. Several molecular techniques have been shown to be effective in the diagnosis of leishmaniasis. In particular, a number of PCR methods have been developed on various target DNA sequences including kinetoplast minicircle constant regions. The first aim of this study was to develop a SYBR green-based qPCR assay for Leishmania (Leishmania infantum detection and quantification, using kinetoplast minicircle constant region as target. To this end, two assays were compared: the first used previously published primer pairs (qPCR1, whereas the second used a nested primer pairs generating a shorter PCR product (qPCR2. The second aim of this study was to evaluate the possibility to discriminate among subgenera Leishmania (Leishmania and Leishmania (Viannia using the qPCR2 assay followed by melting or High Resolution Melt (HRM analysis. Both assays used in this study showed good sensitivity and specificity, and a good correlation with standard IFAT methods in 62 canine clinical samples. However, the qPCR2 assay allowed to discriminate between Leishmania (Leishmania and Leishmania (Viannia subgenera through melting or HRM analysis. In addition to developing assays, we investigated the number and genetic variability of kinetoplast minicircles in the Leishmania (L. infantum WHO international reference strain (MHOM/TN/80/IPT1, highlighting the presence of minicircle subclasses and sequence heterogeneity. Specifically, the kinetoplast minicircle number per cell was estimated to be 26,566±1,192, while the subclass of minicircles amplifiable by qPCR2 was estimated to be 1,263±115. This heterogeneity, also observed in canine clinical

  20. Plants used in the treatment of leishmanial ulcers due to Leishmania (Viannia braziliensis in an endemic area of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio França

    1996-06-01

    Full Text Available This paper records the plants used in the treatment of cutaneous leishmaniasis due to Leishmania (Viannia braziliensis (L(Vb among the rural population of a cocoa- producing coastal area of Bahia state, Brazil. An enquiry conducted among a hundred patients identified 49 plant species used to treat skin ulceration caused by this Leishmania species. The principal plants used are caju-branco (Anacardium occidentale - Anacardiaceae, used by 65% of the population, folha-fogo (Clidemia hirta - Melastomataceae 39%, alfavaca-grossa (Plectranthus amboinicus - Lamiaceae 33%, mastruz (Chenopodium ambrosioides - Chenopodiaceae 31%, erva-de-santa-maria (Solatium americanum - Solanaceae (25% and transagem (Plantago major - Plantaginaceae. 2%.Este trabalho relata as plantas usadas no tratamento da leishmaniose cutânea, causada por Leishmania (Viannia braziliensis (L(Vb, na população rural da faixa litorânea produtora de cacau do estado da Bahia, Brasil. Um inquérito realizado entre 100 pacientes, identificou 49 espécies de plantas usadas para tratar úlceras de pele causadas por esta espécie de Leishmânia. As principais plantas usadas foram o cajueiro-branco (Anacardium occidentale - Anacardiaceae usado por 65% da população, a folha-fogo (Clidemia hirta - Melastomataceae 39%, a alfavaca-grossa (Plectranthus amboinicus - Lamiaceae 33%, o mastruz (Chenopodium ambrosioides - henopodiaceae 31%, a erva-de-santa-maria (Solanum americanum - Solanaceae 25% e a transagem (Plantago major - Plantaginaceae 2%.

  1. Análise histomorfométrica da matriz extracelular do linfonodo poplíteo de cães naturalmente infectados por Leishmania (L. chagasi

    Directory of Open Access Journals (Sweden)

    Kris Régia J. Kondo

    2009-08-01

    Full Text Available Nas Américas, a leishmaniose visceral canina é causada por Leishmania (Leishmania chagasi, um protozoário intracelular obrigatório do sistema fagocítico mononuclear; as principais alterações histológicas associadas a essa doença ocorrem nos em órgãos linfóides. Apesar de o cão ser considerado o principal mantenedor e disseminador da leishmaniose no ambiente urbano, são escassos estudos dos aspectos histopatológicos e histomorfométricos, em cães naturalmente infectados com L. chagasi, que investiguem a interação entre o parasito e a matriz extracelular. Este estudo visou caracterizar e quantificar as alterações dos componentes celulares e da matriz extracelular (colágenos I e III do linfonodo poplíteo de 22 cães com infecção natural por L. chagasi detectada através da reação de imunofluorescência indireta (RIF e compará-las com as alterações encontradas no linfonodo poplíteo de 10 cães não-infectados, negativos na RIF e clinicamente saudáveis. Fragmentos dos linfonodos foram seccionados longitudinalmente, processados rotineiramente para exame histológico e corados por hematoxilina-eosina. Cortes adicionais do mesmo linfonodo incluídos em glicol metacrilato foram corados pelo azul de toluidina para histomorfometria. Linfonodos de cães infectados apresentaram linfadenopatia generalizada, aumento do tamanho e do número dos folículos linfóides, hipertrofia da cápsula e hiperplasia linfóide significativa. Nos linfonodos de cães do grupo infectado, a análise quantitativa de fibras colágenas mostrou significativo predomínio do colágeno I sobre o colágeno III. Esses resultados demonstram que cães infectados por L. chagasi apresentam degradação dos constituintes da matriz extracelular e conseqüente destruição do arcabouço linfóide, alterando a morfologia do órgão.In the Americas, canine visceral leishmaniasis is caused by Leishmania (Leishmania chagasi, an obligatory intracellular parasite of

  2. Leishmania (Leishmania infantum chagasi em canídeos silvestres mantidos em cativeiro, no Estado de Mato Grosso Leishmania (Leishmania infantum chagasi in wild canids kept in captivity in the State of Mato Grosso

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    Nely Pinheiro Souza

    2010-06-01

    Full Text Available INTRODUÇÃO: Leishmaniose visceral é uma zoonose que acomete diversos mamíferos tendo os canídeos domésticos como principais reservatórios em ambiente urbano. A presente nota descreve a infecção de canídeos silvestres por Leishmania (Leishmania infantum chagasi mantidos em cativeiro no Estado de Mato Grosso, Brasil. MÉTODOS: De seis raposas (Cerdocyon thous e um cachorro vinagre (Spheotos venaticus, foram coletadas amostras de pele, medula óssea e linfonodo para detecção e caracterização de Leishmania sp pela técnica de PCR-RFLP. RESULTADOS: Todos as animais pesquisados apresentaram-se positivos para Leishmania (L. infantum chagasi. CONCLUSÕES: Destaca-se a importância de monitoramento adequado dos mesmos, além do maior controle desta enfermidade já que estes animais estão em ambientes de recreação pública.INTRODUCTION: Visceral leishmaniasis is a zoonosis that affects many mammals, and domestic canids are the main reservoirs in urban environments. This note describes infection by Leishmania (Leishmania infantum chagasi among wild canids kept in captivity in the State of Mato Grosso, Brazil. METHODS: Skin, bone marrow and lymph node samples were collected from six crab-eating foxes (Cerdocyon thous and one bush dog (Spheotos venaticus, in order to detect and characterize Leishmania using the PCR-RFLP technique. RESULTS: All the animals studied were positive for Leishmania (L. infantum chagasi. CONCLUSIONS: This study highlights the importance of adequate monitoring of these animals, as well as greater control of this disease, given that these animals are in a public recreation environment.

  3. Leishmania mexicana: aspectos taxonómicos y rareza de la infección humana en Três Braços, Bahia, Brasil

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    César Augusto Cuba Cuba

    1984-09-01

    Full Text Available Del estúdio de 51 stocks de Leishmania aislados de pacientes humanos de leishmaniasis cutaneomucosa en Três Braços, Bahia, Brasil, los autores describen, en detalle, el análisis de los dos únicos stocks de L. mexicana, identificando uno de ellos como L. mexicana amazonensis. El otro aislado permanece en posición taxonómica no definida pues considerándosele como un miembro de L. mexicana, encuéntranse dificultades para su identificación subespecífica. Evaluan también los parâmetros biológicos e isoenzimáticos y discuten el papel de los anticuerpos monoclonales en la tipificación de éstos stocks. Los autores remarcan la rareza de la transmisión de parásitos del complejo L. mexicana en esta región, aun cuando estudien epidemiológicamente por mais de 8 anos la infección humana.

  4. Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts Comportamento de promastigoteas metacíclicos de Leishmania major durante o curso da infecção e da resposta imune em hospedeiros resistentes versus suscetíveis

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    Regina Coeli Cunha Dórea

    2003-11-01

    Full Text Available Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH in resistant versus susceptible inbred mice. Non-infective (procyclic promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible and C57BL/6 (resistant mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro

  5. Phenotypic characterization of Leishmania spp. causing cutaneous leishmaniasis in the lower Amazon region, western Pará state, Brazil, reveals a putative hybrid parasite, Leishmania (Viannia guyanensis × Leishmania (Viannia shawi shawi

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    Jennings Yara Lins

    2014-01-01

    Full Text Available We phenotypically characterized 43 leishmanial parasites from cutaneous leishmaniasis by isoenzyme electrophoresis and the indirect immunofluorescence antibody test (23 McAbs. Identifications revealed 11 (25.6% strains of Leishmania (V. braziliensis, 4 (9.3% of L. (V. shawi shawi, 7 (16.3% of L. (V. shawi santarensis, 6 (13.9% of L. (V. guyanensis and L. (V. lainsoni, 2 (4.7% of L. (L. amazonensis, and 7 (16.3% of a putative hybrid parasite, L. (V. guyanensis/L. (V. shawi shawi. McAbs detected three different serodemes of L. (V. braziliensis: I-7, II-1, and III-3 strains. Among the strains of L. (V. shawi we identified two populations: one (7 strains expressing the B19 epitope that was previously considered to be species-specific for L. (V. guyanensis. We have given this population sub-specific rank, naming it L. (V. s. santarensis. The other one (4 strains did not express the B19 epitope like the L. (V. shawi reference strain, which we now designate as L. (V. s. shawi. For the first time in the eastern Brazilian Amazon we register a putative hybrid parasite (7 strains, L. (V. guyanensis/L. (V. s. shawi, characterized by a new 6PGDH three-band profile at the level of L. (V. guyanensis. Its PGM profile, however, was very similar to that of L. (V. s. shawi. These results suggest that the lower Amazon region – western Pará state, Brazil, represents a biome where L. (V. guyanensis and L. (V. s. shawi exchange genetic information.

  6. Phenotypic characterization of Leishmania spp. causing cutaneous leishmaniasis in the lower Amazon region, western Pará state, Brazil, reveals a putative hybrid parasite, Leishmania (Viannia) guyanensis × Leishmania (Viannia) shawi shawi

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    Jennings, Yara Lins; de Souza, Adelson Alcimar Almeida; Ishikawa, Edna Aoba; Shaw, Jeffrey; Lainson, Ralph; Silveira, Fernando

    2014-01-01

    We phenotypically characterized 43 leishmanial parasites from cutaneous leishmaniasis by isoenzyme electrophoresis and the indirect immunofluorescence antibody test (23 McAbs). Identifications revealed 11 (25.6%) strains of Leishmania (V.) braziliensis, 4 (9.3%) of L. (V.) shawi shawi, 7 (16.3%) of L. (V.) shawi santarensis, 6 (13.9%) of L. (V.) guyanensis and L. (V.) lainsoni, 2 (4.7%) of L. (L.) amazonensis, and 7 (16.3%) of a putative hybrid parasite, L. (V.) guyanensis/L. (V.) shawi shawi. McAbs detected three different serodemes of L. (V.) braziliensis: I-7, II-1, and III-3 strains. Among the strains of L. (V.) shawi we identified two populations: one (7 strains) expressing the B19 epitope that was previously considered to be species-specific for L. (V.) guyanensis. We have given this population sub-specific rank, naming it L. (V.) s. santarensis. The other one (4 strains) did not express the B19 epitope like the L. (V.) shawi reference strain, which we now designate as L. (V.) s. shawi. For the first time in the eastern Brazilian Amazon we register a putative hybrid parasite (7 strains), L. (V.) guyanensis/L. (V.) s. shawi, characterized by a new 6PGDH three-band profile at the level of L. (V.) guyanensis. Its PGM profile, however, was very similar to that of L. (V.) s. shawi. These results suggest that the lower Amazon region – western Pará state, Brazil, represents a biome where L. (V.) guyanensis and L. (V.) s. shawi exchange genetic information. PMID:25083790

  7. First evidence of Leishmania infection in European brown hare (Lepus europaeus) in Greece: GIS analysis and phylogenetic position within the Leishmania spp.

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    Tsokana, C N; Sokos, C; Giannakopoulos, A; Mamuris, Z; Birtsas, P; Papaspyropoulos, K; Valiakos, G; Spyrou, V; Lefkaditis, M; Chatzopoulos, D C; Kantere, M; Manolakou, K; Touloudi, A; Burriel, A Rodi; Ferroglio, E; Hadjichristodoulou, C; Billinis, C

    2016-01-01

    Although the existence of a sylvatic transmission cycle of Leishmania spp., independent from the domestic cycle, has been proposed, data are scarce on Leishmania infection in wild mammals in Greece. In this study, we aimed to investigate the presence of Leishmania infection in the European brown hare in Greece, to infer the phylogenetic position of the Leishmania parasites detected in hares in Greece, and to identify any possible correlation between Leishmania infection in hares with environmental parameters, using the geographical information system (GIS). Spleen samples from 166 hares were tested by internal transcribed spacer-1 (ITS-1)-nested PCR for the detection of Leishmania DNA. Phylogenetic analysis was performed on Leishmania sequences from hares in Greece in conjunction with Leishmania sequences from dogs in Greece and 46 Leishmania sequences retrieved from GenBank. The Leishmania DNA prevalence in hares was found to be 23.49 % (95 % confidence interval (CI) 17.27-30.69). The phylogenetic analysis confirmed that the Leishmania sequences from hares in Greece belong in the Leishmania donovani complex. The widespread Leishmania infection in hares should be taken into consideration because under specific circumstances, this species can act as a reservoir host. This study suggests that the role of wild animals, including hares, in the epidemiology of Leishmania spp. in Greece deserves further elucidation.

  8. Dillapiole as antileishmanial agent: discovery, cytotoxic activity and preliminary SAR studies of dillapiole analogues.

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    Parise-Filho, Roberto; Pasqualoto, Kerly Fernanda Mesquita; Magri, Fátima Maria Motter; Ferreira, Adilson Kleber; da Silva, Bárbara Athayde Vaz Galvão; Damião, Mariana Celestina Frojuello Costa Bernstorff; Tavares, Maurício Temotheo; Azevedo, Ricardo Alexandre; Auada, Aline Vivian Vatti; Polli, Michelle Carneiro; Brandt, Carlos Alberto

    2012-12-01

    In this paper, the isolation of dillapiole (1) from Piper aduncum was reported as well as the semi-synthesis of two phenylpropanoid derivatives [di-hydrodillapiole (2), isodillapiole (3)], via reduction and isomerization reactions. Also, the compounds' molecular properties (structural, electronic, hydrophobic, and steric) were calculated and investigated to establish some preliminary structure-activity relationships (SAR). Compounds were evaluated for in vitro antileishmanial activity and cytotoxic effects on fibroblast cells. Compound 1 presented inhibitory activity against Leishmania amazonensis (IC(50)  = 69.3 µM) and Leishmania brasiliensis (IC(50)  = 59.4 µM) and induced cytotoxic effects on fibroblast cells mainly in high concentrations. Compounds 2 (IC(50)  = 99.9 µM for L. amazonensis and IC(50)  = 90.5 µM for L. braziliensis) and 3 (IC(50)  = 122.9 µM for L. amazonensis and IC(50)  = 109.8 µM for L. brasiliensis) were less active than dillapiole (1). Regarding the molecular properties, the conformational arrangement of the side chain, electronic features, and the hydrophilic/hydrophobic balance seem to be relevant for explaining the antileishmanial activity of dillapiole and its analogues. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Direct detection of Leishmania from clinical samples.

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    Waitumbi, John N; Bast, Joshua; Nyakoe, Nancy; Magiri, Charles; Quintana, Miguel; Takhampunya, Ratree; Schuster, Anthony L; Van de Wyngaerde, Marshall T; McAvin, James C; Coleman, Russell E

    2017-01-01

    The ability to rapidly and accurately diagnose leishmaniasis is a military priority. Testing was conducted to evaluate diagnostic sensitivity and specificity of field-expedient Leishmania genus and visceral Leishmania specific dual-fluorogenic, hydrolysis probe (TaqMan), polymerase chain reaction assays previously established for use in vector surveillance. Blood samples of patients with confirmed visceral leishmaniasis and controls without the disease from Baringo District, Kenya, were tested. Leishmania genus assay sensitivity was 100% (14/14) and specificity was 84% (16/19). Visceral Leishmania assay sensitivity was 93% (13/14) and specificity 80% (4/5). Cutaneous leishmaniasis (CL) skin scrapes of patients from Honduras were also evaluated. Leishmania genus assay sensitivity was 100% (10/10). Visceral Leishmania assay specificity was 100% (10/10) from cutaneous leishmaniasis samples; no fluorescence above background was reported. These results show promise in a rapid, sensitive, and specific method for Leishmania direct detection from clinical samples.

  10. Canine leishmaniosis caused by Leishmania major and Leishmania tropica: comparative findings and serology.

    Science.gov (United States)

    Baneth, Gad; Yasur-Landau, Daniel; Gilad, Matan; Nachum-Biala, Yaarit

    2017-03-13

    Infection and clinical disease associated with Leishmania major and Leishmania tropica, two common agents of human cutaneous leishmaniosis, have rarely been reported in dogs. This study describes dogs infected with these Leishmania spp. prevalent in the Middle East and North Africa, and compares the serological response of dogs infected with Leishmania infantum, L. major or L. tropica to whole promastigote antigen enzyme-linked immunosorbent assay (ELISA) of each species and to rK39 dipstick. Leishmania major infection in a 5-month-old male dog was associated with alopecic and ulcerative periocular and limb skin lesions which responded to allopurinol treatment. Infection was detected by skin and blood polymerase chain reaction (PCR) and confirmed by DNA sequencing but the dog was seronegative. Leishmania tropica infection was detected in a 3-month-old female dog co-infected with Babesia vogeli and Anaplasma platys and with no skin lesions. PCR and DNA sequencing of the blood and parasite culture were positive for L. tropica. Sera from 11 dogs infected with L. infantum, L. major or L. tropica were reactive with all three Leishmania spp. antigens except for sera from a dog with L. major infection. No significant differences were found between reactivity of dog sera to the antigen of the infecting species, or to the other Leishmania spp. antigens. Sera from dogs infected with L. infantum and L. tropica were positive with the rK39 antigen kit, while dogs with L. major infection were seronegative. Skin lesions in L. major infected dogs from this study and previous reports (n = 2) were ulcerative and located on the muzzle, feet and foot pads and not associated with generalized lymphadenomegaly and splenomegaly. In previous L. tropica infections, skin lesions were proliferative mucocutaneous in young dogs (n = 2), or associated with widespread dermatitis, lymphadenomegaly and splenomegaly in older dogs with similarity to L. infantum infection (n = 2). This

  11. Ocorrência de Leishmania spp. em felinos do município de Araçatuba, SP Occurrence de Leishmania spp. in domestic cats from Araçatuba, SP

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    Katia Denise Saraiva Bresciani

    2010-06-01

    Full Text Available Este trabalho teve como objetivo comparar a ocorrência de Leishmania spp. em gatos por dois métodos (citológico e sorológico, bem como associar a ocorrência deste protozoário com as variáveis sexo, idade e raça. Amostras séricas de 283 felinos domésticos foram testadas pela Reação de Imunofluorescência Indireta (RIFI, e o exame parasitológico direto de linfonodos também foi realizado para a verificação da positividade para Leishmania spp. Ocorrência de 0,7% (2/283 foi observada nos felinos examinados, por meio de imprint de linfonodos e nenhum animal apresentou títulos de anticorpos para Leishmania spp. As duas fêmeas positivas eram sem raça definida, sendo uma jovem e outra adulta. Por meio dos resultados obtidos, não foi constatada diferença estatisticamente significante em relação às variáveis sexo, raça e idade nos gatos desta pesquisa (p > 0,05. Ocorrência de Leishmania spp. nos gatos deste estudo foi baixa. Devido a esta baixa incidência sugere-se que estes não assumem importância epidemiológica na área do estudo.This study had the purpose to compare the occurrence of Leishmania spp. in felines through two methods (cytological and serological, as well as to associate the occurrence of this protozoan with the sex, age and breed variables. Serum samples from 283 domestic felines were processed by means of Indirect Immunofluorescence Reaction (IIR, and the direct parasitological test for linfonodes was also carried out in order to verify positivity for Leishmania spp. Occurrence of 0.7% (2/283 was observed in the tested felines by means of linfonode imprinting and no animal showed title of antibodies for Leishmania spp. The two positive females were mongrel, a young female and an adult female feline. From the obtained results, no statistically significant difference was observed as regards the sex, breed and age variables in this research (p > 0.05. Occurrence of Leishmania spp. in the cats of this study was

  12. The integrated endoplasmic reticulum stress response in Leishmania amazonensis macrophage infection: the role of X-box binding protein 1 transcription factor.

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    Dias-Teixeira, Karina Luiza; Calegari-Silva, Teresa Cristina; dos Santos, Guilherme R R M; Vitorino Dos Santos, José; Lima, Carolina; Medina, Jorge Mansur; Aktas, Bertal Huseyin; Lopes, Ulisses G

    2016-04-01

    Endoplasmic reticulum (ER) stress triggers the integrated ER-stress response (IERSR) that ensures cellular survival of ER stress and represents a primordial form of innate immunity. We investigated the role of IERSR duringLeishmania amazonensisinfection. Treatment of RAW 264.7 infected macrophages with the ER stress-inducing agent thapsigargin (TG; 1 μM) increasedL. amazonensisinfectivity in an IFN1-α receptor (IFNAR)-dependent manner. In Western blot assays, we showed thatL. amazonensisactivates the inositol-requiring enzyme (IRE1)/ X-box binding protein (XBP)-1-splicing arms of the IERSR in host cells. In chromatin immunoprecipitation (ChIP) assays, we showed an increased occupancy of enhancer and promoter sequences for theIfnbgene by XBP1 in infected RAW 264.7 cells. Knocking down XBP1 expression by transducing RAW 264.7 cells with the short hairpin XBP1 lentiviral vector significantly reduced the parasite proliferation associated with impaired translocation of phosphorylated IFN regulatory transcription factor (IRF)-3 to the nucleus and a decrease in IFN1-β expression. Knocking down XBP1 expression also increased NO concentration, as determined by Griess reaction and reduced the expression of antioxidant genes, such as heme oxygenase (HO)-1, that protect parasites from oxidative stress. We conclude thatL. amazonensisactivation of XBP1 plays a critical role in infection by protecting the parasites from oxidative stress and increasing IFN1-β expression.-Dias-Teixeira, K. L., Calegari-Silva, T. C., Dos Santos, G. R. R. M., Vitorino dos Santos, J., Lima, C., Medina, J. M., Aktas, B. H., Lopes, U. G. The integrated endoplasmic reticulum stress response inLeishmania amazonensismacrophage infection: the role of X-box binding protein 1 transcription factor. © FASEB.

  13. First evidence of autochthonous cases of Leishmania (Leishmania) infantum in horse (Equus caballus) in the Americas and mixed infection of Leishmania infantum and Leishmania (Viannia) braziliensis.

    Science.gov (United States)

    Soares, Isabel R; Silva, Soraia O; Moreira, Filipe Moraghi; Prado, Luan Gavião; Fantini, Priscila; Maranhão, Renata de Pino Albuquerque; da Silva Filho, José Monteiro; Melo, Maria Norma; Palhares, Maristela S

    2013-11-08

    This study reports the first evidence of infection by Leishmania infantum in Equus caballus in Americas and the first mixed infection of L. infantum/Leishmania braziliensis on this mammalian species in the world. The diagnoses was based on presence of parasites in lesions and bone marrow aspirates, their identification by using specific primers for L. infantum and L. braziliensis complexes and also serological methods IFAT and ELISA. The analysis of the PCR products suggested mixed infection in three animals. Further studies involving equine leishmaniasis are carrying out in order to clarify the dynamic of Leishmania sp. in this mammalian specie and their role in the transmission of those parasites in urban endemic area of Belo Horizonte, Minas Gerais State, Brazil. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Mucosal leishmaniasis due to Leishmania (Viannia braziliensis L(Vb in Três Braços, Bahia-Brazil

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    Philip Davis Marsden

    1994-06-01

    Full Text Available Brazilian mucosal leshmaniasis is briefly reviewed, emphasis being given to recent advances clinical management. Patients continue to occupy much hospital bed space and in some cases are notoriously difficult to treat. Indefinite follow up is recommended. Many aspects of the aetiology remain mysterious although Leishmania (Viannia braziliensis is the most common organism isolated. Perspectives for a more effective treatment, oral and cheap, are still remote.Neste trabalho, é feita uma breve revisão da leishmaniose mucosa existente no Brasil enfatizando os recentes avanços no tratamento clinico. Os pacientes frequentemente ocupam os leitos hospitalares e alguns casos são notoriamente difíceis de tratar. Recomenda-se um acompanhamento por tempo indefinido. Embora a Leishmania (Viannia braziliensis seja o microorganismo mais comumente isolado, muitos aspectos da etiologia permanecem obscuros. As perpectivas de um tratamento oral e barato são ainda remotas.

  15. Gluconeogenesis in Leishmania mexicana

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    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-01-01

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. PMID:25288791

  16. Synthesis and in vitro evaluation of new benzenesulfonamides as antileishmanial agents

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    Borges, Julio C.; Bernardino, Alice M.R.; Oliveira, Cesar D.; Pinheiro, Luiz C.S.; Marra, Roberta K.F., E-mail: juliusborges@yahoo.com.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Departamento de Quimica Organica. Programa de Pos-Graduacao em Quimica; Carvalho, Adriana V.; Canto-Cavalheiro, Marilene M.; Leon, Leonor L.; Genestra, Marcelo [Fundacao Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Lab. de Bioquimica de Tripanosomatideos; Castro, Helena C. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia. Programa de Pos-Graduacao em Ciencias e Biotecnologia; Wardell, Solange M.S.V. [CHEMSOL, Aberdeen, Scotland (United Kingdom); Wardell, James L. [Fundacao Oswaldo Cruz (Farmanguinhos/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto de Tecnologia em Farmacos; Amaral, Veronica F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia. Departamento de Imunobiologia

    2014-05-15

    This paper describes the synthesis and the antileishmanial activity of new pyrazolyl benzenesulfonamide derivatives. These were elucidated by spectrometric methods. Some compounds showed a significant in vitro activity against Leishmania amazonensis, highlighting the derivative 1e. These pyrazolyl benzenesulfonamide derivatives did not show any toxicity in murine macrophage. (author)

  17. Nitric oxide production by Peromyscus yucatanicus (Rodentia infected with Leishmania (Leishmania mexicana

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    Elsy Nalleli Loría-Cervera

    2013-04-01

    Full Text Available Peromyscus yucatanicus (Rodentia: Cricetidae is a primary reservoir of Leishmania (Leishmania mexicana (Kinetoplastida: Trypanosomatidae. Nitric oxide (NO generally plays a crucial role in the containment and elimination of Leishmania. The aim of this study was to determine the amount of NO produced by P. yucatanicus infected with L. (L. mexicana. Subclinical and clinical infections were established in P. yucatanicus through inoculation with 1 x 10 2 and 2.5 x 10 6 promastigotes, respectively. Peritoneal macrophages were cultured alone or co-cultured with lymphocytes with or without soluble Leishmania antigen. The level of NO production was determined using the Griess reaction. The amount of NO produced was significantly higher (p ≤ 0.0001 in co-cultured macrophages and lymphocytes than in macrophages cultured alone. No differences in NO production were found between P. yucatanicus with subclinical L. (L. mexicana infections and animals with clinical infections. These results support the hypothesis that the immunological mechanisms of NO production in P. yucatanicus are similar to those described in mouse models of leishmaniasis and, despite NO production, P. yucatanicus is unable to clear the parasite infection.

  18. Detection of Leishmania RNA virus in Leishmania parasites.

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    Haroun Zangger

    Full Text Available Patients suffering from cutaneous leishmaniasis (CL caused by New World Leishmania (Viannia species are at high risk of developing mucosal (ML or disseminated cutaneous leishmaniasis (DCL. After the formation of a primary skin lesion at the site of the bite by a Leishmania-infected sand fly, the infection can disseminate to form secondary lesions. This metastatic phenotype causes significant morbidity and is often associated with a hyper-inflammatory immune response leading to the destruction of nasopharyngeal tissues in ML, and appearance of nodules or numerous ulcerated skin lesions in DCL. Recently, we connected this aggressive phenotype to the presence of Leishmania RNA virus (LRV in strains of L. guyanensis, showing that LRV is responsible for elevated parasitaemia, destructive hyper-inflammation and an overall exacerbation of the disease. Further studies of this relationship and the distribution of LRVs in other Leishmania strains and species would benefit from improved methods of viral detection and quantitation, especially ones not dependent on prior knowledge of the viral sequence as LRVs show significant evolutionary divergence.This study reports various techniques, among which, the use of an anti-dsRNA monoclonal antibody (J2 stands out for its specific and quantitative recognition of dsRNA in a sequence-independent fashion. Applications of J2 include immunofluorescence, ELISA and dot blot: techniques complementing an arsenal of other detection tools, such as nucleic acid purification and quantitative real-time-PCR. We evaluate each method as well as demonstrate a successful LRV detection by the J2 antibody in several parasite strains, a freshly isolated patient sample and lesion biopsies of infected mice.We propose that refinements of these methods could be transferred to the field for use as a diagnostic tool in detecting the presence of LRV, and potentially assessing the LRV-related risk of complications in cutaneous leishmaniasis.

  19. Phylogenetic analysis of HSP70 and cyt b gene sequences for Chinese Leishmania isolates and ultrastructural characteristics of Chinese Leishmania sp.

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    Yuan, Dongmei; Qin, Hanxiao; Zhang, Jianguo; Liao, Lin; Chen, Qiwei; Chen, Dali; Chen, Jianping

    2017-02-01

    Leishmaniasis is a worldwide epidemic disease caused by the genus Leishmania, which is still endemic in the west and northwest areas of China. Some viewpoints of the traditional taxonomy of Chinese Leishmania have been challenged by recent phylogenetic researches based on different molecular markers. However, the taxonomic positions and phylogenetic relationships of Chinese Leishmania isolates remain controversial, which need for more data and further analysis. In this study, the heat shock protein 70 (HSP70) gene and cytochrome b (cyt b) gene were used for phylogenetic analysis of Chinese Leishmania isolates from patients, dogs, gerbils, and sand flies in different geographic origins. Besides, for the interesting Leishmania sp. in China, the ultrastructure of three Chinese Leishmania sp. strains (MHOM/CN/90/SC10H2, SD, GL) were observed by transmission electron microscopy. Bayesian trees from HSP70 and cyt b congruently indicated that the 14 Chinese Leishmania isolates belong to three Leishmania species including L. donovani complex, L. gerbilli, and L. (Sauroleishmania) sp. Their identity further confirmed that the undescribed Leishmania species causing visceral Leishmaniasis (VL) in China is closely related to L. tarentolae. The phylogenetic results from HSP70 also suggested the classification of subspecies within L. donovani complex: KXG-918, KXG-927, KXG-Liu, KXG-Xu, 9044, SC6, and KXG-65 belong to L. donovani; Cy, WenChuan, and 801 were proposed to be L. infantum. Through transmission electron microscopy, unexpectedly, the Golgi apparatus were not observed in SC10H2, SD, and GL, which was similar to previous reports of reptilian Leishmania. The statistical analysis of microtubule counts separated SC10H2, SD, and GL as one group from any other reference strain (L. donovani MHOM/IN/80/DD8; L. tropica MHOM/SU/74/K27; L. gerbilli MRHO/CN/60/GERBILLI). The ultrastructural characteristics of Leishmania sp. partly lend support to the phylogenetic inference that

  20. Geographic distribution and clinical description of leishmaniasis cases in Peru.

    Science.gov (United States)

    Lucas, C M; Franke, E D; Cachay, M I; Tejada, A; Cruz, M E; Kreutzer, R D; Barker, D C; McCann, S H; Watts, D M

    1998-08-01

    Studies were conducted from 1986 through 1993 to further define the geographic distribution and relative importance of different species of Leishmania as a cause of leishmaniasis in Peru. Patients with a clinical diagnosis of cutaneous and/or mucosal or diffuse cutaneous leishmaniasis were enrolled at the Naval Medical Research Institute Detachment (NAMRID) Laboratory in Lima, the Tropical Disease Clinic at San Marcos University Daniel A. Carrión, the Central Military Hospital, and a Ministry of Health hospital in Cusco, Peru. Clinical features, lesion aspirates, and biopsy tissue were obtained from each patient. All specimens were collected and assayed separately, including multiple specimens from some of the same patients for Leishmania parasites by inoculating aliquots of either aspirates or biopsy tissue suspensions onto Senekji's blood agar medium. Stocks of Leishmania isolates were used to prepare promastigotes to produce extracts for identifying the Leishmania species by the cellulose acetate electrophoresis enzyme technique. A total of 351 isolates of Leishmania were obtained from 350 patients who were infected primarily in the low and high jungle of at least 15 different Departments of Peru. Of the 351 isolates, 79% were identified as L. (V.) braziliensis, 7% as L. (V.) guyanensis, 10% as L. (V.) peruviana, 2% as L. (V.) lainsoni, and 1.7% as L. (L.) amazonensis. The clinical form of disease varied depending on the species of Leishmania, with L. (V.) braziliensis being associated most frequently with cutaneous, mucosal ulcers and mixed cutaneous and mucosal disease, and L. (V) peruviana, L. (V.) guyanensis, L. (V.) lainsoni with cutaneous lesions. Leishmania (L.) amazonensis was isolated from six patients, three with cutaneous lesions, one with mucosal lesions, and two with diffuse cutaneous lesions. Among all of the leishmaniasis cases, males were affected more frequently, and cases occurred among patients less than 10 to more than 51 years of age. These

  1. In vitro anti-leishmania evaluation of nickel complexes with a triazolopyrimidine derivative against Leishmania infantum and Leishmania braziliensis.

    Science.gov (United States)

    Ramírez-Macías, Inmaculada; Maldonado, Carmen R; Marín, Clotilde; Olmo, Francisco; Gutiérrez-Sánchez, Ramón; Rosales, María J; Quirós, Miguel; Salas, Juan M; Sánchez-Moreno, Manuel

    2012-07-01

    Studies on the anti-proliferative activity in vitro of seven ternary nickel (II) complexes with a triazolopyrimidine derivative and different aliphatic or aromatic amines as auxiliary ligands against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis have been carried out. These compounds are not toxic for the host cells and two of them are effective at lower concentrations than the reference drug used in the present study (Glucantime). In general, the in vitro growth rate of Leishmania spp. was reduced, its capacity to infect cells was negatively affected and the multiplication of the amastigotes decreased. Ultrastructural analysis and metabolism excretion studies were executed in order to propose a possible mechanism for the action of the assayed compounds. Our results show that the potential mechanism is at the level of organelles membranes, either by direct action on the microtubules or by their disorganization, leading to vacuolization, degradation and ultimately cell death. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Natural infection of bats with Leishmania in Ethiopia.

    Science.gov (United States)

    Kassahun, Aysheshm; Sadlova, Jovana; Benda, Petr; Kostalova, Tatiana; Warburg, Alon; Hailu, Asrat; Baneth, Gad; Volf, Petr; Votypka, Jan

    2015-10-01

    The leishmaniases, a group of diseases with a worldwide-distribution, are caused by different species of Leishmania parasites. Both cutaneous and visceral leishmaniasis remain important public health problems in Ethiopia. Epidemiological cycles of these protozoans involve various sand fly (Diptera: Psychodidae) vectors and mammalian hosts, including humans. In recent years, Leishmania infections in bats have been reported in the New World countries endemic to leishmaniasis. The aim of this study was to survey natural Leishmania infection in bats collected from various regions of Ethiopia. Total DNA was isolated from spleens of 163 bats belonging to 23 species and 18 genera. Leishmania infection was detected by real-time (RT) PCR targeting a kinetoplast (k) DNA and internal transcribed spacer one (ITS1) gene of the parasite. Detection was confirmed by sequencing of the PCR products. Leishmania kDNA was detected in eight (4.9%) bats; four of them had been captured in the Aba-Roba and Awash-Methara regions that are endemic for leishmaniasis, while the other four specimens originated from non-endemic localities of Metu, Bedele and Masha. Leishmania isolates from two bats were confirmed by ITS1 PCR to be Leishmania tropica and Leishmania major, isolated from two individual bats, Cardioderma cor and Nycteris hispida, respectively. These results represent the first confirmed observation of natural infection of bats with the Old World Leishmania. Hence, bats should be considered putative hosts of Leishmania spp. affecting humans with a significant role in the transmission. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Leishmania hijacking of the macrophage intracellular compartments.

    Science.gov (United States)

    Liévin-Le Moal, Vanessa; Loiseau, Philippe M

    2016-02-01

    Leishmania spp., transmitted to humans by the bite of the sandfly vector, are responsible for the three major forms of leishmaniasis, cutaneous, diffuse mucocutaneous and visceral. Leishmania spp. interact with membrane receptors of neutrophils and macrophages. In macrophages, the parasite is internalized within a parasitophorous vacuole and engages in a particular intracellular lifestyle in which the flagellated, motile Leishmania promastigote metacyclic form differentiates into non-motile, metacyclic amastigote form. This phenomenon is induced by Leishmania-triggered events leading to the fusion of the parasitophorous vacuole with vesicular members of the host cell endocytic pathway including recycling endosomes, late endosomes and the endoplasmic reticulum. Maturation of the parasitophorous vacuole leads to the intracellular proliferation of the Leishmania amastigote forms by acquisition of host cell nutrients while escaping host defense responses. © 2015 FEBS.

  4. Improvement of in vitro and in vivo antileishmanial activities of 2', 6'-dihydroxy-4'-methoxychalcone by entrapment in poly(D,L-lactide) nanoparticles.

    Science.gov (United States)

    Torres-Santos, E C; Rodrigues, J M; Moreira, D L; Kaplan, M A; Rossi-Bergmann, B

    1999-07-01

    The inhibition of intracellular Leishmania amazonensis growth by 2', 6'-dihydroxy-4'-methoxychalcone (DMC) isolated from Piper aduncum was further enhanced after encapsulation of DMC in polymeric nanoparticles. Encapsulated DMC also showed increased antileishmanial activity in infected BALB/c mice, as evidenced by significantly smaller lesions and fewer parasites in the lesions.

  5. Observações sobre calazar em Jacobina, Bahia. VI - Investigações sobre reservatórios silvestres e comensais

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    I. A. Sherlock

    1988-03-01

    Full Text Available Durante os anos de 1982 a 1986, a investigação sobre mamíferos comensais e silvestres, da periferia da cidade de Jacobina, Bahia, mostrou, ao lado do escasso número de exemplares, uma reduzida variedade específica dessa fauna. Capturou-se apenas 11 espécies, entre as quais, predominou o Didelphis albiventris, que abrangeu 44% dos 213 espécimens capturados. Entre os 193 com exames já concluídos, 84 eram exemplares de D. albiventris e 2 estavam infectados pela Leishmania donovani senso lato, 1 por L. mexicana amazonensis, 1 por L. braziliensis, subespécie e 3 por Trypanosoma cruzi Também foram observadas formas suspeitas de serem amastigotas de leishmanics, nos esfregaços de órgãos de 3 exemplares de Dasyprocta aguti, 1 Cercomys cunicularius - e 1 Oryzomys eliurus. 0 restante dos exemplares, inclusive 14 de Lycalopex vetulus, estava negativo para flagelados. Apesar de reforçado por outros indicadores epidemiológicos, como a predominância específica, a freqüência domiciliar, a atratividade para a vetora Lutzomyia longipalpis, e a concomitância com casos humanos nos mesmos locais, o índice de 2,3% de infecção natural do Didelphis albiventris, não autoriza a conclusão definitiva de ser o marsupial o mais importante reservatório natural da leishmaniose visceral em Jacobina.From 1982 to 1986, investigations on the natural infection with leishmanias of the sylvatic and commensal mammals were carried out around the city of Jacobina, Bahia, one of the oldest endemic foci of visceral leishmaniasis in Brazil. The species of Marsupialia Didelphis albiventris predominated, with the rate of 44%, over the total of 213 specimens belonging to only 11 different species of mammals collected there. Among the 84 specimens of D. albiventris examined, 2(2.3% were infected with Leishmania donovani sensu lato; 1 with L. mexicana amazonensis, 1 with L. braziliensis sub species, and 3 with Trypanosoma cruzi. Also, amastigote suspected bodies were

  6. Leishmania infantum and Leishmania braziliensis: differences and similarities to evade the innate immune system

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    Sarah Athayde Couto Falcão

    2016-08-01

    Full Text Available Visceral Leishmaniasis is a severe form of the disease, caused by Leishmania infantum in the New World. Patients present an anergic immune response that favors parasite establishment and spreading through tissues like bone marrow and liver. On the other hand, Leishmania braziliensis causes localized cutaneous lesions, which can be self healing in some individuals. Interactions between host and parasite are essential to understand disease pathogenesis and progression. In this context, dendritic cells (DCs act as essential bridges that connect innate and adaptive immune responses. In this way, the aim of this study was to compare the effects of these two Leishmania species, in some aspects of human dendritic cells biology to better understanding of the evasion mechanisms of Leishmania from host innate immune response. To do so, DCs were obtained from monocytes from whole peripheral blood’s healthy volunteers donors and infected with L. infantum or L. braziliensis for 24 hours. We observed similar rates of infection (around 40% as well as parasite burden for both Leishmania species. Concerning surface molecules, we observed that both parasites induced CD86 expression when DCs were infected for 24h. On the other hand, we detected a lower surface expression of CD209 in the presence of both L. braziliensis and L. infantum, but only the last one promoted the survival of dendritic cells after 24 hours. Therefore, DCs infected by both Leishmania species showed a higher expression of CD86 and a decrease of CD209 expression, suggesting that both enter DCs through CD209 molecule. However, only L. infantum had the ability to inhibit DC apoptotic death, as an evasion mechanism that enables its spreading to organs like bone marrow and liver. Lastly, L. braziliensis was more silent parasite, once it did not inhibit DC apoptosis in our in vitro model.

  7. Antigenic profile of heat-killed versus thimerosal-treated Leishmania major using sodium dodecyl sulfate-polyacrylamide gel electrophoresis

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    Reza Arjmand

    2015-01-01

    Full Text Available Background: Leishmania is a parasitic protozoan of trypanosomatidae family which causes a wide spectrum of diseases ranging from self-healing cutaneous lesions to deadly visceral forms. In endemic areas, field trials of different preparations of Leishmania total antigen were tested as leishmaniasis vaccine. Two preparations of killed Leishmania major were produced In Iran, which were heat-killed vaccine called autoclaved L. major (ALM and thimerosal-treated freeze-thawed vaccine called killed L. major (KLM. In this study, the protein content of both ALM and KLM were compared with that of freshly harvested intact L. major promastigotes using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Materials and Methods: L. major (MRHO/IR/75/ER from pre-infected Balb/c mice was isolated with modified Novy-MacNeal-Nicolle (NNN medium and then subcultured in liquid RPMI 1640 medium supplemented with fetal calf serum (FCS 20% for mass production. Two preparations of KLM and ALM were produced by Razi Vaccine and Serum Research Institute, Iran, under WHO/TDR supervision. Electrophoresis was performed by SDS-PAGE method and the gel was stained by Coomassie brilliant blue dye. The resultant unit bands were compared using standard molecular proteins. Results: Electrophoresis of the two preparations produced many bands from 10 kDa to 100 kDa. KLM bands were much like those of freshly harvested intact L. major. Conclusion: It is concluded that although there are similar bands in the three forms of Leishmania antigens, there are some variations which might be considered for identification and purification of protective immunogens in a total crude antigen, and detection of their stability is essential for the production and marketing of a putative vaccine.

  8. Medicinal plants from the Yanesha (Peru): evaluation of the leishmanicidal and antimalarial activity of selected extracts.

    Science.gov (United States)

    Valadeau, Céline; Pabon, Adriana; Deharo, Eric; Albán-Castillo, Joaquina; Estevez, Yannick; Lores, Fransis Augusto; Rojas, Rosario; Gamboa, Dionicia; Sauvain, Michel; Castillo, Denis; Bourdy, Geneviève

    2009-06-25

    Ninety-four ethanolic extracts of plants used medicinally by the Yanesha, an Amazonian Peruvian ethnic group, for affections related to leishmaniasis and malaria were screened in vitro against Leishmania amazonensis amastigotes and against a Plasmodium falciparum chloroquine resistant strain. The viability of Leishmania amazonensis amastigote stages was assessed by the reduction of tetrazolium salt (MTT) while the impact on Plasmodium falciparum was determined by measuring the incorporation of radio-labelled hypoxanthine. Six plant species displayed good activity against Plasmodium falciparum chloroquine resistant strain (IC(50) Piper aduncum L. and Piper sp.) and the leaves of Jacaranda copaia (Aubl.) D. Don (Bignoniaceae). Eight species displayed interesting leishmanicidal activities (IC50 < 10 microg/ml): Carica papaya L. (Caricaceae), Piper dennisii Trel (Piperaceae), Hedychium coronarium J. König (Zingiberaceae), Cestrum racemosum Ruiz & Pav. (Solanaceae), Renealmia alpinia (Rottb.) Zingiberaceae, Lantana sp. (Verbenaceae), Hyptis lacustris A. St.-Hil. ex Benth. (Lamiaceae) and Calea montana Klat. (Asteraceae). Most of them are used against skin affections by Yanesha people. Results are discussed herein, according to the traditional use of the plants and compared with data obtained from the literature.

  9. Study of cross-reactivity in serum samples from dogs positive for Leishmania sp., Babesia canis and Ehrlichia canis in enzyme-linked immunosorbent assay and indirect fluorescent antibody test Estudo da reatividade cruzada em amostras de soro de cães positivos para Leishmania sp., Babesia canis e Ehrlichia canis, pelo ensaio imunoenzimático indireto e pela reação de imunofluorescência indireta

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    Trícia Maria F. de Sousa Oliveira

    2008-03-01

    Full Text Available To verify the presence of cross-reaction among leishmaniosis, ehrlichiosis and babesiosis in serological diagnostics used in human visceral leishmaniasis control programs, serum samples from leishmaniasis endemic and non-endemic areas were collected and tested by Indirect Fluorescent Antibody (IFAT and Enzyme-linked immunosorbent assay (ELISA. All serum samples from endemic areas were positive for Leishmania sp., by ELISA and IFAT, 51% positive for Babesia canis and 43% for Ehrlichia canis by IFAT. None of the serum samples from non-endemic areas were positive for Leishmania sp., by IFAT, but 67% were positive for B. canis and 78% for E. canis using the same test. When tested by ELISA for Leishmania sp., four samples from non-endemic area were positive. These dogs were then located and no clinical signs, parasites or antibody was detected in new tests for a six month period. Only one of these 4 samples was positive for B. canis by IFAT and ELISA and three for E. canis by IFAT. The results of the work suggest a co-infection in the endemic area and no serological cross-reaction among these parasites by IFAT and ELISA.Para verificar a existência de reação cruzada entre leishmaniose visceral, erliquiose e babesiose, nos testes sorológicos utilizados em programas de controle da leishmaniose visceral humana, amostras de soro canino provenientes de áreas endêmicas e não endêmicas para essa enfermidade, foram testadas pela Reação de Imunofluorescência (RIFI e Ensaio imunoenzimático (ELISA. Todos os soros provenientes de área endêmica foram positivos para Leishmania sp pelo ELISA e RIFI, 51% para Babesia canis e 43% para Ehrlichia canis pela RIFI. Pela RIFI, nenhum dos soros provenientes de área não endêmica foi positivo para Leishmania sp, sendo 67% positivos para B. canis e 78% para E. canis pelo mesmo teste. Quando testados pelo ELISA para Leishmania sp., quatro soros da área não endêmica foram positivos. Os cães foram localizados

  10. Molecular identification of Leishmania species in Taybad district, Iran

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    Salehi Ghodratollah

    2014-09-01

    Full Text Available Objective: To identify Leishmania species in patients with cutaneous leishmaniasis in the city of Taybad in Razavi Khorasan Province from April 2012 to March 2013. Methods: Among 52 persons who referred to Health Center of Taybad with suspected skin lesions, stained slide smears of 35 patients showed positive result for Leishmania. Also polymerase chain reaction assay performed using specific kDNA primers. Data of patients were analyzed with SPSS. Results: Of 35 positive smears for Leishmania, 21 (60% belonged to males and 14 (40% belonged to females. Polymerase chain reaction bands were observed in all 35 samples of which 31 (88.6% samples showed Leishmania tropica and 4 (11.4% showed Leishmania major. The highest infected age group was 11-20 years old. Conclusions: Both anthroponotic cutaneous leishmaniasis and zoonotic cutaneous leishmaniasis are present in Taybad. Leishmania tropica is the dominant causative species for anthroponotic cutaneous leishmaniasis. Further study is recommended to discover probable reservoir and vector for Leishmania major in Taybad.

  11. Innate Immunity against Leishmania Infections

    Science.gov (United States)

    Gurung, Prajwal; Kanneganti, Thirumala-Devi

    2015-01-01

    Leishmaniasis is a major health problem that affects more than 300 million people throughout the world. The morbidity associated with the disease causes serious economic burden in Leishmania endemic regions. Despite the morbidity and economic burden associated with Leishmaniasis, this disease rarely gets noticed and is still categorized under neglected tropical diseases. The lack of research combined with the ability of Leishmania to evade immune recognition has rendered our efforts to design therapeutic treatments or vaccines challenging. Herein, we review the literature on Leishmania from innate immune perspective and discuss potential problems as well as solutions and future directions that could aid in identifying novel therapeutic targets to eliminate this parasite. PMID:26249747

  12. Clonal variation within a mucosal isolate derived from a patient with Leishmania (Viannia braziliensis infection Variação clonal de um isolado derivado de um paciente com infecção mucosa pela Leishmania (Viannia braziliensis

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    César Augusto Cuba-Cuba

    1991-10-01

    Full Text Available Three isolates over 5 years from a patient with persistent relapsing mucosal leishmaniasis due to Leishmania (Viannia braziliensis and 7 clones from one of these isolates were studied by zymodemes and scrodemes analysis. Results showed evidences of clonal phenotypic variation. Eight isoenzymes markers demonstrated clear differences on Cellulose Acetate (CA and thin starch gel electrophoresis. Also a panel of specific monoclonal antibodies showed such differences. Our observations provide additional evidence that Leishmania (Viannia braziliensis is composed by subpopulations of parasites with peculiar biochemical and antigenic characteristics.No transcurso de um período de 5 anos foram estudados 3 isolados de um paciente com leishmaniose mucosa recidivante causada pela Leishmania (Viannia braziliensis e 7 clones de um desses isolados. Este estudo foi feito pela análise dos serodemas e zimodemas. Os resultados indicaram a ocorrência de variações fenotípicas clonais. Oito marcadores isoenzimáticos demonstraram diferenças nos padrões eletroforéticos em Acetato de Celulose (AC, bem como em camada fina de amido. Da mesma forma foram consultadas diferenças em um painel de anticorpos monoclonais específicos e subespecíficos. Nossas observações indicam ainda que a Leishmania (Viannia braziliensis está composta por subpopulações de parasitas com características bioquímicas e antigênicas peculiares.

  13. Improvement of In Vitro and In Vivo Antileishmanial Activities of 2′,6′-Dihydroxy-4′-Methoxychalcone by Entrapment in Poly(d,l-Lactide) Nanoparticles

    Science.gov (United States)

    Torres-Santos, Eduardo Caio; Rodrigues, José M.; Moreira, Davyson L.; Kaplan, Maria Auxiliadora C.; Rossi-Bergmann, Bartira

    1999-01-01

    The inhibition of intracellular Leishmania amazonensis growth by 2′,6′-dihydroxy-4′-methoxychalcone (DMC) isolated from Piper aduncum was further enhanced after encapsulation of DMC in polymeric nanoparticles. Encapsulated DMC also showed increased antileishmanial activity in infected BALB/c mice, as evidenced by significantly smaller lesions and fewer parasites in the lesions. PMID:10390243

  14. In vitro cytocidal effects of the essential oil from Croton cajucara (red sacaca) and its major constituent 7- hydroxycalamenene against Leishmania chagasi

    Science.gov (United States)

    2013-01-01

    Background Visceral leishmaniasis is the most serious form of leishmaniasis and can be lethal if left untreated. Currently available treatments for these parasitic diseases are frequently associated to severe side effects. The leaves of Croton cajucara are used as an infusion in popular medicine to combat several diseases. Previous studies have demonstrated that the linalool-rich essential oil from C. cajucara (white sacaca) is extremely efficient against the tegumentary specie Leishmania amazonensis. In this study, we investigated the effects of the 7-hydroxycalamenene-rich essential oil from the leaves of C. cajucara (red sacaca) against Leishmania chagasi, as well as on the interaction of these parasites with host cells. Methods Promastigotes were treated with different concentrations of the essential oil for determination of its minimum inhibitory concentration (MIC). In addition, the effects of the essential oil on parasite ultrastructure were analyzed by transmission electron microscopy. To evaluate its efficacy against infected cells, mouse peritoneal macrophages infected with L. chagasi promastigotes were treated with the inhibitory and sub-inhibitory concentrations of the essential oil. Results The minimum inhibitory concentrations of the essential oil and its purified component 7-hydroxycalamenene against L. chagasi were 250 and 15.6 μg/mL, respectively. Transmission electron microscopy analysis revealed important nuclear and kinetoplastic alterations in L. chagasi promastigotes. Pre-treatment of macrophages and parasites with the essential oil reduced parasite/macrophage interaction by 52.8%, while it increased the production of nitric oxide by L. chagasi-infected macrophages by 80%. Conclusion These results indicate that the 7-hydroxycalamenene-rich essential oil from C. cajucara is a promising source of leishmanicidal compounds. PMID:24088644

  15. Phylogenomic reconstruction supports supercontinent origins for Leishmania.

    Science.gov (United States)

    Harkins, Kelly M; Schwartz, Rachel S; Cartwright, Reed A; Stone, Anne C

    2016-03-01

    Leishmania, a genus of parasites transmitted to human hosts and mammalian/reptilian reservoirs by an insect vector, is the causative agent of the human disease complex leishmaniasis. The evolutionary relationships within the genus Leishmania and its origins are the source of ongoing debate, reflected in conflicting phylogenetic and biogeographic reconstructions. This study employs a recently described bioinformatics method, SISRS, to identify over 200,000 informative sites across the genome from newly sequenced and publicly available Leishmania data. This dataset is used to reconstruct the evolutionary relationships of this genus. Additionally, we constructed a large multi-gene dataset, using it to reconstruct the phylogeny and estimate divergence dates for species. We conclude that the genus Leishmania evolved at least 90-100 million years ago, supporting a modified version of the Multiple Origins hypothesis that we call the Supercontinent hypothesis. According to this scenario, separate Leishmania clades emerged prior to, and during, the breakup of Gondwana. Additionally, we confirm that reptile-infecting Leishmania are derived from mammalian forms and that the species that infect porcupines and sloths form a clade long separated from other species. Finally, we firmly place the guinea-pig infecting species, Leishmaniaenriettii, the globally dispersed Leishmaniasiamensis, and the newly identified Australian species from a kangaroo, as sibling species whose distribution arises from the ancient connection between Australia, Antarctica, and South America. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Screening for Inhibitors of Essential Leishmania Glucose Transporters

    Science.gov (United States)

    2013-07-01

    Leishmania Glucose Transporters PRINCIPAL INVESTIGATOR: Scott M. Landfear, Ph.D. CONTRACTING ORGANIZATION: Oregon Health & Science...COVERED 1 July 2009- 30 June 2013 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Screening for Inhibitors of Essential Leishmania Glucose Transporters 5b...The objective of this project was to identify compounds that selectively inhibit the essential Leishmania glucose transporters and could hence serve

  17. Mapa del proteoma de parásitos de Leishmania Viannia a partir de electroforesis de geles de poliacramida en dos dimensiones y otras técnicas asociadas

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    Rafael Góngora

    2003-06-01

    Full Text Available En este estudio demostramos el potencial de la electroforesis en dos dimensiones (2DE como herramienta para la caracterización del proteoma de Leishmania (expresión proteica complementaria del genoma. Los proteomas por 2DE en el rango neutro (pH 5-7 de extractos solubles de promastigotes de Leishmania (Viannia guyanensis y Leishmania (Viannia panamensis fueron reproducibles usando tampón de lisis de urea y nonidet P-40. Con la tinción de azul de Coomassie y nitrato de plata se detectaron, con buena resolución, 800 y 1.500 puntos de proteínas, respectivamente. Entre las proteínas de referencia comunes, aisladas de los proteomas de las cepas estudiadas, se identificaron por medio de espectrometría de masa de péptidos (LC-ES-MS/MS y métodos bioinformáticos, proteínas de choque térmico, proteína ribosomal S12, proteína de membrana del cinetoplasto 11 y una proteína hipotética específica de Leishmania de 13 kDa con función desconocida. Por inmunoblot y utilizando un anticuerpo monoclonal, se detectaron específicamente las proteínas paraflagelar 1 y 2 de 81,4 kDa y 77,5 kDa, respectivamente. La expresión proteica diferencial encontrada en los distintos clones de parásitos fueron reproducibles al ser comparados por medio de un programa analizador de imágenes. Estos datos demuestran el poder de resolución del análisis de proteomas por 2DE. La producción y caracterización de mapas proteicos básicos de Leishmania con buena calidad constituye un paso esencial en los estudios proteómicos comparativos orientados a la identificación de factores moleculares involucrados en la resistencia a drogas, virulencia de parásitos y el descubrimiento de blancos para nuevas drogas y vacunas.

  18. Antileishmanial activity evaluation of adunchalcone, a new prenylated dihydrochalcone from Piper aduncum L.

    Science.gov (United States)

    Dal Picolo, Camilla R; Bezerra, Mariana P; Gomes, Kaio S; Passero, Luiz Felipe D; Laurenti, Marcia D; Martins, Euder Glendes A; Sartorelli, Patricia; Lago, João Henrique G

    2014-09-01

    Bioactivity-guided fractionation of EtOH extract from the leaves of Piper aduncum L. (Piperaceae) afforded a new dihydrochalcone, named adunchalcone. Its structure was elucidated on the basis of their spectroscopic data, primarily NMR and MS. Adunchalcone was evaluated against promastigote forms of Leishmania (L.) amazonensis, L. (V.) braziliensis, L. (V.) shawi, and L. (L.) chagasi and displayed 50% effective concentrations (EC50) of 11.03, 26.70, and 11.26 μM, as well as selective indexes of 4.86, 2.01, 4.76 and 0.50, respectively. This compound was also tested against intracellular forms of L. (L.) amazonensis, displaying weak activity, in comparison to reference drug amphotericin B. However, despite reduced effect of adunchalcone against amastigotes of L. (L.) amazonensis, this work opens the perspective to use this particular molecule as a scaffold for the design of novel and selective drug candidates for neglected diseases, mainly leishmaniasis. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Nematodes of Amazonian birds, with a description of Hoazinstrongylus amazonensis n.gen.n.sp. (Trichostrongylidae, Libyostrongylinae

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    R. Magalhães Pinto

    1985-06-01

    Full Text Available During recent studies of the parasites of birds from the Amazonian Regio, the following nematodes were recovered: Hoazinstrongylus amazonensis n.gen.n.sp. from Opisthocomus hoazin (Muller, 1776; Ascaridia columbae (Gmel., 1790 Travassos, 1913, from Leptotila r. rufaxilla (Richard & Bernard, 1712 representing a new host record; Inglisakis ibanezi Freitas, Vicente & Santos, 1969, Cyrnea (C. semilunaris (Molin, 1860 Seurat, 1914 and Thelazia digitata Travassos, 1918. A compelte description is restrained to the new genus and new species here proposed. The other known and well described species are listed and accounted.Durante recentes estudos dos parasitas de aves capturadas na Região Amazônica, foram identificadas as seguintes espécies de nematóides: Hoazinstrongylus amazonensis n.gen.n.sp, de Opisthocomus hoazin (Muller, 1776, Ascaridia columbae (Gmel., 1790 Travassos, 1912, de Leptotila r. rufaxilla (Richard & Bernard, 1712 que se constitui em um novo hospedeiro para a espécie, Inglisakis ibanezi Freitas, Vicente & Santos, 1969, Cyrnea (C. semilunaris (Molin, 1860 Seurat, 1914 e Thelazia digitata Travassos, 1918.

  20. Leishmania infections: Molecular targets and diagnosis.

    Science.gov (United States)

    Akhoundi, Mohammad; Downing, Tim; Votýpka, Jan; Kuhls, Katrin; Lukeš, Julius; Cannet, Arnaud; Ravel, Christophe; Marty, Pierre; Delaunay, Pascal; Kasbari, Mohamed; Granouillac, Bruno; Gradoni, Luigi; Sereno, Denis

    2017-10-01

    Progress in the diagnosis of leishmaniases depends on the development of effective methods and the discovery of suitable biomarkers. We propose firstly an update classification of Leishmania species and their synonymies. We demonstrate a global map highlighting the geography of known endemic Leishmania species pathogenic to humans. We summarize a complete list of techniques currently in use and discuss their advantages and limitations. The available data highlights the benefits of molecular markers in terms of their sensitivity and specificity to quantify variation from the subgeneric level to species complexes, (sub) species within complexes, and individual populations and infection foci. Each DNA-based detection method is supplied with a comprehensive description of markers and primers and proposal for a classification based on the role of each target and primer in the detection, identification and quantification of leishmaniasis infection. We outline a genome-wide map of genes informative for diagnosis that have been used for Leishmania genotyping. Furthermore, we propose a classification method based on the suitability of well-studied molecular markers for typing the 21 known Leishmania species pathogenic to humans. This can be applied to newly discovered species and to hybrid strains originating from inter-species crosses. Developing more effective and sensitive diagnostic methods and biomarkers is vital for enhancing Leishmania infection control programs. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Antileishmanial Activity of Aldonamides and N-Acyl-Diamine Derivatives

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    Elaine S. Coimbra

    2008-01-01

    Full Text Available A number of lipophilic N-acyl-diamines and aldonamides have been synthesized and tested for their in vitro antiproliferative activity against Leishmania amazonensis and L. chagasi. Ribonamides, having one amino group, displayed good to moderate inhibition of parasite growth. The best result was obtained for compounds 10 and 15 with IC50 against L. chagasi below 5 μM.

  2. Quantification of anti-Leishmania antibodies in saliva of dogs.

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    Cantos-Barreda, Ana; Escribano, Damián; Bernal, Luis J; Cerón, José J; Martínez-Subiela, Silvia

    2017-08-15

    Detection of serum anti-Leishmania antibodies by quantitative or qualitative techniques has been the most used method to diagnose Canine Leishmaniosis (CanL). Nevertheless, saliva may represent an alternative to blood because it is easy to collect, painless and non-invasive in comparison with serum. In this study, two time-resolved immunofluorometric assays (TR-IFMAs) for quantification of anti-Leishmania IgG2 and IgA antibodies in saliva were developed and validated and their ability to distinguish Leishmania-seronegative from seropositive dogs was evaluated. The analytical study was performed by evaluation of assay precision, sensitivity and accuracy. In addition, serum from 48 dogs (21 Leishmania-seropositive and 27 Leishmania-seronegative) were analyzed by TR-IFMAs. The assays were precise, with an intra- and inter-assay coefficients of variation lower than 11%, and showed high level of accuracy, as determined by linearity under dilution (R 2 =0.99) and recovery tests (>88.60%). Anti-Leishmania IgG2 antibodies in saliva were significantly higher in the seropositive group compared with the seronegative (pLeishmania IgA antibodies between both groups were observed. Furthermore, TR-IFMA for quantification of anti-Leishmania IgG2 antibodies in saliva showed higher differences between seropositive and seronegative dogs than the commercial assay used in serum. In conclusion, TR-IFMAs developed may be used to quantify anti-Leishmania IgG2 and IgA antibodies in canine saliva with an adequate precision, analytical sensitivity and accuracy. Quantification of anti-Leishmania IgG2 antibodies in saliva could be potentially used to evaluate the humoral response in CanL. However, IgA in saliva seemed not to have diagnostic value for this disease. For future studies, it would be desirable to evaluate the ability of the IgG2 assay to detect dogs with subclinical disease or with low antibody titers in serum and also to study the antibodies behaviour in saliva during the

  3. Detection of Leishmania infantum DNA in hamsters infested with ticks collected from naturally infected dogs

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    Valter dos Anjos Almeida

    2016-12-01

    Full Text Available ABSTRACT. Almeida V. dos A., da Hora T.N., Leça Júnior N.F., Carvalho F.S., da Silva A.L., Wenceslau A.A., Albuquerque G.R. & Silva F.L. Detection of Leishmania infantum DNA in hamsters infested with ticks collected from naturally infected dogs. [Detecção do DNA de Leishmania infantum em hamsters infestados com carrapatos coletados de cães naturalmente infectados.] Revista Brasileira de Medicina Veterinária, 38(4:329-333, 2016. Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz, Campus Soane Nazaré de Andrade, Hospital Veterinário, Km 16, Rodovia Jorge Amado, Ilhéus, BA 45662-900, Brasil. E-mail: fabiana.lessa@gmail.com The aim of this study was to investigate the role of Rhipicephalus sanguineus, the brown dog tick, in the transmission of Leishmania infantum. To accomplish this, we used 24 adult golden hamsters of both genders, and divided them into two groups: a control group (n = 4 and an experimental group (n = 20. The animals from the experimental group were infested with ticks obtained from dogs naturally infected with L. infantum. Hamsters of the control group were not infested and were maintained at the same conditions, as the infested animals. After three months of observation, animals were euthanized and they were posted to obtain samples of their blood, spleen, liver, lymph nodes, and skin. These samples were then processed by histopathology, immunohistochemistry, and polymerase chain reaction (PCR. Fourteen hamsters (70% of the experimental group tested PCR-positive for L. infantum DNA in samples of buffy coat. The results of this study indicated that R. sanguineus ticks can transmit some forms or parts of L. infantum to parasitized hamsters.

  4. Presence of Leishmania amastigotes in peritoneal fluid of a dog with leishmaniasis from Alagoas, Northeast Brazil Presença de formas amastigotas de Leishmania em fluido peritoneal de cão com leishmaniose proveniente de Alagoas, nordeste do Brasil

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    Filipe Dantas-Torres

    2006-08-01

    Full Text Available The goal of this short communication is to report the uncommon presence of intracellular amastigotes of Leishmania in peritoneal fluid of a dog with leishmaniasis from Alagoas State, Brazil. Physical examination of an adult male rottweiler suspected to be suffering of leishmaniasis revealed severe loss of weight, ascitis, splenomegaly, moderately enlarged lymph nodes, onychogryphosis, generalized alopecia, skin ulcers on the posterior limbs, and conjunctivitis. Samples of bone marrow, popliteal lymph node, skin ulcer, and peritoneal fluid were collected and smears of each sample were prepared and stained with hematoxylin and eosin. Numerous amastigotes were detected in bone marrow, popliteal lymph node, and skin ulcer smears. Smears of peritoneal fluid revealed the unusual presence of several free and intracellular amastigotes of Leishmania. Future studies are needed to determine whether the cytology of ascitic fluid represents a useful tool for diagnosis Leishmania infection in ascitic dogs, particularly in those living in areas where canine leishmaniasis is enzootic.O objetivo desta comunicação é descrever a presença incomum de formas amastigotas de Leishmania em fluido peritoneal de um cão com leishmaniose proveniente do Estado de Alagoas, nordeste do Brasil. O exame físico de um cão macho adulto da raça rottweiler, apresentando suspeita de leishmaniose, revelou perda de peso severa, esplenomegalia, linfonodos moderadamente aumentados, ascite, onicogrifose, alopecia generalizada, conjuntivite e presença de lesões cutâneas ulceradas localizadas nos membros posteriores. Foram coletadas amostras de medula óssea, linfonodo poplíteo, fluido peritoneal e úlcera cutânea. A partir das amostras, foram elaborados esfregaços, os quais foram corados pela hematoxilina e eosina. Inúmeras formas amastigotas foram detectadas na medula óssea, linfonodo poplíteo e úlcera cutânea. Esfregaços de fluido peritoneal revelaram a presença, n

  5. Cryopreservation of Leishmania Species in Manisa Province.

    Science.gov (United States)

    Çavuş, İbrahim; Ocak, Fulya; Kaya, Tuğba; Özbilgin, Ahmet

    2017-09-01

    It was aimed to assess the success of the cryopreservation process which is carried out in order to preserve the genetic material and the virulence of the Leishmania species that are an important health problem in our region. Leishmania tropica, L. infantum, L. major, and L. donovani strains in Novy-MacNeal-Nicolle (NNN) medium in MCBU were used. Promastigotes cultured in the NNN medium were transferred to RPMI 1640 medium; promastigotes in the logarithmic phase were washed three times with PBS, and 15% dimethylsulfoxide (DMSO) was added. Leishmania species were transferred to 12 separate tubes. The tubes were stored at -86°C for one night by placing them in Coolcell boxes. The tubes were transferred into a liquid nitrogen tank. One cryotube per Leishmania strain is thawed monthly and cultured in NNN medium. For the duration of study it was observed that each Leishmania isolate preserved 60-65% of their viability and entered the logarithmic phase on the 7th day following the inoculation in the NNN medium. Abnormalities in the structures and movements of the promastigotes were not observed in microscopic examinations. The following conclusions were made: cryopreservation is important for studies planned related to leishmaniasis and cryopreservation with DMSO is successful.

  6. MOLECULAR CHARACTERIZATION OF AMERICAN CUTANEOUS LEISHMANIASIS IN THE TRI‑BORDER AREA OF ASSIS BRASIL, ACRE STATE, BRAZIL

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    Carolina Bioni Garcia TELES

    2015-08-01

    Full Text Available SUMMARY In this study, Leishmaniaspecies were identified by Polymerase Chain Reaction (PCR. The epidemiology of patients suspected of having American Cutaneous Leishmaniasis in the municipality of Assis Brasil, Acre State, located in the Brazil/Peru/Bolivia triborder was also investigated. By PCR, the DNA of Leishmaniawas detected in 100% of the cases (37 samples and a PCR-Restriction Fragment Length Polymorphism (RFLP of the hsp 70gene identified the species in 32 samples: Leishmania (Viannia braziliensis (65.6% , L. (V. shawi (28.1% , L. (V. guyanensis (3.1% and mixed infection L. (V. guyanensis and L. (Leishmania amazonensis (3.1%This is the first report of L. (V. shawiand L. (L. amazonensis in Acre. The two predominant species were found in patients living in urban and rural areas. Most cases were found in males living in rural areas for at least three years and involved in rural work. This suggests, in most cases, a possible transmission of the disease from a rural/forest source, although some patients had not engaged in activities associated with permanence in forestall areas, which indicate a possible sandflies adaptation to the periurban setting.

  7. Prevalence and risk factors associated with Leishmania infection in Trang Province, southern Thailand.

    Science.gov (United States)

    Manomat, Jipada; Leelayoova, Saovanee; Bualert, Lertwut; Tan-Ariya, Peerapan; Siripattanapipong, Suradej; Mungthin, Mathirut; Naaglor, Tawee; Piyaraj, Phunlerd

    2017-11-01

    Autochthonous cutaneous and visceral leishmaniasis (VL) caused by Leishmania martiniquensis and Leishmania siamensis have been considered emerging infectious diseases in Thailand. The disease burden is significantly underestimated, especially the prevalence of Leishmania infection among HIV-positive patients. A cross-sectional study was conducted to determine the prevalence and risk factors associated with Leishmania infection among patients with HIV/AIDS living in Trang province, southern Thailand, between 2015 and 2016. Antibodies against Leishmania infection were assayed using the direct agglutination test (DAT). DNA of Leishmania was detected by ITS1-PCR using the buffy coat. Species of Leishmania were also identified. Of 724 participants, the prevalence of Leishmania infection was 25.1% (182/724) using either DAT or PCR assays. Seroprevalence of Leishmania infection was 18.5% (134/724), while Leishmania DNA detected by the PCR method was 8.4% (61/724). Of these, 24.9% (180/724) were asymptomatic, whereas 0.3% (2/724) were symptomatic VL and VL/CL (cutaneous leishmaniasis). At least five species were identified: L. siamensis, L. martiniquensis, L. donovani complex, L. lainsoni, and L. major. Multivariate analysis showed that CD4+ levels Leishmania infection. Those who were PCR positive for Leishmania DNA were significantly associated with a detectable viral load, whereas non-injection drug use (NIDU) and CD4+ levels Leishmania seropositivity. A magnitude of the prevalence of underreporting Leishmania infection among Thai patients with HIV was revealed in this study. Effective public health policy to prevent and control disease transmission is urgently needed.

  8. Detecção de DNA de Leishmania braziliensis em pacientes de leishmaniose tegumentar americana Detección de DNA de Leishmania braziliensis en pacientes de leishmaniose tegumentaria americana Detection of Leishmania braziliensis DNA in American tegumentary leishmaniasis patients

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    Leila Martins

    2010-06-01

    Full Text Available Foi realizado diagnóstico para leishmaniose tegumentar americana a partir de sangue de pacientes residentes em dois municípios endêmicos do estado de Pernambuco. O DNA de 119 amostras de sangue foi extraído e submetido a reação em cadeia da polimerase. Utilizaram-se primers do minicírculo do DNA do cinetoplasto (kDNA de Leishmania braziliensis, circulante em Pernambuco, cuja seqüência-alvo gera um fragmento de 750 pares de bases. No total 58 (48,7% indivíduos apresentaram amplificação positiva e 61 (51,3% negativa. Das amostras positivas para a PCR, 37 (≅ 64% pertenciam a indivíduos tratados e sem lesão. Conclui-se que a técnica de PCR é eficaz para identificar o DNA de leishmânia em material de biópsias e em sangue venoso.Fue realizado diagnóstico para leishmaniosis tegumentaria americana a partir de sangre de pacientes residentes en dos municipios endémicos del estado de Pernambuco (Noreste de Brasil. El DNA de 119 muestras de sangre fue extraído y sometido a la reacción en cadena de la polimerasa. Se utilizaron primers del minicírculo del DNA del cinetoplasto (kDNA de Leishmania braziliensis, circulante en Pernambuco, cuya secuencia blanco genera un fragmento de 750 pares de bases. En total 58 (48,7% individuos presentaron amplificación positiva y 61 (51,3% negativa. De las muestras positivas para la PCR, 37 (≅64% pertenecían a individuos tratados y sin lesión. Se concluyó que la técnica de la PCR es eficaz para identificar el DNA de Leishmania en material de biopsias y en sangre venosa.Diagnostic tests for American tegumentary leishmaniasis were performed on blood samples of patients living in two endemic municipalities in the state of Pernambuco, Northeastern Brazil. DNA was extracted from 119 samples and used as template for polymerase chain reaction (PCR analysis. The tests used primers specific for the kinetoplast mini-circle DNA (kDNA of Leishmania braziliensis, a species circulating in Pernambuco, which

  9. Human mixed infections of Leishmania spp. and Leishmania-Trypanosoma cruzi in a sub Andean Bolivian area: identification by polymerase chain reaction/hybridization and isoenzyme

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    B Bastrenta

    2003-03-01

    Full Text Available Parasites belonging to Leishmania braziliensis, Leishmania donovani, Leishmania mexicana complexes and Trypanosoma cruzi (clones 20 and 39 were searched in blood, lesions and strains collected from 28 patients with active cutaneous leishmaniasis and one patient with visceral leishmaniasis. PCR-hybridization with specific probes of Leishmania complexes (L. braziliensis, L. donovani and L. mexicana and T. cruzi clones was applied to the different DNA samples. Over 29 patients, 8 (27.6% presented a mixed infection Leishmania complex species, 17 (58.6% a mixed infection Leishmania-T. cruzi, and 4 (13.8% a multi Leishmania-T. cruzi infection. Several patients were infected by the two Bolivian major clones 20 and 39 of T. cruzi (44.8%. The L. braziliensis complex was more frequently detected in lesions than in blood and a reverse result was observed for L. mexicana complex. The polymerase chain reaction-hybridization design offers new arguments supporting the idea of an underestimated rate of visceral leishmanisis in Bolivia. Parasites were isolated by culture from the blood of two patients and lesions of 10 patients. The UPGMA (unweighted pair-group method with arithmetic averages dendrogram computed from Jaccard's distances obtained from 11 isoenzyme loci data confirmed the presence of the three Leishmania complexes and undoubtedly identified human infections by L. (V. braziliensis, L. (L. chagasi and L. (L. mexicana species. Additional evidence of parasite mixtures was visualized through mixed isoenzyme profiles, L. (V. braziliensis-L. (L. mexicana and Leishmania spp.-T. cruzi.The epidemiological profile in the studied area appeared more complex than currently known. This is the first report of parasitological evidence of Bolivian patients with trypanosomatidae multi infections and consequences on the diseases' control and patient treatments are discussed.

  10. Description of Leishmania (Leishmania forattinii sp. n., a new parasite infecting opossums and rodents in Brazil

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    Elizaide L. A. Yoshida

    1993-09-01

    Full Text Available A new parasite species of Leishmania is described, L. (Leishmania forattinii sp. n., which was isolated from a pooled triturate of liver and spleen of a opossum (Didelphis marsupialis aurita and from skin samples from a rodent (Proechmys iheringi denigratus, captured in primary forest on the Atlantic Cost of Brazil. Our results on the basis of biological and molecular criteria indicate that this taxonomically distinct parasite ias a new species of the L. mexicana complex, but closely related to L. (L. aristidesi Laison & shaw, 1979, as revelated by phenetic and phylogenetic numerical analyses of the enzyme data. L. forattinii was clearly distinguishable from other Leishmania species of the genus usisng enzyme electrophoresis, monoclonal antibodies, molecular karyotypes, analysis of restriction enzyme digestion patterns of kinetoplast DNA (kDNA, as well as the use of kDNA hybridization procedures.

  11. Optical tweezers force measurements to study parasites chemotaxis

    Science.gov (United States)

    de Thomaz, A. A.; Pozzo, L. Y.; Fontes, A.; Almeida, D. B.; Stahl, C. V.; Santos-Mallet, J. R.; Gomes, S. A. O.; Feder, D.; Ayres, D. C.; Giorgio, S.; Cesar, C. L.

    2009-07-01

    In this work, we propose a methodology to study microorganisms chemotaxis in real time using an Optical Tweezers system. Optical Tweezers allowed real time measurements of the force vectors, strength and direction, of living parasites under chemical or other kinds of gradients. This seems to be the ideal tool to perform observations of taxis response of cells and microorganisms with high sensitivity to capture instantaneous responses to a given stimulus. Forces involved in the movement of unicellular parasites are very small, in the femto-pico-Newton range, about the same order of magnitude of the forces generated in an Optical Tweezers. We applied this methodology to investigate the Leishmania amazonensis (L. amazonensis) and Trypanossoma cruzi (T. cruzi) under distinct situations.

  12. Role of pro-inflammatory cytokine IL-17 in Leishmania pathogenesis and in protective immunity by Leishmania vaccines.

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    Banerjee, Antara; Bhattacharya, Parna; Joshi, Amritanshu B; Ismail, Nevien; Dey, Ranadhir; Nakhasi, Hira L

    2016-11-01

    The clinical outcome of Leishmania pathogenesis ranges from active skin lesions to fatal visceral dissemination and severely impaired T cell immunity. It is well established that a strong Th1 immune response is protective against cutaneous forms of the disease, however a mixed Th1/Th2 response is most commonly observed against visceral infections as evident from previous studies. Aside from Th1/Th2 cytokines, the pro-inflammatory IL-17 cytokine family plays an important role in the clearance of intracellular pathogens. In Leishmania induced skin lesions, IL-17 produced by Th17 cells is shown to exacerbate the disease, suggesting a role in pathogenesis. However, a protective role for IL-17 is indicated by the expansion of IL-17 producing cells in vaccine-induced immunity. In human visceral leishmaniasis (VL) it has been demonstrated that IL-17 and IL-22 are associated with protection against re-exposure to Leishmania, which further suggests the involvement of IL-17 in vaccine induced protective immunity. Although there is no vaccine against any form of leishmaniasis, the development of genetically modified live attenuated parasites as vaccine candidates prove to be promising, as they successfully induce a robust protective immune response in various animal models. However, the role of IL-17 producing cells and Th17 cells in response to these vaccine candidates remains unexplored. In this article, we review the role of IL-17 in Leishmania pathogenesis and the potential impact on vaccine induced immunity, with a special focus on live attenuated Leishmania parasites. Published by Elsevier Inc.

  13. Leishmania Hijacks Myeloid Cells for Immune Escape

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    María Martínez-López

    2018-05-01

    Full Text Available Protozoan parasites of the Leishmania genus are the causative agents of leishmaniasis, a group of neglected tropical diseases whose clinical manifestations vary depending on the infectious Leishmania species but also on host factors. Recognition of the parasite by host myeloid immune cells is a key to trigger an effective Leishmania-specific immunity. However, the parasite is able to persist in host myeloid cells by evading, delaying and manipulating host immunity in order to escape host resistance and ensure its transmission. Neutrophils are first in infiltrating infection sites and could act either favoring or protecting against infection, depending on factors such as the genetic background of the host or the parasite species. Macrophages are the main host cells where the parasites grow and divide. However, macrophages are also the main effector population involved in parasite clearance. Parasite elimination by macrophages requires the priming and development of an effector Th1 adaptive immunity driven by specific subtypes of dendritic cells. Herein, we will provide a comprehensive outline of how myeloid cells regulate innate and adaptive immunity against Leishmania, and the mechanisms used by the parasites to promote their evasion and sabotage. Understanding the interactions between Leishmania and the host myeloid cells may lead to the development of new therapeutic approaches and improved vaccination to leishmaniases, an important worldwide health problem in which current therapeutic or preventive approaches are limited.

  14. In vivo and in vitro control of Leishmania mexicana due to garlic-induced NO production.

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    Gamboa-León, M R; Aranda-González, I; Mut-Martín, M; García-Miss, M R; Dumonteil, E

    2007-11-01

    Leishmania mexicana is the main causal agent of cutaneous leishmaniasis in the Yucatán peninsula in Mexico. Control of this disease is associated with a Th1-type immune response and garlic extract has been reported as a Th1 immunomodulator in BALB/c mice infected with Leishmania major. In this study, we investigated the effect of garlic extracts on L. mexicana infection in vivo and in vitro. Garlic extract reduced footpad lesions in L. mexicana-infected BALB/c mice by inducing IFN-gamma production from T cells. In vitro, garlic extract reduced macrophage infection through induction of nitric oxide (NO) production. Garlic extract may thus act on both T cells and macrophages to stimulate IFN-gamma production and NO synthesis for parasite killing. A 10- to 14-kDa fraction was identified as responsible for the in vitro effect of the whole extract and may lead to the identification of novel immunomodulating drugs and therapeutic alternatives for the treatment of leishmaniasis.

  15. Arginase activity of Leishmania isolated from patients with cutaneous leishmaniasis.

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    Badirzadeh, A; Taheri, T; Abedi-Astaneh, F; Taslimi, Y; Abdossamadi, Z; Montakhab-Yeganeh, H; Aghashahi, M; Niyyati, M; Rafati, S

    2017-09-01

    Cutaneous leishmaniasis (CL) is one of the most important vector-borne parasitic diseases, highly endemic in Iran, and its prevalence is increasing all over the country. Arginase (ARG) activity in isolated Leishmania parasites from CL patients is yet to be explored. This study aimed to compare the ARG activity of isolated Leishmania promastigotes from CL patients with a standard strain of Leishmania major and its influences on the disease pathogenesis. We recruited 16 confirmed CL patients from Qom Province, in central Iran; after detection of Leishmania species using PCR-RFLP, we assessed the levels of ARG in the isolated promastigotes and determined the parasites' growth rate. Only L. major was identified from CL patients. The level of ARG activity in the isolated Leishmania promastigotes from CL patients was significantly higher than that obtained from the standard strain of L. major. No significant correlations between ARG activity and lesion size, number or duration were observed; in contrast, a significant negative correlation was seen between ARG level and Leishmania' growth rate. The obtained results suggest that increased ARG expression and activity in the isolated Leishmania promastigotes might contribute to the higher parasite infectivity and play a major role in the pathogenicity of the CL. © 2017 John Wiley & Sons Ltd.

  16. Leishmania Surveillance and Diagnostic Capability in Support of the Joint Biological Agent Identification and Diagnostic System (JBAIDS) and Leishmania Vector Surveillance

    Science.gov (United States)

    2013-02-07

    01-10-09 to 07-02-13 ’+. I II L~ J.\\NU :::OU~ Ill L~ :la. l-UI’I I 11J.\\l- I NUIVI~~I1 LEISHMANIA SURVEILLANCE AND DIAGNOSTIC CAPABILITY IN None...SUPPORT OF THE JOINT BIOLOGICAL AGENT IDENTIFICATION AND :lD. l:JI1J.\\NI NUIVI~~I1 DIAGNOSTIC SYSTEM (JBAIDS) None . ./ LEISHMANIA VECTOR...Field Station at Kisumu completed project activities through a resource sharing arrangement with the 59th MDW. Testing of the Leishmania epidemiology

  17. Calcein+/PI- as an early apoptotic feature in Leishmania.

    Directory of Open Access Journals (Sweden)

    Louise Basmaciyan

    Full Text Available Although leishmaniases are responsible for high morbidity and mortality all over the world, no really satisfying treatment exists. Furthermore, the corresponding parasite Leishmania undergoes a very characteristic form of programmed cell death. Indeed, different stimuli can induce morphological and biochemical apoptotic-like features. However, the key proteins involved in mammal apoptosis, such as caspases and death receptors, are not encoded in the genome of this parasite. Currently, little is known about Leishmania apoptosis, notably owing to the lack of specific tools for programmed cell death analysis in these parasites. Furthermore, there is a need for a better understanding of Leishmania programmed cell death in order (i to better understand the role of apoptosis in unicellular organisms, (ii to better understand apoptosis in general through the study of an ancestral eukaryote, and (iii to identify new therapeutic targets against leishmaniases. To advance understanding of apoptosis in Leishmania, in this study we developed a new tool based on the quantification of calcein and propidium iodide by flow cytometry. This double labeling can be employed to distinguish early apoptosis, late apoptosis and necrosis in Leishmania live cells with a very simple and rapid assay. This paper should, therefore, be of interest for people working on Leishmania and related parasites.

  18. Calcein+/PI- as an early apoptotic feature in Leishmania.

    Science.gov (United States)

    Basmaciyan, Louise; Azas, Nadine; Casanova, Magali

    2017-01-01

    Although leishmaniases are responsible for high morbidity and mortality all over the world, no really satisfying treatment exists. Furthermore, the corresponding parasite Leishmania undergoes a very characteristic form of programmed cell death. Indeed, different stimuli can induce morphological and biochemical apoptotic-like features. However, the key proteins involved in mammal apoptosis, such as caspases and death receptors, are not encoded in the genome of this parasite. Currently, little is known about Leishmania apoptosis, notably owing to the lack of specific tools for programmed cell death analysis in these parasites. Furthermore, there is a need for a better understanding of Leishmania programmed cell death in order (i) to better understand the role of apoptosis in unicellular organisms, (ii) to better understand apoptosis in general through the study of an ancestral eukaryote, and (iii) to identify new therapeutic targets against leishmaniases. To advance understanding of apoptosis in Leishmania, in this study we developed a new tool based on the quantification of calcein and propidium iodide by flow cytometry. This double labeling can be employed to distinguish early apoptosis, late apoptosis and necrosis in Leishmania live cells with a very simple and rapid assay. This paper should, therefore, be of interest for people working on Leishmania and related parasites.

  19. FIRST REPORT OF CUTANEOUS LEISHMANIASIS CAUSED BY Leishmania (Leishmania infantum chagasi IN AN URBAN AREA OF RIO DE JANEIRO, BRAZIL

    Directory of Open Access Journals (Sweden)

    Marcelo Rosandiski LYRA

    2015-10-01

    Full Text Available SUMMARY American tegumentary leishmaniasis (ATL is an infectious disease caused by protozoa of the genus Leishmania, and transmitted by sandflies. In the state of Rio de Janeiro, almost all of the cases of American tegumentary leishmaniasis (ATL are caused by Leishmania (Viannia braziliensis, while cases of visceral leishmaniasis (VL are caused by Leishmania (Leishmania infantum chagasi. The resurgence of autochthonous VL cases in Rio de Janeiro is related to the geographic expansion of the vector Lutzomyia longipalpis and its ability to adapt to urban areas. We report the first case of leishmaniasis with exclusively cutaneous manifestations caused by L. (L. infantum chagasi in an urban area of Rio de Janeiro. An eighty-one-year-old woman presented three pleomorphic skin lesions that were not associated with systemic symptoms or visceromegalies. Multilocus enzyme electrophoresis identified L. (L. infantum chagasi, but direct smear and PCR of bone narrow were negative for Leishmania sp. (suggesting exclusively cutaneous involvement. We discuss the different dermatological presentations of viscerotropic leishmaniasis of the New and Old World, and the clinical and epidemiological importance of the case. Etiologic diagnosis of ATL based upon exclusive clinical criteria may lead to incorrect conclusions. We should be aware of the constant changes in epidemiological patterns related to leishmaniases.

  20. Estudo de flebotomíneos (Diptera, Psychodidae em área urbana do município de Bonito, Mato Grosso do Sul, Brasil Study of phlebotomines (Diptera, Psychodidae in the urban area of Bonito municipality, Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Vânia Lúcia Brandão Nunes

    2008-09-01

    Full Text Available O objetivo do trabalho foi identificar a fauna flebotomínea em áreas do perímetro urbano do município de Bonito, Mato Grosso do Sul, Brasil. O estudo foi desenvolvido de março de 2005 a fevereiro de 2006, em 17 ecótopos distribuídos em 12 locais, três no Centro e nove em diferentes bairros. As capturas foram realizadas quinzenalmente com armadilhas automáticas luminosas. Capturou-se 2.680 espécimes, 2.283 machos e 397 fêmeas, de 12 espécies, Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia corumbaensis, Evandromyia sallesi, Lutzomyia longipalpis, Micropygomyia acanthopharynx, Micropygomyia quinquefer, Nyssomyia whitmani, Psathyromyia aragaoi, Psathyromyia punctigeniculata e Psathyromyia shannoni. Lutzomyia longipalpis, vetora do agente da leishmaniose visceral americana, foi a espécie mais freqüente e a mais abundante, representando 93,5% dos flebotomíneos capturados e índice de abundância padronizado de 0,85. Com freqüência mais expressiva nos ecótopos próximos de galinheiro e de pocilga, esta espécie foi capturada em todos os meses do ano, com picos no verão, inverno e primavera. As demais espécies foram pouco freqüentes. Ressalta-se que a captura de Bichromomyia flaviscutellata, no intradomicilio e peridomicílio, nas proximidade de mata remanescente, tem grande significado epidemiológico uma vez que essa espécie é a principal vetora da Leishmania (Leishmania amazonensis, agente etiológico da leishmaniose cutânea difusa anérgica. Portanto, na área urbana de Bonito foram encontradas duas espécies que comprovadamente participam da transmissão de leishmanioses, Lutzomyia longipalpis e Bichromomyia flaviscutellata, ambas encontradas naturalmente infectadas pelos respectivos agentes.The objective was to identify the urban phlebotomine sandfly fauna of the Bonito municipality, Mato Grosso do Sul, Brazil. The captures of insects were undertaken fortnightly from March 2005 to

  1. Leishmaniasis cutánea zosteriforme causada por Leishmania (Viannia panamensis y Leishmania (Viannia braziliensis: reporte de tres casos

    Directory of Open Access Journals (Sweden)

    Camilo Andrés Morales

    2014-09-01

    Se presentan tres casos de leishmaniasis cutánea zosteriforme en los que se identificaron Leishmania panamensis y Leishmania braziliensis como especies infectantes. La sospecha epidemiológica derivada de la procedencia de los pacientes, así como la sospecha clínica a partir del reconocimiento de una presentación infrecuente de la enfermedad, permitieron hacer el diagnóstico.

  2. TRANSCRIPTIONAL INHIBITION OF INTERLEUKIN-12 PROMOTER ACTIVITY IN LEISHMANIA SPP.-INFECTED MACROPHAGES

    Science.gov (United States)

    Jayakumar, Asha; Widenmaier, Robyn; Ma, Xiaojing; McDowell, Mary Ann

    2009-01-01

    To establish and persist within a host, Leishmania spp. parasites delay the onset of cell-mediated immunity by suppressing interleukin-12 (IL-12) production from host macrophages. Although it is established that Leishmania spp.-infected macrophages have impaired IL-12 production, the mechanisms that account for this suppression remain to be completely elucidated. Using a luciferase reporter assay assessing IL-12 transcription, we report here that Leishmania major, Leishmania donovani, and Leishmania chagasi inhibit IL-12 transcription in response to interferon-gamma, lipopolysaccharide, and CD40 ligand and that Leishmania spp. lipophosphoglycan, phosphoglycans, and major surface protein are not necessary for inhibition. In addition, all the Leishmania spp. strains and life-cycle stages tested inhibited IL-12 promoter activity. Our data further reveal that autocrine-acting host factors play no role in the inhibitory response and that phagocytosis signaling is necessary for inhibition of IL-12. PMID:18372625

  3. Cell cycle-dependent changes in localization of a 210 k Da microtubule-interacting protein in Leishmania

    Czech Academy of Sciences Publication Activity Database

    Libusová, Lenka; Dráberová, Eduarda; Juliano, C.; Viklický, Vladimír; Fiori, P.; Cappuccinelli, P.; Dráber, Pavel

    2002-01-01

    Roč. 96, č. 4 (2002), s. 226-227 [Sigma-Aldrich konference mladých chemiků, biochemiků a molekulárních biologů. 22.05.2002-25.05.2002, Velké Meziříčí] R&D Projects: GA ČR GA304/00/0553; GA AV ČR IAA5052004 Keywords : Leishmania * cell cycle * microtubule Subject RIV: EB - Genetics ; Molecular Biology

  4. Natural Leishmania sp. reservoirs and phlebotomine sandfly food source identification in Ibitipoca State Park, Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Flávia Quaresma

    2012-06-01

    Full Text Available Leishmania spp are distributed throughout the world and different species are associated with varying degrees of disease severity. However, leishmaniasis is thought to be confined to areas of the world where its insect vectors, sandflies, are present. Phlebotomine sandflies obtain blood meals from a variety of wild and domestic animals and sometimes from humans. These vectors transmit Leishmania spp, the aetiological agent of leishmaniasis. Identification of sandfly blood meals has generally been performed using serological methods, although a few studies have used molecular procedures in artificially fed insects. In this study, cytochrome b gene (cytB polymerase chain reaction (PCR was performed in DNA samples isolated from 38 engorged Psychodopygus lloydi and the expected 359 bp fragment was identified from all of the samples. The amplified product was digested using restriction enzymes and analysed for restriction fragment length polymorphisms (RFLPs. We identified food sources for 23 females; 34.8% yielded a primate-specific banding profile and 26.1% and 39.1% showed banding patterns specific to birds or mixed restriction profiles (rodent/marsupial, human/bird, rodent/marsupial/human, respectively. The food sources of 15 flies could not be identified. Two female P. lloydi were determined to be infected by Leishmania using internal transcribed spacer 1 and heat shock protein 70 kDa PCR-RFLP. The two female sandflies, both of which fed on rodents/marsupials, were further characterised as infected with Leishmania (Viannia braziliensis. These results constitute an important step towards applying methodologies based on cytB amplification as a tool for identifying the food sources of female sandflies.

  5. Phylogenetic position of Leishmania isolates from Khyber Pakhtunkhwa province of Pakistan.

    Science.gov (United States)

    Khan, Nazma Habib; Messenger, Louisa A; Wahid, Sobia; Sutherland, Colin J

    2016-08-01

    Several species of the genus Leishmania are causative agents of cutaneous leishmaniasis in Pakistan. This study aimed to determine phylogenetic placement of Leishmania species causing cutaneous leishmaniasis in Khyber Pakhtunkhwa province, Pakistan (34 Leishmania tropica, 3 Leishmania infantum), in-relation to species from other geographical areas using gene sequences encoding cytochrome b (cytb) and internal transcribed spacer 2 (its2). Based on cytochrome b sequence analysis, L. tropica strains from Pakistan and other geographical regions were differentiated into two genotype groups, A and B. Within the province, five distinct L. tropica genotypes were recognized; two in group A, three in group B. Two L. infantum isolates from the province were closely associated with both Afro-Eurasian and American species of the Leishmania donovani complex, including Leishmania chagasi, L. infantum and L. donovani from Sudan and Ethiopia; while a third L. infantum isolate could not be differentiated from visceralizing Kenyan and Indian L. donovani. We observed apposite phylogenetic placement of CL-causing L. tropica and L. infantum from Khyber Pakhtunkhwa. Affinities ascribed to Leishmania spp. From the region are valuable in tracing potential importation of leishmaniasis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Erythema exsudativum multiforme after a Leishmania skin test

    NARCIS (Netherlands)

    Wind, Bas S.; Guimarães, Luiz H.; Machado, Paulo R. L.

    2014-01-01

    A 45-year-old otherwise healthy male from an endemic region for Leishmania braziliensis infection in Bahia, Brazil, presented with three erosive hemorrhagic infiltrated plaques on the left shin accompanied with lymphadenopathy in the groin since one month. A Leishmania skin test performed on the

  7. Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae, Phlebotominae) From Ecuador

    Science.gov (United States)

    Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio

    2017-01-01

    Abstract The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador. The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and “Leishmania sp. siamensis”. Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador. PMID:28981860

  8. Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae, Phlebotominae) From Ecuador.

    Science.gov (United States)

    Quiroga, Cristina; Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio

    2017-11-07

    The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador.The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and "Leishmania sp. siamensis". Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  9. The action of ionizing radiation on the morphology, physiology and growth of Leishmania Amazonensis, with evaluation of their immunogenic power in experimental models

    International Nuclear Information System (INIS)

    Bonetti, Franco Claudio

    2002-01-01

    Leishmaniasis is a disease which affects thousands of people in the Tropical regions around the world, is caused by a protozoan of the genus Leishmania spp., with urban and wild mammals acting as reservoirs. In the mammal host, the amastigote form of the parasite infects and multiplies into macrophages. Treatments for leishmaniasis have a high cost and are long lasting, frequently resulting in therapy interruption. This procedure culminates with a selection of resistant parasite strains, inducing tolerance to the therapy. Either the control of vectors or the mammal host are difficult due the social and economic implications. Thus, the search for alternatives treatments against these protozoans have been stimulated. The gamma radiation ( 60 CO) shown to be an efficient toll to kill these parasites maintaining their immunogenicity. Cellular viability, Electronically microscopy and Multiplex-PCR techniques showed that, after irradiation, the parasites had their growth inhibited by cytoplasmatic and nucleic material disorganisation, appointing the gamma radiation as important in terms of immunogens improvement. (author)

  10. Cell cycle-dependent changes in localization of a 210-kDa microtubule-interacting protein in .I.Leishmania./I..

    Czech Academy of Sciences Publication Activity Database

    Libusová, Lenka; Dráberová, Eduarda; Juliano, C.; Viklický, Vladimír; Fiori, P. L.; Cappuccinelli, P.; Dráber, Petr

    2001-01-01

    Roč. 266, č. 2 (2001), s. 270-278 ISSN 0014-4827 R&D Projects: GA ČR GA304/00/0553; GA AV ČR IAA5052004 Keywords : microtubule-associated proteins * Leishmania-antibody Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.096, year: 2001

  11. Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

    Science.gov (United States)

    Messlinger, Helena; Sebald, Heidi; Heger, Lukas; Dudziak, Diana; Bogdan, Christian; Schleicher, Ulrike

    2018-01-01

    Activated natural killer (NK) cells release interferon (IFN)-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani). When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis) were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL)-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs) of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells reduced the

  12. Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

    Directory of Open Access Journals (Sweden)

    Helena Messlinger

    2018-01-01

    Full Text Available Activated natural killer (NK cells release interferon (IFN-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani. When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells

  13. Analysis of kinetoplast cytochrome b gene of 16 Leishmania isolates from different foci of China: different species of Leishmania in China and their phylogenetic inference

    Science.gov (United States)

    2013-01-01

    Background Leishmania species belong to the family Trypanosomatidae and cause leishmaniasis, a geographically widespread disease that infects humans and other vertebrates. This disease remains endemic in China. Due to the large geographic area and complex ecological environment, the taxonomic position and phylogenetic relationship of Chinese Leishmania isolates remain uncertain. A recent internal transcribed spacer 1 and cytochrome oxidase II phylogeny of Chinese Leishmania isolates has challenged some aspects of their traditional taxonomy as well as cladistics hypotheses of their phylogeny. The current study was designed to provide further disease background and sequence analysis. Methods We systematically analyzed 50 cytochrome b (cyt b) gene sequences of 19 isolates (16 from China, 3 from other countries) sequenced after polymerase chain reaction (PCR) using a special primer for cyt b as well as 31 sequences downloaded from GenBank. After alignment, the data were analyzed using the maximum parsimony, Bayesian and netwok methods. Results Sequences of six haplotypes representing 10 Chinese isolates formed a monophyletic group and clustered with Leishmania tarentolae. The isolates GS1, GS7, XJ771 of this study from China clustered with other isolates of Leishmania donovani complex. The isolate JS1 was a sister to Leishmania tropica, which represented an L. tropica complex instead of clustering with L. donovani complex or with the other 10 Chinese isolates. The isolates KXG-2 and GS-GER20 formed a monophyletic group with Leishmania turanica from central Asia. In the different phylogenetic trees, all of the Chinese isolates occurred in at least four groups regardless of geographic distribution. Conclusions The undescribed Leishmania species of China, which are clearly causative agents of canine leishmaniasis and human visceral leishmaniasis and are related to Sauroleishmania, may have evolved from a common ancestral parasite that came from the Americas and may have

  14. Differentiation of Leishmania (Viannia) panamensis and Leishmania (V.) guyanensis using BccI for hsp70 PCR-RFLP.

    Science.gov (United States)

    Montalvo Alvarez, Ana Margarita; Nodarse, Jorge Fraga; Goodridge, Ivón Montano; Fidalgo, Lianet Monzote; Marin, Marcel; Van Der Auwera, Gert; Dujardin, Jean-Claude; Bernal, Iván Darío Velez; Muskus, Carlos

    2010-05-01

    Leishmania panamensis and Leishmania guyanensis are two species of the subgenus Viannia that are genetically very similar. Both parasites are usually associated with cutaneous leishmaniasis, but also have the potential to cause the mucocutaneous form of the disease. In addition, the study of foci and consequently the identification of vectors and probable reservoirs involved in transmission require a correct differentiation between both species, which is important at epidemiological level. We explored the possibility of identifying these species by using restriction fragment length polymorphisms (RFLP) in the gene coding for heat-shock protein 70 (hsp70). Previously, an hsp70 PCR-RFLP assay proved to be very effective in differentiating other Leishmania species when HaeIII is used as restriction enzyme. Based on hsp70 sequences analysis, BccI was found to generate species-specific fragments that can easily be recognized by agarose gel electrophoresis. Using the analysis of biopsies, scrapings, and parasite isolates previously grouped in a cluster comprising both L. panamensis and L. guyanensis, we showed that our approach allowed differentiation of both entities. This offers the possibility not only for identification of parasites in biological samples, but also to apply molecular epidemiology in certain countries of the New World, where several Leishmania species could coexist. Copyright 2009 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  15. Leishmanicidal and cytotoxic activity from plants used in Tacana traditional medicine (Bolivia).

    Science.gov (United States)

    Arévalo-Lopéz, Diandra; Nina, Nélida; Ticona, Juan C; Limachi, Ivan; Salamanca, Efrain; Udaeta, Enrique; Paredes, Crispin; Espinoza, Boris; Serato, Alcides; Garnica, David; Limachi, Abigail; Coaquira, Dayana; Salazar, Sarah; Flores, Ninoska; Sterner, Olov; Giménez, Alberto

    2018-04-24

    Thirty-eight Tacana medicinal plant species used to treat skin problems, including leishmania ulcers, skin infections, inflammation and wound healing, were collected in the community of Buena Vista, Bolivia, with the Tacana people. Twenty two species are documented for the first time as medicinal plants for this ethnic group living in the northern area of the Department of La Paz. To evaluate the leishmanicidal effect (IC 50 ) and cytotoxicity (LD 50 ) of the selected plants. To carry out bioguided studies on the active extracts. To assess the potential of Bolivian plant biodiversity associated with traditional knowledge in the discovery of alternative sources to fight leishmaniasis. Seventy three ethanol extracts were prepared from 38 species by maceration and were evaluated in vitro against promastigotes of Leishmania amazonensis and L. braziliensis. Active extracts (IC 50 ≤ 50 μg/mL) were fractionated by chromatography on Silica gel column and the fractions were assessed against the two Leishmania strains. The most active fractions and the crude extracts were evaluated against reference strains of L. amazonensis, L. braziliensis, L. aethiopica, two native strains (L. Lainsoni and L. braziliensis) and for cytotoxicity against HeLa cells. The chromatographic profile of the active fractions was obtained by reverse phase chromatography using HPLC. From the 73 extracts, 39 extracts (53.4%) were inactive and 34 showed activity. Thirteen species were sselected for bioguided studies. The crude extracts and their 36 fractions were evaluated against two Leishmania strains. The most active fraction were tested in a panel of five leishmania strains and for cytotoxicity. The Selective Index (SI = LD 50 /IC 50 ) was calculated, and were generally low. Retention time and UV spectra were recorded for the active fractions by HPLC-DAD using a reverse phase column. Profiles were very different from each other, showing the presence of different compounds. Bolivian traditional

  16. First molecular detection of Leishmania tarentolae-like DNA in Sergentomyia minuta in Spain.

    Science.gov (United States)

    Bravo-Barriga, Daniel; Parreira, Ricardo; Maia, Carla; Blanco-Ciudad, Juan; Afonso, Maria Odete; Frontera, Eva; Campino, Lenea; Pérez-Martín, Juan Enrique; Serrano Aguilera, Francisco Javier; Reina, David

    2016-03-01

    Phlebotomine sand flies (Diptera, Psychodidae) are vectors of multiple Leishmania species, among which Leishmania infantum stands out as a being frequently pathogenic to humans and dogs in Mediterranean countries. In this study, Sergentomyia minuta sand flies were collected using CDC miniature light traps in different 431 biotopes from Southwest Spain. A total of 114 females were tested for the presence of Leishmania DNA by targeting ITS-1 and cyt-B sequences by PCR. Leishmania DNA was detected in one S. minuta. Characterization of the obtained DNA sequences by phylogenetic analyses revealed close relatedness with Leishmania tarentolae Wenyon, 1921 as well as with both human and canine pathogenic strains of Asian origin (China), previously described as Leishmania sp. To our knowledge, this is the first report of phlebotomine sand flies naturally infected with L. tarentolae-like in Spain. The possible infection of sand flies with novel Leishmania species should be taken into consideration in epidemiological studies of vector species in areas where leishmaniosis is endemic.

  17. From genomes to vaccines: Leishmania as a model.

    Science.gov (United States)

    Almeida, Renata; Norrish, Alan; Levick, Mark; Vetrie, David; Freeman, Tom; Vilo, Jaak; Ivens, Alasdair; Lange, Uta; Stober, Carmel; McCann, Sharon; Blackwell, Jenefer M

    2002-01-01

    The 35 Mb genome of Leishmania should be sequenced by late 2002. It contains approximately 8500 genes that will probably translate into more than 10 000 proteins. In the laboratory we have been piloting strategies to try to harness the power of the genome-proteome for rapid screening of new vaccine candidate. To this end, microarray analysis of 1094 unique genes identified using an EST analysis of 2091 cDNA clones from spliced leader libraries prepared from different developmental stages of Leishmania has been employed. The plan was to identify amastigote-expressed genes that could be used in high-throughput DNA-vaccine screens to identify potential new vaccine candidates. Despite the lack of transcriptional regulation that polycistronic transcription in Leishmania dictates, the data provide evidence for a high level of post-transcriptional regulation of RNA abundance during the developmental cycle of promastigotes in culture and in lesion-derived amastigotes of Leishmania major. This has provided 147 candidates from the 1094 unique genes that are specifically upregulated in amastigotes and are being used in vaccine studies. Using DNA vaccination, it was demonstrated that pooling strategies can work to identify protective vaccines, but it was found that some potentially protective antigens are masked by other disease-exacerbatory antigens in the pool. A total of 100 new vaccine candidates are currently being tested separately and in pools to extend this analysis, and to facilitate retrospective bioinformatic analysis to develop predictive algorithms for sequences that constitute potentially protective antigens. We are also working with other members of the Leishmania Genome Network to determine whether RNA expression determined by microarray analyses parallels expression at the protein level. We believe we are making good progress in developing strategies that will allow rapid translation of the sequence of Leishmania into potential interventions for disease

  18. Asymptomatic dogs are highly competent to transmit Leishmania (Leishmania) infantum chagasi to the natural vector.

    Science.gov (United States)

    Laurenti, Márcia Dalastra; Rossi, Claudio Nazaretian; da Matta, Vânia Lúcia Ribeiro; Tomokane, Thaise Yumie; Corbett, Carlos Eduardo Pereira; Secundino, Nágila Francinete Costa; Pimenta, Paulo Filemon Paulocci; Marcondes, Mary

    2013-09-23

    We evaluated the ability of dogs naturally infected with Leishmania (Leishmania) infantum chagasi to transfer the parasite to the vector and the factors associated with transmission. Thirty-eight infected dogs were confirmed to be infected by direct observation of Leishmania in lymph node smears. Dogs were grouped according to external clinical signs and laboratory data into symptomatic (n=24) and asymptomatic (n=14) animals. All dogs were sedated and submitted to xenodiagnosis with F1-laboratory-reared Lutzomyia longipalpis. After blood digestion, sand flies were dissected and examined for the presence of promastigotes. Following canine euthanasia, fragments of skin, lymph nodes, and spleen were collected and processed using immunohistochemistry to evaluate tissue parasitism. Specific antibodies were detected using an enzyme-linked immunosorbent assay. Antibody levels were found to be higher in symptomatic dogs compared to asymptomatic dogs (p=0.0396). Both groups presented amastigotes in lymph nodes, while skin parasitism was observed in only 58.3% of symptomatic and in 35.7% of asymptomatic dogs. Parasites were visualized in the spleens of 66.7% and 71.4% of symptomatic and asymptomatic dogs, respectively. Parasite load varied from mild to intense, and was not significantly different between groups. All asymptomatic dogs except for one (93%) were competent to transmit Leishmania to the vector, including eight (61.5%) without skin parasitism. Sixteen symptomatic animals (67%) infected sand flies; six (37.5%) showed no amastigotes in the skin. Skin parasitism was not crucial for the ability to infect Lutzomyia longipalpis but the presence of Leishmania in lymph nodes was significantly related to a positive xenodiagnosis. Additionally, a higher proportion of infected vectors that fed on asymptomatic dogs was observed (p=0.0494). Clinical severity was inversely correlated with the infection rate of sand flies (p=0.027) and was directly correlated with antibody

  19. A comparison of molecular markers to detect Lutzomyia longipalpis naturally infected with Leishmania (Leishmania infantum

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    Kárita Cláudia Freitas-Lidani

    2014-07-01

    Full Text Available The aim of the present study was to detect natural infection by Leishmania (Leishmania infantum in Lutzomyia longipalpis captured in Barcarena, state of Pará, Brazil, through the use of three primer sets. With this approach, it is unnecessary to previously dissect the sandfly specimens. DNA of 280 Lu. longipalpis female specimens were extracted from the whole insects. PCR primers for kinetoplast minicircle DNA (kDNA, the mini-exon gene and the small subunit ribosomal RNA (SSU-rRNA gene of Leishmania were used, generating fragments of 400 bp, 780 bp and 603 bp, respectively. Infection by the parasite was found with the kDNA primer in 8.6% of the cases, with the mini-exon gene primer in 7.1% of the cases and with the SSU-rRNA gene primer in 5.3% of the cases. These data show the importance of polymerase chain reaction as a tool for investigating the molecular epidemiology of visceral leishmaniasis by estimating the risk of disease transmission in endemic areas, with the kDNA primer representing the most reliable marker for the parasite.

  20. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs.

    Science.gov (United States)

    Miura, Ryuichi; Kooriyama, Takanori; Yoneda, Misako; Takenaka, Akiko; Doki, Miho; Goto, Yasuyuki; Sanjoba, Chizu; Endo, Yasuyuki; Fujiyuki, Tomoko; Sugai, Akihiro; Tsukiyama-Kohara, Kyoko; Matsumoto, Yoshitsugu; Sato, Hiroki; Kai, Chieko

    2015-01-01

    Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV-LACK, rCDV-TSA, and rCDV-LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV-LACK showed markedly smaller nodules without ulceration. Although the rCDV-TSA- and rCDV-LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV-LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs.

  1. Experimental Acquisition, Development, and Transmission of Leishmania tropica by Phlebotomus duboscqi

    Science.gov (United States)

    2013-01-01

    ac ta t ropica Experimental acquisition, development, and transmission of Leishmania tropica by Phlebotomus duboscqi Hanafi A. Hanafi, El...August 2012 Accepted 2 September 2012 Available online 10 September 2012 Keywords: Phlebotomus duboscqi Leishmania tropica Transmission Vector...competency a b s t r a c t We report experimental infection and transmission of Leishmania tropica (Wright), by the blood-feeding sand

  2. The immunomodulatory effect of plant lectins: a review with emphasis on ArtinM properties.

    Science.gov (United States)

    Souza, Maria A; Carvalho, Fernanda C; Ruas, Luciana P; Ricci-Azevedo, Rafael; Roque-Barreira, Maria Cristina

    2013-10-01

    Advances in the glycobiology and immunology fields have provided many insights into the role of carbohydrate-protein interactions in the immune system. We aim to present a comprehensive review of the effects that some plant lectins exert as immunomodulatory agents, showing that they are able to positively modify the immune response to certain pathological conditions, such as cancer and infections. The present review comprises four main themes: (1) an overview of plant lectins that exert immunomodulatory effects and the mechanisms accounting for these activities; (2) general characteristics of the immunomodulatory lectin ArtinM from the seeds of Artocarpus heterophyllus; (3) activation of innate immunity cells by ArtinM and consequent induction of Th1 immunity; (4) resistance conferred by ArtinM administration in infections with intracellular pathogens, such as Leishmania (Leishmania) major, Leishmania (Leishmania) amazonensis, and Paracoccidioides brasiliensis. We believe that this review will be a valuable resource for more studies in this relatively neglected area of research, which has the potential to reveal carbohydrate targets for novel prophylactic and therapeutic strategies.

  3. First Cases of Cutaneous Leishmaniasis Caused by Leishmania (Viannia) naiffi Infection in Surinam

    NARCIS (Netherlands)

    van Thiel, Pieter-Paul A. M.; van Gool, Tom; Kager, Piet A.; Bart, Aldert

    2010-01-01

    Cutaneous leishmaniasis in Surinam is generally caused by infection by Leishmania guyanensis. We report three cases of infection with Leishmania (Viannia) naiffi, a Leishmania species not described from Surinam before. Treatment with pentamidine proved to be effective

  4. Genetic Diversity in Natural Populations of New World Leishmania

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    Cupolillo Elisa

    1998-01-01

    Full Text Available Our results have shown the wide diversity of parasites within New World Leishmania. Biochemical and molecular characterization of species within the genus has revealed that much of the population heterogeneity has a genetic basis. The source of genetic diversity among Leishmania appears to arise from predominantly asexual, clonal reproduction, although occasional bouts of sexual reproduction can not be ruled out. Genetic variation is extensive with some clones widely distributed and others seemingly unique and localized to a particular endemic focus. Epidemiological studies of leishmaniasis has been directed to the ecology and dynamics of transmission of Leishmania species/variants, particularly in localized areas. Future research using molecular techniques should aim to identify and follow Leishmania types in nature and correlate genetic typing with important clinical characteristics such as virulence, pathogenicity, drug resistance and antigenic variation. The epidemiological significance of such variation not only has important implications for the control of the leishmaniases, but would also help to elucidate the evolutionary biology of the causative agents.

  5. Screening For Inhibitors Of Essential Leishmania Glucose Transporters

    Science.gov (United States)

    2011-07-01

    parasite life cycle and, unlike he amastigote form that lives inside mammalian macrophages, s viable provided that an alternative energy source such as pro...glucose transporters havebeenvalidated asnewdrug targets for proto- zoan parasites including Plasmodium falciparum, Leishmania mexicana and Trypanosoma...such as Leishmania species, Trypanosoma rucei, and Plasmodium falciparum, the causative agents of leish- aniasis, African sleeping sickness, and malaria

  6. Leishmania (Leishmania mexicana en el corregimiento de San Matías, municipio de Gómez Plata, Antioquia, Colombia

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    Diana Sierra

    2006-10-01

    Full Text Available Introducción. La leishmaniaisis es una enfermedad encontrada en focos naturales de infección donde están presentes insectos vectores y mamíferos reservorios deLeishmania. Objetivo. Registrar por primera vez la presencia de Leishmania (Leishmania mexicana Biagi, 1953, en el corregimiento de San Matías, municipio de Gómez Plata, departamento de Antioquia. Materiales y métodos. La especie fue aislada de un paciente con leishmaniasis cutánea localizada e identificada por la técnica de Inmunofluorescencia utilizando anticuerpos monoclonales específicos de especie y electroforesis de enzimas . Resultados y conclusión. Su perfil isoenzimático similar al de las cepas de referencia L. (L. mexicana (MNCY/BZ/62/M379 y L. (L. mexicana (MHOM/BE/82/BEL21, permitió concluír que la especie aislada del paciente es L. (L. mexicana.

  7. Humoral and In Vivo Cellular Immunity against the Raw Insect-Derived Recombinant Leishmania infantum Antigens KMPII, TRYP, LACK, and papLe22 in Dogs from an Endemic Area

    Science.gov (United States)

    Todolí, Felicitat; Solano-Gallego, Laia; de Juan, Rafael; Morell, Pere; del Carmen Núñez, Maria; Lasa, Rodrigo; Gómez-Sebastián, Silvia; Escribano, José M.; Alberola, Jordi; Rodríguez-Cortés, Alhelí

    2010-01-01

    Leishmania infantum causes visceral leishmaniasis, a severe zoonotic and systemic disease that is fatal if left untreated. Identification of the antigens involved in Leishmania-specific protective immune response is a research priority for the development of effective control measures. For this purpose, we evaluated, in 27 dogs from an enzootic zone, specific humoral and cellular immune response by delayed-type hypersensitivity (DTH) skin test both against total L. infantum antigen and the raw Trichoplusia ni insect-derived kinetoplastid membrane protein-11 (rKMPII), tryparedoxin peroxidase (rTRYP), Leishmania homologue of receptors for activated C kinase (rLACK), and 22-kDa potentially aggravating protein of Leishmania (rpapLe22) antigens from this parasite. rTRYP induced the highest number of positive DTH responses (55% of leishmanin skin test [LST]-positive dogs), showing that TRYP antigen is an important T cell immunogen, and it could be a promising vaccine candidate against this disease. When TRYP-DTH and KMPII-DTH tests were evaluated in parallel, 82% of LST-positive dogs were detected, suggesting that both antigens could be considered as components of a standardized DTH immunodiagnostic tool for dogs. PMID:21118936

  8. Molecular crosstalks in Leishmania-sandfly-host relationships

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    Volf P.

    2008-09-01

    Full Text Available Sandflies (Diptera: Phlebotominae are vectors of Leishmania parasites, causative agents of important human and animal diseases with diverse manifestations. This review summarizes present knowledge about the vectorial part of Leishmania life cycle and parasite transmission to the vertebrate host. Particularly, it focuses on molecules that determine the establishment of parasite infection in sandfly midgut. It describes the concept of specific versus permissive sandfly vectors, explains the epidemiological consequences of broad susceptibility of permissive sandflies and demonstrates that genetic exchange may positively affect Leishmania fitness in the vector. Last but not least, the review describes recent knowledge about circulating antibodies produced by hosts in response to sandfly bites. Studies on specificity and kinetics of antibody response revealed that anti-saliva IgG could be used as a marker of host exposure to sandflies, i.e. as a useful tool for evaluation of vector control.

  9. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs.

    Directory of Open Access Journals (Sweden)

    Ryuichi Miura

    Full Text Available Canine distemper virus (CDV vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV-LACK, rCDV-TSA, and rCDV-LmSTI1, respectively. Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV-LACK showed markedly smaller nodules without ulceration. Although the rCDV-TSA- and rCDV-LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV-LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs.

  10. Potential role for dog fleas in the cycle of Leishmania spp.

    Science.gov (United States)

    Ferreira, Marilia Gabriele Prado Albuquerque; Fattori, Karina Reinaldo; Souza, Fausto; Lima, Valéria Marçal Felix

    2009-10-28

    Several species of Leishmania spp. cause diseases in humans that range from self-healing cutaneous lesions to fatal visceral leishmaniosis. It has been observed that besides being transmitted by sand flies, Leishmania spp. may also be transmitted by arthropods such as ticks and fleas. To investigate the possible role of dog fleas in the transmission of Leishmania spp., Ctenocefalides felis were removed from 22 dogs which were positive according to ELISA and rK-39 tests. A C. felis sample from each of the 22 dogs was used to infect a hamster. The 22 hamsters were euthanized 4 months after infection with the fleas and the blood was subjected to ELISA to detect antibody anti-Leishmania spp., and the spleen samples were submitted to PCR for detection of Leishmania spp. DNA. PCR and ELISA were both positive in 18.1% (4/22), with PCR alone being positive in 45% (10/22) and ELISA alone in only 9% (2/22). These results suggest the participation of dog fleas in the Leishmania spp. cycle. Confirmation that C. felis indeed transmit leishmaniosis to dogs requires new strategies against leishmaniosis to be enforced by public health authorities and which focus on better ways to keep dogs free of fleas.

  11. Inoculação experimental de Equus asinus com Leishmania chagasi Cunha & Chagas, 1937 Experimental infection of Equus asinus with Leishmania chagasi Cunha & Chagas, 1937

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    Elúzio José Lima Cerqueira

    2003-12-01

    Full Text Available Quatro Equus asinus foram inoculados com promastigotas de Leishmania chagasi Cunha & Chagas, 1937 e acompanhados durante 12 meses através de: pesquisa de amastigotas em esfregaços e culturas de sangue periférico em fragmentos de tecido do lábio inferior, medula óssea, baço e fígado e de testes de ELISA e TRALd. Estes foram positivos nos 8º, 10º e 12º meses após a inoculação. O exame histopatológico pós necropsia, demonstrou discreto número de amastigotas no fígado de dois dos eqüídeos inoculados. Apesar de desafiados com elevado número de promastigotas, os animais não desenvolveram infecções patentes e não infectaram experimentalmente a vetora Lutzomya longipalpis. Os resultados induzem a acreditar que os eqüídeos são desprovidos de importância como reservatórios na cadeia de transmissão da leishmaniose visceral, embora sirvam como boa fonte de alimentação sangüínea e proliferação da vetora Lutzomyia longipalpis.Four Equus asinus were challenged with promastigotes of Leishmania chagasi Cunha & Chagas, 1937, and followed up for 12 months. They were observed by means of direct testing for promastigotes in smears and culture of peripheral blood, fragments from inferior lip, bone marrow, spleen and liver and the immunological assays ELISA and TRALd. The post-necropsy histological examination demonstrated a small number of amastigotes in the liver of two animals. ELISA and TRALd tests were positive at the 8th, 10th and 12th month after inoculation. The results suggest that the donkeys were able to overcome the experimental leishmanial infection and did not infect the vector Lutzomyia longipalpis in the laboratory. Consequently they can not be considered an important reservoir in the epidemiological chain of transmission of visceral leishmaniasis, although they represent an important blood source for the vector and its proliferation.

  12. Identification of a differentially expressed mRNA in axenic Leishmania panamensis amastigotes

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    José Arturo Gutiérrez

    2001-08-01

    Full Text Available Differential display technique was applied in order to identify transcripts which are present in axenic amastigotes but not in promastigotes of the Leishmania panamensis parasites. One of them was cloned and the sequence reveals an open reading frame of 364 amino acids (aprox. 40 kDa. The deduced protein is homologous to the serine/threonine protein kinases and specially to the mitogen activates protein kinases from eukaryotic species. Southern blot analysis suggest that this transcript, named lpmkh, is present in the genome of the parasite as a single copy gene. These results could imply that lpmkh could be involved in the differentiation process or the preservation of amastigotes in axenic conditions.

  13. First occurrence of an autochthonous canine case of Leishmania (Leishmania infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil

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    Elisa San Martin Mouriz Savani

    2011-08-01

    Full Text Available An autochthonous case of visceral leishmaniasis is reported in a dog (Canis familiaris as an apparently natural infection in a non-endemic area. DNA obtained from spleen and liver samples produced the expected fragment in a Leishmania-specific rDNA-based nested-PCR assay. The PCR product, a 490 bp fragment, was sequenced and the nucleotide sequence was identical to that of Leishmania (Leishmania infantum chagasi. These results are surprising since no autochthonous human or canine cases of visceral leishmaniasis have ever been reported in this municipality. This case suggests that natural transmission of this disease is occurring in this area.

  14. Antileishmanial and antifungal activity of plants used in traditional medicine in Brazil.

    Science.gov (United States)

    Braga, Fernanda G; Bouzada, Maria Lúcia M; Fabri, Rodrigo L; de O Matos, Magnum; Moreira, Francis O; Scio, Elita; Coimbra, Elaine S

    2007-05-04

    The antileishmanial and antifungal activity of 24 methanol extracts from 20 plants, all of them used in the Brazilian traditional medicine for the treatment of several infectious and inflammatory disorders, were evaluated against promastigotes forms of two species of Leishmania (L. amazonensis and L. chagasi) and two yeasts (Candida albicans and Cryptococcus neoformans). Among the 20 tested methanolic extracts, those of Vernonia polyanthes was the most active against L. amazonensis (IC(50) of 4 microg/ml), those of Ocimum gratissimum exhibited the best activity against L. chagasi (IC(50) of 71 microg/ml). Concerning antifungical activity, Schinus terebintifolius, O. gratissimum, Cajanus cajan, and Piper aduncum extracts were the most active against C. albicans (MIC of 1.25 mg/ml) whereas Bixa orellana, O. gratissimum and Syzygium cumini exhibited the best activity against C. neoformans (MIC of 0.078 mg/ml).

  15. 2-propen-1-amine derivatives and their synthetic intermediates: activity against pathogenic trypanosomatids.

    Science.gov (United States)

    de Souza, A O; Hemerly, F P; Gomes-Cardoso, L; Santa-Rita, R M; Leon, L L; de Castro, S L; Durán, N

    2004-12-01

    The potential activity of three new derivatives of 3-(4'-Y-[1,1'-biphenyl]-4-yl)-3-(4-X-phenyl)-N,N-dimethyl-2-propen-1-amine (2-PAMs) was assayed against Trypanosoma cruzi and Leishmania amazonensis. They showed higher activity against trypomastigotes and epimastigotes of T. cruzi than the standard drugs, crystal violet and nifurtimox. Besides these derivatives, a series of eleven 2-PAMs derivatives and the corresponding intermediates, biphenyl methanones (BPMs) were assayed against promastigotes of L. amazonensis, showing that the 2-PAMs were remarkably more active than the BPMs. The PAMs 2c, 2e and 2j were about 2-fold more active that pentamidine isothionate and between 27.2- and 46.4-fold less toxic to V79 mammalian cells. The present results encourage further studies, especially against intracellular parasites and in experimental animals.

  16. RIPK1 and PGAM5 Control Leishmania Replication through Distinct Mechanisms.

    Science.gov (United States)

    Farias Luz, Nivea; Balaji, Sakthi; Okuda, Kendi; Barreto, Aline Silva; Bertin, John; Gough, Peter J; Gazzinelli, Ricardo; Almeida, Roque P; Bozza, Marcelo T; Borges, Valeria M; Chan, Francis Ka-Ming

    2016-06-15

    Leishmaniasis is an important parasitic disease found in the tropics and subtropics. Cutaneous and visceral leishmaniasis affect an estimated 1.5 million people worldwide. Despite its human health relevance, relatively little is known about the cell death pathways that control Leishmania replication in the host. Necroptosis is a recently identified form of cell death with potent antiviral effects. Receptor interacting protein kinase 1 (RIPK1) is a critical kinase that mediates necroptosis downstream of death receptors and TLRs. Heme, a product of hemoglobin catabolism during certain intracellular pathogen infections, is also a potent inducer of macrophage necroptosis. We found that human visceral leishmaniasis patients exhibit elevated serum levels of heme. Therefore, we examined the impact of heme and necroptosis on Leishmania replication. Indeed, heme potently inhibited Leishmania replication in bone marrow-derived macrophages. Moreover, we found that inhibition of RIPK1 kinase activity also enhanced parasite replication in the absence of heme. We further found that the mitochondrial phosphatase phosphoglycerate mutase family member 5 (PGAM5), a putative downstream effector of RIPK1, was also required for inhibition of Leishmania replication. In mouse infection, both PGAM5 and RIPK1 kinase activity are required for IL-1β expression in response to Leishmania However, PGAM5, but not RIPK1 kinase activity, was directly responsible for Leishmania-induced IL-1β secretion and NO production in bone marrow-derived macrophages. Collectively, these results revealed that RIPK1 and PGAM5 function independently to exert optimal control of Leishmania replication in the host. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. A Historical Overview of the Classification, Evolution, and Dispersion of Leishmania Parasites and Sandflies.

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    Mohammad Akhoundi

    2016-03-01

    Full Text Available The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale.Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53, sandflies (more than 800 at genus or subgenus level, and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate?We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites.

  18. A Historical Overview of the Classification, Evolution, and Dispersion of Leishmania Parasites and Sandflies

    Science.gov (United States)

    Akhoundi, Mohammad; Kuhls, Katrin; Cannet, Arnaud; Votýpka, Jan; Marty, Pierre; Delaunay, Pascal; Sereno, Denis

    2016-01-01

    Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they

  19. A Historical Overview of the Classification, Evolution, and Dispersion of Leishmania Parasites and Sandflies.

    Science.gov (United States)

    Akhoundi, Mohammad; Kuhls, Katrin; Cannet, Arnaud; Votýpka, Jan; Marty, Pierre; Delaunay, Pascal; Sereno, Denis

    2016-03-01

    The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites.

  20. The epidemiology and control of leishmaniasis in Andean countries Epidemiologia e controle da leishmaniose nos países andinos

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    Clive Richard Davies

    2000-12-01

    Full Text Available This paper reviews the current knowledge of leishmaniasis epidemiology in Venezuela, Colombia, Ecuador, Peru, and Bolivia. In all 5 countries leishmaniasis is endemic in both the Andean highlands and the Amazon basin. The sandfly vectors belong to subgenera Helcocyrtomyia, Nyssomiya, Lutzomyia, and Psychodopygus, and the Verrucarum group. Most human infections are caused by Leishmania in the Viannia subgenus. Human Leishmania infections cause cutaneous lesions, with a minority of L. (Viannia infections leading to mucocutaneous leishmaniasis. Visceral leishmaniasis and diffuse cutaneous leishmaniasis are both rare. In each country a significant proportion of Leishmania transmission is in or around houses, often close to coffee or cacao plantations. Reservoir hosts for domestic transmission cycles are uncertain. The paper first addresses the burden of disease caused by leishmaniasis, focusing on both incidence rates and on the variability in symptoms. Such information should provide a rational basis for prioritizing control resources, and for selecting therapy regimes. Secondly, we describe the variation in transmission ecology, outlining those variables which might affect the prevention strategies. Finally, we look at the current control strategies and review the recent studies on control.Este trabalho revisa o conhecimento atual sobre a epidemiologia da leishmaniose na Venezuela, Colômbia, Equador, Peru e Bolívia, países nos quais a doença é endêmica, tanto nos Andes quanto na Amazônia. Os vetores flebótomos pertencem a vários subgêneros e ao grupo Verrucarum. A maioria dos casos de infecção humana é causada pelos parasitas Leishmania do subgênero Viannia. As infecções humanas por Leishmania provocam lesões cutâneas, com uma minoria de infecções por L. (Viannia levando à leishmaniose mucocutânea. Tanto a leishmaniose visceral quanto a leishmaniose cutânea difusa são raras. Em cada país, parte significativa da transmiss

  1. Molecular detection of Leishmania infection due to Leishmania major and Leishmania turanica in the vectors and reservoir host in Iran.

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    Rassi, Yavar; Oshaghi, Mohammad Ali; Azani, Sadegh Mohammadi; Abaie, Mohammad Reza; Rafizadeh, Sina; Mohebai, Mehdi; Mohtarami, Fatemeh; Zeinali, Mohammad kazem

    2011-02-01

    An epidemiological study was carried out on the vectors and reservoirs of cutaneous leishmaniasis in rural areas of Damghan district, Semnan province, central Iran, during 2008-2009. Totally, 6110 sand flies were collected using sticky papers and were subjected to molecular methods for detection of Leishmania parasite. Phlebotomus papatasi Scopoli was the common species in outdoor and indoor resting places. Polymerase chain reaction technique showed that 24 out of 218 P. papatasi (11%) and 4 out of 62 Phlebotomus caucasicus Marzinovskyi (6.5%) were positive for parasites Leishmania major Yakimoff and Schokhor. Twenty-one rodent reservoir hosts captured using Sherman traps were identified as Rhombomys opimus Lichtenstein (95%) and Meriones libycus Lichtenstein (5%). Microscopic investigation on blood smear of the animals for amastigote parasites revealed 8 (40%) rodents infected with R. opimus. L. major infection in these animals was then confirmed by polymerase chain reaction against internal transcribed spacer ribosomal DNA (rDNA) loci of the parasite followed by restriction fragment length polymorphism. Further, sequence analysis of 297 bp of ITS1-rDNA loci revealed the presence of L. major and Leishmania turanica in P. papatasi, and L. major in R. opimus. This is the first molecular report of L. major infection in both vectors (P. papatasi and P. caucasicus) and reservoir host (R. opimus) in this region. The results indicated that P. papatas was the primary vector of the disease and circulating the parasite between human and reservoirs, and P. caucasicus could be considered as a secondary vector. Further, our study showed that R. opimus is the most important host reservoir for maintenance of the parasite source in the area.

  2. immune response in human leishmania infections Respuesta inmune en infecciones humanas por Leishmania spp

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    Sara María Robledo Restrepo

    2000-03-01

    Full Text Available This review summarizes relevant information about the immune response triggered during leishmaniosis, a disease of great importance from the epidemiological point of view, since it is endemic in Colombia and other countries. We emphasize on human leishmaniosis; nevertheless, some important findings in the murine model are also mentioned. This information allows to conclude that Leishmania infection is a complex and coordinated process, which includes adhesion and entrance of the parasite into the host cells and its survival inside them. Events that mediate the infection process may influence its result in terms of elimination of the parasite or development of the disease, through induction or not of an effective specific immune response which involves host cell activation and parasite destruction. La presente revisión tiene como objetivo resumir la información más relevante acerca de la respuesta inmune que se desencadena durante la leishmaniosis, una enfermedad de gran importancia desde el punto de vista epidemiológico dado que es endémica en Colombia y otros países. Aunque la respuesta inmune en la leishmaniosis es un tema que se ha estudiado ampliamente en las infecciones por especies de Leishmania del Viejo Mundo, particularmente Leishmania major y Leishmania donovani y en el modelo murino, la presente revisión hace énfasis en la leishmaniosis humana. Algunos hallazgos importantes en el modelo murino también se mencionan. La información contenida en la revisión, en su mayoría, proviene de publicaciones derivadas de investigaciones, las cuales se seleccionaron con base en la calidad del trabajo realizado y en los aportes de sus resultados en el avance del conocimiento sobre las infecciones en humanos. La síntesis de la información seleccionada nos permite concluir que la infección por Leishmania es un proceso complejo y coordinado que incluye la adherencia y entrada del parásito a la célula hospedera y su posterior

  3. Leishmanicidal activity of polyphenolic-rich extract from husk fiber of Cocos nucifera Linn. (Palmae).

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    Mendonça-Filho, Ricardo R; Rodrigues, Igor A; Alviano, Daniela S; Santos, André L S; Soares, Rosangela M A; Alviano, Celuta S; Lopes, Angela H C S; Rosa, Maria do Socorro S

    2004-04-01

    The available therapy for leishmaniasis, which affects 2 million people per annum, still causes serious side effects. The polyphenolic-rich extract from the husk fiber of Cocos nucifera Linn. (Palmae) presents antibacterial and antiviral activities, also inhibiting lymphocyte proliferation, as shown by our group in previous works. In the present study, the in vitro leishmanicidal effects of C. nucifera on Leishmania amazonensis were evaluated. The minimal inhibitory concentration of the polyphenolic-rich extract from C. nucifera to completely abrogate parasite growth was 10 microg/ml. Pretreatment of peritoneal mouse macrophages with 10 microg/ml of C. nucifera polyphenolic-rich extract reduced approximately 44% the association index between these macrophages and L. amazonensis promastigotes, with a concomitant increase of 182% in nitric oxide production by the infected macrophage in comparison to nontreated macrophages. These results provide new perspectives on drug development against leishmaniasis, since the extract of C. nucifera at 10 microg/ml is a strikingly potent leishmanicidal substance which inhibited the growth of both promastigote and amastigote developmental stages of L. amazonensis after 60 min, presenting no in vivo allergenic reactions or in vitro cytotoxic effects in mammalian systems.

  4. Epidemiological study on leishmaniasis in an area of environmental tourism and ecotourism, State of Mato Grosso do Sul, 2006-2007.

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    Andrade, Ana Rachel Oliveira de; Nunes, Vânia Lúcia Brandão; Galati, Eunice Aparecida Bianchi; de Arruda, Carla Cardozo Pinto; Santos, Mirella Ferreira da Cunha; Rocca, Maria Elizabeth Gizi; Aquino, Ricardo Braga

    2009-01-01

    The aims of this study were to carry out a serological survey of canine leishmaniasis and identify the phlebotomine fauna in the urban area of Bonito, Mato Grosso do Sul. The serological survey was conducted on a sample of 303 dogs, by means of the indirect immunofluorescence test. Phlebotomines were captured using automated light traps. The serological survey found that 30% of the dogs were seropositive, both from the center and from all districts of the town. A total of 2,772 specimens of phlebotomines were caught and the species most found was Lutzomyia longipalpis (90.4%), which corroborated its role as the vector of for canine visceral leishmaniasis in the region. Phlebotomines of the species Bichromomyia flaviscutellata (the main vector for Leishmania (Leishmania) amazonensis) and Nyssomyia whitmani (the vector for Leishmania (Viannia) brasiliensis) were also caught. The findings indicate the need for continuous epidemiological surveillance, with attention towards diminishing the vector breeding sites and the transmission of these diseases in that region.

  5. Innate Immunity to Leishmania Infection: Within Phagocytes

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    Marcela Freitas Lopes

    2014-01-01

    Full Text Available Infection by Leishmania takes place in the context of inflammation and tissue repair. Besides tissue resident macrophages, inflammatory macrophages and neutrophils are recruited to the infection site and serve both as host cells and as effectors against infection. Recent studies suggest additional important roles for monocytes and dendritic cells. This paper addresses recent experimental findings regarding the regulation of Leishmania major infection by these major phagocyte populations. In addition, the role of IL-4 on dendritic cells and monocytes is discussed.

  6. LeishCyc: a biochemical pathways database for Leishmania major

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    Doyle Maria A

    2009-06-01

    Full Text Available Abstract Background Leishmania spp. are sandfly transmitted protozoan parasites that cause a spectrum of diseases in more than 12 million people worldwide. Much research is now focusing on how these parasites adapt to the distinct nutrient environments they encounter in the digestive tract of the sandfly vector and the phagolysosome compartment of mammalian macrophages. While data mining and annotation of the genomes of three Leishmania species has provided an initial inventory of predicted metabolic components and associated pathways, resources for integrating this information into metabolic networks and incorporating data from transcript, protein, and metabolite profiling studies is currently lacking. The development of a reliable, expertly curated, and widely available model of Leishmania metabolic networks is required to facilitate systems analysis, as well as discovery and prioritization of new drug targets for this important human pathogen. Description The LeishCyc database was initially built from the genome sequence of Leishmania major (v5.2, based on the annotation published by the Wellcome Trust Sanger Institute. LeishCyc was manually curated to remove errors, correct automated predictions, and add information from the literature. The ongoing curation is based on public sources, literature searches, and our own experimental and bioinformatics studies. In a number of instances we have improved on the original genome annotation, and, in some ambiguous cases, collected relevant information from the literature in order to help clarify gene or protein annotation in the future. All genes in LeishCyc are linked to the corresponding entry in GeneDB (Wellcome Trust Sanger Institute. Conclusion The LeishCyc database describes Leishmania major genes, gene products, metabolites, their relationships and biochemical organization into metabolic pathways. LeishCyc provides a systematic approach to organizing the evolving information about Leishmania

  7. In Vitro and In Vivo Evaluation of Essential Oil from Artemisia absinthium L. Formulated in Nanocochleates against Cutaneous Leishmaniasis

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    Beatriz Tamargo

    2017-06-01

    Full Text Available Background: Leishmaniasis is a zoonotic disease caused by protozoan parasites from Leishmania genus. Currently, there are no effective vaccines available and the available therapies are far from ideal. In particular, the development of new therapeutic strategies to reduce the infection caused by Leishmania amazonensis could be considered desirable. Different plant-derived products have demonstrated antileishmanial activity, including the essential oil (EO from Artemisia absinthium L. (EO-Aa, Asteraceae. Methods: In the present study, the EO-Aa formulated in nanocochleates (EO-Aa-NC was investigated in vitro against intracellular amastigotes of L. amazonensis and non-infected macrophages from BALB/c mice. In addition, the EO-Aa-NC was also evaluated in vivo against on experimental cutaneous leishmaniasis, which body weight, lesion progression, and parasite load were determined. Results: EO-Aa-NC displayed IC50 values of 21.5 ± 2.5 μg/mL and 27.7 ± 5.6 μg/mL against intracellular amastigotes of L. amazonensis and non-infected peritoneal macrophage, respectively. In the animal model, the EO-Aa-NC (30 mg/kg/intralesional route/every 4 days 4 times showed no deaths or weight loss greater than 10%. In parallel, the EO-Aa-NC suppressed the infection in the murine model by approximately 50%, which was statistically superior (p < 0.05 than controls and mice treated with EO-Aa. In comparison with Glucantime®, EO-Aa-NC inhibited the progression of infection as efficiently (p > 0.05 as administration of the reference drug. Conclusions: Encochleation of EO-Aa resulted in a stable, tolerable, and efficacious antileishmanial formulation, facilitating systemic delivery of EO, with increased activity compared to administration of the free EO-Aa. This new formulation shows promising potential to future studies aimed at a new therapeutic strategy to treat leishmaniasis.

  8. Leishmania mexicana Gp63 cDNA Using Gene Gun Induced Higher Immunity to L. mexicana Infection Compared to Soluble Leishmania Antigen in BALB/C

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    Rezvan, H; Rees, R; Ali, SA

    2011-01-01

    Background Leishmaniasis is a worldwide disease prevalent in tropical and sub tropical countries. Many attempts have been made and different strategies have been approached to develop a potent vaccine against Leishmania. DNA immunisation is a method, which is shown to be effective in Leishmania vaccination. Leishmania Soluble Antigen (SLA) has also recently been used Leishmania vaccination. Methods The immunity generated by SLA and L. mexicana gp63 cDNA was compared in groups of 6 mice, which were statistically analysed by student t- test with the P-value of 0.05. SLA was administered by two different methods; intramuscular injection and injection of dendritic cells (DCs) loaded with SLA. L. mexicana gp63 cDNA was administered by the gene gun. Results Immunisation of BALB/c mice with L. mexicana gp63 resulted in high levels of Th1-type immune response and cytotoxic T lymphocytes (CTL) activity, which were accompanied with protection induced by the immunisation against L. mexicana infection. In contrast, administration of SLA, produced a mixed Th1/Th2-type immune responses as well as a high level of CTL activity but did not protect mice from the infection. Conclusion The results indicate higher protection by DNA immunisation using L. mexicana gp63 cDNA compared to SLA, which is accompanied by a high level of Th1 immune response. However, the CTL activity does not necessarily correlate with the protection induced by the vaccine. Also, gene gun immunisation is a potential approach in Leishmania vaccination. These findings would be helpful in opening new windows in Leishmania vaccine research. PMID:22347315

  9. Leishmania serology in the diagnosis of cutaneous leishmaniasis

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    Mashood, A.H.; Malik, N.; Abbasi, S.

    2013-01-01

    Background: The gold standard to diagnose cutaneous leishmaniasis is histopathology, but there has always been a need of a rapid, reliable, cheap and convenient laboratory investigation. Serological tests fulfill the above criteria. Objective: The objective of the study was to determine the sensitivity and specificity of enzyme linked immunosorbent assay (ELISA) in detection of leishmania antibodies, in comparison with the histopathology. Place and duration of study: The study was conducted in Military Hospital Rawalpindi from 1st November 2010 to 30th June 2011. Patients and methods: The study population included the patients who were clinically diagnosed with cutaneous leishmaniasis. All of them were biopsied and serum was sent for leishmania serology. Results: A total of 47 patients were included. They were all adult males. The histopathology was positive in 31/47 patients (65.95%), while the leishmania serology was positive in 36/47 cases (76.59%). The sensitiuites was 74.19%, specificity was 18.75%, positive predictive value has 63.88%, negative predicative value was 27% and accuracy was 55%. Conclusion: In the light of sensitivity analysis, it may be concluded that leishmania serology has moderate sensitivity and low specificity; hence it is not a reliable test for cutaneous leishmaniasis. (author)

  10. Identification of geographically distributed sub-populations of Leishmania (Leishmania major by microsatellite analysis

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    Schwenkenbecher Jan

    2008-06-01

    Full Text Available Abstract Background Leishmania (Leishmania major, one of the agents causing cutaneous leishmaniasis (CL in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of L. (L. major isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of Leishmania. Results Multilocus Microsatellite Typing (MLMT based on 10 different microsatellite markers was applied to 106 strains of L. (L. major from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA; the Middle East (ME; and Africa (AF. This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration. Conclusion The model- and distance-based analyses of the microsatellite data exposed three main populations of L. (L. major, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.

  11. Genome-wide mapping reveals single-origin chromosome replication in Leishmania, a eukaryotic microbe.

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    Marques, Catarina A; Dickens, Nicholas J; Paape, Daniel; Campbell, Samantha J; McCulloch, Richard

    2015-10-19

    DNA replication initiates on defined genome sites, termed origins. Origin usage appears to follow common rules in the eukaryotic organisms examined to date: all chromosomes are replicated from multiple origins, which display variations in firing efficiency and are selected from a larger pool of potential origins. To ask if these features of DNA replication are true of all eukaryotes, we describe genome-wide origin mapping in the parasite Leishmania. Origin mapping in Leishmania suggests a striking divergence in origin usage relative to characterized eukaryotes, since each chromosome appears to be replicated from a single origin. By comparing two species of Leishmania, we find evidence that such origin singularity is maintained in the face of chromosome fusion or fission events during evolution. Mapping Leishmania origins suggests that all origins fire with equal efficiency, and that the genomic sites occupied by origins differ from related non-origins sites. Finally, we provide evidence that origin location in Leishmania displays striking conservation with Trypanosoma brucei, despite the latter parasite replicating its chromosomes from multiple, variable strength origins. The demonstration of chromosome replication for a single origin in Leishmania, a microbial eukaryote, has implications for the evolution of origin multiplicity and associated controls, and may explain the pervasive aneuploidy that characterizes Leishmania chromosome architecture.

  12. Unraveling the genetic diversity and phylogeny of Leishmania RNA virus 1 strains of infected Leishmania isolates circulating in French Guiana.

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    Tirera, Sourakhata; Ginouves, Marine; Donato, Damien; Caballero, Ignacio S; Bouchier, Christiane; Lavergne, Anne; Bourreau, Eliane; Mosnier, Emilie; Vantilcke, Vincent; Couppié, Pierre; Prevot, Ghislaine; Lacoste, Vincent

    2017-07-01

    Leishmania RNA virus type 1 (LRV1) is an endosymbiont of some Leishmania (Vianna) species in South America. Presence of LRV1 in parasites exacerbates disease severity in animal models and humans, related to a disproportioned innate immune response, and is correlated with drug treatment failures in humans. Although the virus was identified decades ago, its genomic diversity has been overlooked until now. We subjected LRV1 strains from 19 L. (V.) guyanensis and one L. (V.) braziliensis isolates obtained from cutaneous leishmaniasis samples identified throughout French Guiana with next-generation sequencing and de novo sequence assembly. We generated and analyzed 24 unique LRV1 sequences over their full-length coding regions. Multiple alignment of these new sequences revealed variability (0.5%-23.5%) across the entire sequence except for highly conserved motifs within the 5' untranslated region. Phylogenetic analyses showed that viral genomes of L. (V.) guyanensis grouped into five distinct clusters. They further showed a species-dependent clustering between viral genomes of L. (V.) guyanensis and L. (V.) braziliensis, confirming a long-term co-evolutionary history. Noteworthy, we identified cases of multiple LRV1 infections in three of the 20 Leishmania isolates. Here, we present the first-ever estimate of LRV1 genomic diversity that exists in Leishmania (V.) guyanensis parasites. Genetic characterization and phylogenetic analyses of these viruses has shed light on their evolutionary relationships. To our knowledge, this study is also the first to report cases of multiple LRV1 infections in some parasites. Finally, this work has made it possible to develop molecular tools for adequate identification and genotyping of LRV1 strains for diagnostic purposes. Given the suspected worsening role of LRV1 infection in the pathogenesis of human leishmaniasis, these data have a major impact from a clinical viewpoint and for the management of Leishmania-infected patients.

  13. NKT cell activation by Leishmania mexicana LPG: Description of a novel pathway.

    Science.gov (United States)

    Zamora-Chimal, Jaime; Fernández-Figueroa, Edith A; Ruiz-Remigio, Adriana; Wilkins-Rodríguez, Arturo A; Delgado-Domínguez, José; Salaiza-Suazo, Norma; Gutiérrez-Kobeh, Laila; Becker, Ingeborg

    2017-02-01

    NKT cells have been associated with protection against Leishmania donovani, yet their role in infections with Leishmania mexicana has not been addressed, nor has the activation pathway been defined after stimulation with Leishmania mexicana lipophosphoglycan (LPG). We analyzed the activation of NKT cells and their cytokine production in response to Leishmania mexicana LPG. Additionally we compared NKT-cell numbers and cytokine profile in lymph nodes of skin lesions induced by Leishmania mexicana in BALB/c and C57BL/6 mice. We show that LPG activates NKT cells primarily through the indirect pathway, initiating with TLR2 stimulation of dendritic cells (DC), thereby enhancing TLR2, MHC II, and CD86 expressions and IL-12p70 production. This leads to IFN-γ production by NKT cells. C57BL/6 mice showed enhanced DC activation, which correlated with augmented IFN-γ production by NKT cells. Additionally, infected C57BL/6 mice showed elevated percentages of NKT cells with higher IFN-γ and IL-4 production in lymph nodes. We conclude that the response of NKT cells towards Leishmania mexicana LPG initiates with the indirect activation, after binding of LPG to TLR2 in DC. This indirect activation pathway enables NKT cells to produce IFN-γ during the innate phase of Leishmania infection, the magnitude of which differs between mouse strains. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  14. Dihydrotestosterone enhances growth and infectivity of Leishmania Mexicana.

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    Sánchez-García, L; Wilkins-Rodriguez, A; Salaiza-Suazo, N; Morales-Montor, J; Becker, I

    2018-03-01

    A strong sex-associated susceptibility towards Leishmania has been reported in males, yet little is known on the effect of hormones in Leishmania physiopathogenicity. Due to the enhanced susceptibility of males to Leishmania mexicana infections, we were interested in analysing the effect exerted by the main androgen produced in males (DHT) on L. mexicana promastigotes. Thus, the aim of this study was to assess the regulation exerted by dihydrotestosterone (DHT) on L. mexicana replication, infectivity, survival and development of tissue lesions. Experiments included growth curves of L. mexicana promastigotes incubated with different doses of DHT, their infection rate, intracellular survival and lesion development in BALB/c mice. Our data show that DHT significantly enhances parasite replication, infection rate and survival in bone marrow-derived macrophages (BMMФ). Promastigotes in the presence of DHT produced significantly larger lesions in BALB/c earlobes. These results suggest that DHT probably plays a critical role during L. mexicana infections, and the higher susceptibility of males possibly relates to benefits gained by the parasite from host-derived hormones. Our data shed new light on the physiopathology of Leishmania infections and are the first attempt to understand the direct interaction between Leishmania and androgens, particularly DHT. Understanding this trans-regulation process employed by parasites to exploit host molecules sheds new light on L. mexicana physiopathogenesis and opens a possible field for studies on drug development. © 2017 John Wiley & Sons Ltd.

  15. Triphenylmethane derivatives have high in vitro and in vivo activity against the main causative agents of cutaneous leishmaniasis.

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    Renata Celi Carvalho de Souza Pietra

    Full Text Available The current standard of care for cutaneous leishmaniasis (CL is organic antimonial compounds, but the administration of these compounds is complicated by a low therapeutic - toxic index, as well as parenteral administration. Thus, there is an urgent need for the development of new and inexpensive therapies for the treatment of CL. In this study, we evaluate the activity of the triphenylmethane (TPM class of compounds against three species of Leishmania which are pathogenic in humans. The TPM have a history of safe use in humans, dating back to the use of the original member of this class, gentian violet (GV, from the early 20(th century. Initially, the in vitro efficacy against Leishmania (Viannia braziliensis, L. (Leishmania amazonensis and L. (L. major of 9 newly synthesized TPM, in addition to GV, was tested. Inhibitory concentrations (IC IC(50 of 0.025 to 0.84 µM had been found in promastigotes in vitro assays. The four most effective compounds were then tested in amastigote intracellular assays, resulting in IC(50 of 0.10 to 1.59 µM. A high degree of selectivity of antiparasitic activity over toxicity to mammalian cells was observed. Afterwards, GV and TPM 6 were tested in a topical formulation in mice infected with L. (L. amazonensis leading to elimination of parasite burdens at the site of lesion/infection. These results demonstrated that TPM present significant anti-leishmanial activities and provide a rationale for human clinical trials of GV and other TPM. TPM are inexpensive and safe, thus using them for treatment of CL may have a major impact on public health.

  16. Evaluation of the antiplasmodial and leishmanicidal potential of Myrciaria dubia (Myrtaceae) extract.

    Science.gov (United States)

    Correia, Vanessa Carolina de Sena; Lima, Nathália Oliveira; Oliveira, Flávio Augusto de Souza; Santos, Ana Paula de Azevedo Dos; Teles, Carolina Bioni Garcia; Oliveira, Waldesse Piragé de; Pimenta, And Raphael Sanzio

    2016-01-01

    Malaria and leishmaniasis are prevalent in tropical regions, which have environmental characteristics that are highly favorable to protozoa and vectors of these diseases; the transmission of these infections in sub-tropical regions, although recognized, represents only a small fraction of cases. Plants are constantly being used in the search for and acquisition of new drugs, and many compounds derived from them have been used to combat various diseases. In this study, we evaluated the action of the dichloromethanolic extract of Myrciaria dubia leaves against the protozoa Plasmodium falciparum, Leishmania amazonensis, Leishmania braziliensis, and Leishmania chagasi through bioassays. The extract from M. dubia was tested for its anti-P. falciparum activity in an anti-histidine-rich protein II immunosorbent assay. The antileishmanial assays were performed using the resazurin method, while cytotoxicity against human hepatoma (HepG2) strain was determined using the colorimetric MTT [3-(4, 5-dimethyl-2- thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide] method. The M. dubia extract presented a half-maximal inhibitory concentration equal to 2.35 (1.05)μg/mL for P. falciparum, 190.73 (6.41) μg/mL for L. amazonensis, and greater than equal to 200µg/mL for L. chagasi and L. braziliensis strains. The cytotoxic concentration for 50% of the cells was above 500μg/mL for HepG2, indicating no toxicity and greater selectivity against parasites. The results obtained indicate the presence of antiplasmodial and leishmanicidal bioactive compounds in the dichloromethanolic extracts of M. dubia leaves, and point towards future studies to elucidate the mechanism of action for each physiological effect.

  17. Evaluation of the antiplasmodial and leishmanicidal potential of Myrciaria dubia (Myrtaceae extract

    Directory of Open Access Journals (Sweden)

    Vanessa Carolina de Sena Correia

    Full Text Available Abstract INTRODUCTION: Malaria and leishmaniasis are prevalent in tropical regions, which have environmental characteristics that are highly favorable to protozoa and vectors of these diseases; the transmission of these infections in sub-tropical regions, although recognized, represents only a small fraction of cases. Plants are constantly being used in the search for and acquisition of new drugs, and many compounds derived from them have been used to combat various diseases. In this study, we evaluated the action of the dichloromethanolic extract of Myrciaria dubia leaves against the protozoa Plasmodium falciparum, Leishmania amazonensis, Leishmania braziliensis, and Leishmania chagasi through bioassays. METHODS The extract from M. dubia was tested for its anti-P. falciparum activity in an anti-histidine-rich protein II immunosorbent assay. The antileishmanial assays were performed using the resazurin method, while cytotoxicity against human hepatoma (HepG2 strain was determined using the colorimetric MTT [3-(4, 5-dimethyl-2- thiazolyl-2, 5-diphenyl-2H tetrazolium bromide] method. RESULTS The M. dubia extract presented a half-maximal inhibitory concentration equal to 2.35 (1.05μg/mL for P. falciparum, 190.73 (6.41 μg/mL for L. amazonensis, and greater than equal to 200µg/mL for L. chagasi and L. braziliensis strains. The cytotoxic concentration for 50% of the cells was above 500μg/mL for HepG2, indicating no toxicity and greater selectivity against parasites. CONCLUSIONS The results obtained indicate the presence of antiplasmodial and leishmanicidal bioactive compounds in the dichloromethanolic extracts of M. dubia leaves, and point towards future studies to elucidate the mechanism of action for each physiological effect.

  18. A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania

    Science.gov (United States)

    Lyda, Todd A.; Joshi, Manju B.; Andersen, John F.; Kelada, Andrew Y.; Owings, Joshua P.; Bates, Paul A.; Dwyer, Dennis M.

    2015-01-01

    Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts. PMID:25763714

  19. T-cell responses associated with resistance to Leishmania infection in individuals from endemic areas for Leishmania (Viannia braziliensis

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    Rita C Bittar

    2007-08-01

    Full Text Available Subclinical or asymptomatic infection is documented in individuals living in endemic areas for leishmaniasis suggesting that the development of an appropriate immune response can control parasite replication and maintain tissue integrity. A low morbidity indicates that intrinsic factors could favor resistance to Leishmania infection. Herein, leishmanial T-cell responses induced in subjects with low susceptibility to leishmaniasis as asymptomatic subjects were compared to those observed in cured cutaneous leishmaniasis (CCL patients, who controlled the disease after antimonial therapy. All of them have shown maintenance of specific long-term immune responses characterized by expansion of higher proportions of CD4+ as compared to CD8+ Leishmania reactive T-lymphocytes. Asymptomatic subjects had lower indexes of in vitro Leishmania induced lymphoproliferative responses and interferon-gamma (IFN-gamma production in comparison to CCL patients. On the other hand, interleukin (IL-10 production was much higher in asymptomatics than in CCL, while no differences in IL-5 levels were found. In conclusion, long lived T-cell responses achieved by asymptomatic individuals differed from those who had developed symptomatic leishmaniasis in terms of intensity of lymphocyte activation (proliferation or IFN-gamma and regulatory mechanisms (IL-10. The absence of the disease in asymptomatics could be explained by their intrinsic ability to create a balance between immunoregulatory (IL-10 and effector cytokines (IFN-gamma, leading to parasite destruction without producing skin tissue damage. The establishment of profiles of cell-mediated immune responses associated with resistance against Leishmania infection is likely to make new inroads into understanding the long-lived immune protection against the disease.

  20. Functional Characterization of Monomeric GTPase Rab1 in the Secretory Pathway of Leishmania*

    Science.gov (United States)

    Bahl, Surbhi; Parashar, Smriti; Malhotra, Himanshu; Raje, Manoj; Mukhopadhyay, Amitabha

    2015-01-01

    Leishmania secretes a large number of its effectors to the extracellular milieu. However, regulation of the secretory pathway in Leishmania is not well characterized. Here, we report the cloning, expression, and characterization of the Rab1 homologue from Leishmania. We have found that LdRab1 localizes in Golgi in Leishmania. To understand the role of LdRab1 in the secretory pathway of Leishmania, we have generated transgenic parasites overexpressing GFP-LdRab1:WT, GFP-LdRab1:Q67L (a GTPase-deficient dominant positive mutant of Rab1), and GFP-LdRab1:S22N (a GDP-locked dominant negative mutant of Rab1). Surprisingly, our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N does not disrupt the trafficking and localization of hemoglobin receptor in Leishmania. To determine whether the Rab1-dependent secretory pathway is conserved in parasites, we have analyzed the role of LdRab1 in the secretion of secretory acid phosphatase and Ldgp63 in Leishmania. Our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N significantly inhibits the secretion of secretory acid phosphatase by Leishmania. We have also found that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N retains RFP-Ldgp63 in Golgi and blocks the secretion of Ldgp63, whereas the trafficking of RFP-Ldgp63 in GFP-LdRab1:WT-expressing cells is unaltered in comparison with control cells. Taken together, our results have shown that the Rab1-regulated secretory pathway is well conserved, and hemoglobin receptor trafficking follows an Rab1-independent secretory pathway in Leishmania. PMID:26499792

  1. Functional Characterization of Monomeric GTPase Rab1 in the Secretory Pathway of Leishmania.

    Science.gov (United States)

    Bahl, Surbhi; Parashar, Smriti; Malhotra, Himanshu; Raje, Manoj; Mukhopadhyay, Amitabha

    2015-12-11

    Leishmania secretes a large number of its effectors to the extracellular milieu. However, regulation of the secretory pathway in Leishmania is not well characterized. Here, we report the cloning, expression, and characterization of the Rab1 homologue from Leishmania. We have found that LdRab1 localizes in Golgi in Leishmania. To understand the role of LdRab1 in the secretory pathway of Leishmania, we have generated transgenic parasites overexpressing GFP-LdRab1:WT, GFP-LdRab1:Q67L (a GTPase-deficient dominant positive mutant of Rab1), and GFP-LdRab1:S22N (a GDP-locked dominant negative mutant of Rab1). Surprisingly, our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N does not disrupt the trafficking and localization of hemoglobin receptor in Leishmania. To determine whether the Rab1-dependent secretory pathway is conserved in parasites, we have analyzed the role of LdRab1 in the secretion of secretory acid phosphatase and Ldgp63 in Leishmania. Our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N significantly inhibits the secretion of secretory acid phosphatase by Leishmania. We have also found that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N retains RFP-Ldgp63 in Golgi and blocks the secretion of Ldgp63, whereas the trafficking of RFP-Ldgp63 in GFP-LdRab1:WT-expressing cells is unaltered in comparison with control cells. Taken together, our results have shown that the Rab1-regulated secretory pathway is well conserved, and hemoglobin receptor trafficking follows an Rab1-independent secretory pathway in Leishmania. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Preparation of live attenuated leishmania parasites by using laser technology

    Science.gov (United States)

    Hussain, Nabiha; Alkhouri, Hassan; Haddad, Shaden

    2018-05-01

    Leishmaniasis is a parasitic disease of humans, affecting the skin, mucosal and/or internal organs, caused by flagellate protozoa Leishmania of the Trypanosomatidae family. Leishmania would be one for which a vaccine could be developed with relative ease. Many studies mount an effective response that resolves the infection and confers solid immunity to reinfection and suggesting that infection may be a prerequisite for immunological memory. Genetically altered live attenuated parasites with controlled infectivity could achieve such immunological memory. Recent concepts include use of genetically modified live-attenuated Leishmania parasites, and proteomics approach for the search of a cross-protective leishmanial vaccine that would ideally protect against both cutaneous and visceral forms of the disease. No licensed vaccine is available till date against any form of leishmaniasis. The present study evaluated role of laser technology in development of a safe live Leishmania vaccine, a vaccine is a biological preparation that improves immunity to a particular disease, and is often made from weakened or killed forms of LPs. The parasite culture was expanded in RPMI 1640 medium with 10% fetal calf serum (FCS) and grown until stationary phase for experiments. 80 samples of leishmania promastigotes (Culture media of LPs) were exposed to Nd:YAG laser (wavelength 1064 nm, single spot or double) with different outputs powers (7w, 100 Hz, 99.03w/cm2, 0.99 J/cm2 and 8 w, 100 Hz, 113.18w/cm2 1.13J/cm2)) for suitable exposer times. The effect of semiconductor laser (wavelength 810 nm, 7w, 2000 Hz, 99.03w/cm2, 0.05 J/cm2) or (7 w, 500 Hz, 99.03 w/cm2, 0.2J/cm2) single spot or double with long exposure times. The viability of Leishmania parasites was measured using XTT method; viable parasites were decreased with long exposure times. XTT test referred both these wavelengths were effective in killing percentage of Leishmania promastigotes, the remaining were devoid flagellum that

  3. Avaliaçao do efeito do extrato de casca de cajueiro-branco (Anacardium occidentale L. Sobre A infecção por Leishmania (Viannia brasiliensis

    Directory of Open Access Journals (Sweden)

    Flávio França

    1993-09-01

    Full Text Available Este trabalho apresenta uma avaliação do efeito terapêutico do extrato hidroalcólico da casca de Anacardium occidentale L sobre a Leishmania (Viannia brasiliensis. No modelo in vitro o extrato vegetal mostrou-se ativo contra promastigotas do parasita, contrastando com o modelo in vivo, onde não se observou qualquer atividade curativa.

  4. Monocyte Chemotactic Protein 1 in Plasma from Soluble Leishmania Antigen-Stimulated Whole Blood as a Potential Biomarker of the Cellular Immune Response to Leishmania infantum

    Directory of Open Access Journals (Sweden)

    Ana V. Ibarra-Meneses

    2017-09-01

    Full Text Available New biomarkers are needed to identify asymptomatic Leishmania infection as well as immunity following vaccination or treatment. With the aim of finding a robust biomarker to assess an effective cellular immune response, monocyte chemotactic protein 1 (MCP-1 was examined in plasma from soluble Leishmania antigen (SLA-stimulated whole blood collected from subjects living in a Leishmania infantum-endemic area. MCP-1, expressed 110 times more strongly than IL-2, identified 87.5% of asymptomatic subjects and verified some asymptomatic subjects close to the cutoff. MCP-1 was also significantly elevated in all patients cured of visceral leishmaniasis (VL, unlike IL-2, indicating the specific memory response generated against Leishmania. These results show MCP-1 to be a robust candidate biomarker of immunity that could be used as a marker of cure and to both select and follow the population in vaccine phase I–III human clinical trials with developed rapid, easy-to-use field tools.

  5. DSFL database: A hub of target proteins of Leishmania sp. to combat leishmaniasis

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    Ameer Khusro

    2017-07-01

    Full Text Available Leishmaniasis is a vector-borne chronic infectious tropical dermal disease caused by the protozoa parasite of the genus Leishmania that causes high mortality globally. Among three different clinical forms of leishmaniasis, visceral leishmaniasis (VL or kala-azar is a systemic public health disease with high morbidity and mortality in developing countries, caused by Leishmania donovani, Leishmania infantum or Leishmania chagasi. Unfortunately, there is no vaccine available till date for the treatment of leishmaniasis. On the other hand, the therapeutics approved to treat this fatal disease is expensive, toxic, and associated with serious side effects. Furthermore, the emergence of drug-resistant Leishmania parasites in most endemic countries due to the incessant utilization of existing drugs is a major concern at present. Drug Search for Leishmaniasis (DSFL is a unique database that involves 50 crystallized target proteins of varied Leishmania sp. in order to develop new drugs in future by interacting several antiparasitic compounds or molecules with specific protein through computational tools. The structure of target protein from different Leishmania sp. is available in this database. In this review, we spotlighted not only the current global status of leishmaniasis in brief but also detailed information about target proteins of various Leishmania sp. available in DSFL. DSFL has created a new expectation for mankind in order to combat leishmaniasis by targeting parasitic proteins and commence a new era to get rid of drug resistance parasites. The database will substantiate to be a worthwhile project for further development of new, non-toxic, and cost-effective antileishmanial drugs as targeted therapies using in vitro/in vivo assays.

  6. Detección de Leishmania spp. en base al gen que codifica la proteína HSP20

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    Ana M Montalvo

    Full Text Available Objetivos. Explorar una nueva diana para el diagnóstico molecular de Leishmania. Materiales y métodos. Se evaluó la utilidad del gen que codifica la proteína de choque térmico de 20kDa (hsp20 para la detección de Leishmania por medio de la reacción en cadena de la polimerasa (PCR.Se normalizó la PCR y se determinaron los parámetros analíticos, así como la validez y seguridad diagnóstica y la concordancia con la PCR-18S. Se evaluó la PCR-hsp20 con ADN obtenido de un grupo de muestras clínicas de distinta procedencia. Resultados. Los parámetros analíticos resultaron adecuados. La sensibilidad obtenida fue de 86% y la especificidad del 100%, la concordancia con el método de referencia resultó buena (κ = 0,731, lo que apoya su posible uso para el diagnóstico. La posibilidad de identificación posterior de la especie mediante secuenciación del producto amplificado le confiere una ventaja adicional. Conclusiones. Se demuestra la utilidad de este gen como una nueva diana para la detección del género Leishmania. Debido a su potencial, se recomienda mejorar la sensibilidad del procedimiento y realizar su evaluación en diversas regiones endémicas.

  7. Molecular detection of Leishmania infantum and Leishmania tropica in rodent species from endemic cutaneous leishmaniasis areas in Morocco.

    Science.gov (United States)

    Echchakery, Mohamed; Chicharro, Carmen; Boussaa, Samia; Nieto, Javier; Carrillo, Eugenia; Sheila, Ortega; Moreno, Javier; Boumezzough, Ali

    2017-10-02

    Leishmaniasis remains a major public health problem in African nations, including Morocco, where little is known about the vertebrate reservoirs involved in the causal parasites' transmission cycles. The present study investigates the role of rodent species as potential reservoirs of Leishmania spp. in central Morocco, where both L. tropica and L. infantum have been reported. Rodents were caught from 22 sites in central Morocco, by using Sherman metal traps, and identified morphologically. For each specimen, genomic DNA was extracted from different tissues using the Speed Tools DNA extraction Kit. Then, samples were PCR-analyzed, targeting the SSU rRNA gene to detect Leishmania spp. DNA, followed by amplification of the internal transcribed spacer 1 (ITS1) and its sequencing to identify the species. A total of 197 rodents belonging to ten species were captured and identified: Rattus rattus (40.61%), Mus musculus (25.38%), Apodemus sylvaticus (8.63%), Mus spretus (7.11%), Meriones shawi (5.58%), Rattus norvegicus (4.57%), Meriones libycus (3.05%), Mastomys erythroleucus (2.03%), Gerbillus campestris (2.03%) and Lemniscomys barbarus (1.01%). Molecular analysis revealed the presence of Leishmania species in 18 specimens: six R. rattus (out of 80 captured; 7.5%), 11 M. musculus (out of 50 captured; 22%), and one R. norvegicus (out of 9 captured; 11.11%). To the best of our knowledge, L. infantum and L. tropica were identified in rodent species for the first time in Morocco. These findings suggest that rodent species may be involved in L. infantum and L. tropica transmission cycles in this country but that further studies are needed to confirm their role as reservoirs of Leishmania species in Morocco.

  8. Serological and molecular survey of Leishmania parasites in apparently healthy dogs in the West Bank, Palestine

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    Hamarsheh Omar

    2012-08-01

    Full Text Available Abstract Background Canine visceral leishmaniasis (CVL is caused by Leishmania infantum in all Mediterranean countries. The Leishmania parasite is transmitted by the bite of a corresponding sand fly vector and primarily maintained in nature by wild and domestic reservoirs, including dogs, foxes and jackals. Infected dogs are the primary reservoir host in endemic regions and are the most significant risk disposing humans to infection. The present study aimed at assessing the prevalence of infection with Leishmania and identification of Leishmania infantum in domestic dogs in the West Bank, Palestine. Methods The infection rate among domestic dogs collected from seven districts in the Palestinian West Bank was investigated by examination of parasites in culture from the buffy coat using serological and molecular methods; based on ELISA, internal transcribed spacer 1 (ITS1 and cysteine protease (CPB PCR. Results Out of 215 dogs examined for Leishmania, 36 (16.7% were positive in at least one method. Twenty three animals (11.5% were positive for Leishmania DNA, whereas, ELISA and culture revealed 16 (7.5%, and 4 (1.5% respectively. CPB-PCR on one of three culture-positive isolates revealed Leishmania infantum as the causative agent for Leishmania infection in dogs. Conclusions Our study showed that canine leishmania infection is prevalent with varying degrees in all the seven studied districts in Palestine despite the absence of human VL cases in 4 of these districts. The causative agent was confirmed to be Leishmania infantum.

  9. Identification of Tunisian Leishmania spp. by PCR amplification of cysteine proteinase B (cpb) genes and phylogenetic analysis.

    Science.gov (United States)

    Chaouch, Melek; Fathallah-Mili, Akila; Driss, Mehdi; Lahmadi, Ramzi; Ayari, Chiraz; Guizani, Ikram; Ben Said, Moncef; Benabderrazak, Souha

    2013-03-01

    Discrimination of the Old World Leishmania parasites is important for diagnosis and epidemiological studies of leishmaniasis. We have developed PCR assays that allow the discrimination between Leishmania major, Leishmania tropica and Leishmania infantum Tunisian species. The identification was performed by a simple PCR targeting cysteine protease B (cpb) gene copies. These PCR can be a routine molecular biology tools for discrimination of Leishmania spp. from different geographical origins and different clinical forms. Our assays can be an informative source for cpb gene studying concerning drug, diagnostics and vaccine research. The PCR products of the cpb gene and the N-acetylglucosamine-1-phosphate transferase (nagt) Leishmania gene were sequenced and aligned. Phylogenetic trees of Leishmania based cpb and nagt sequences are close in topology and present the classic distribution of Leishmania in the Old World. The phylogenetic analysis has enabled the characterization and identification of different strains, using both multicopy (cpb) and single copy (nagt) genes. Indeed, the cpb phylogenetic analysis allowed us to identify the Tunisian Leishmania killicki species, and a group which gathers the least evolved isolates of the Leishmania donovani complex, that was originated from East Africa. This clustering confirms the African origin for the visceralizing species of the L. donovani complex. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. LR1: a candidate RNA virus of Leishmania.

    OpenAIRE

    Tarr, P I; Aline, R F; Smiley, B L; Scholler, J; Keithly, J; Stuart, K

    1988-01-01

    Although viruses are important biological agents and useful molecular tools, little is known about the viruses of parasites. We report here the discovery of a candidate for an RNA virus in a kinetoplastid parasite. This potential virus, which we term LR1, is present in the promastigote form of the human pathogen Leishmania braziliensis guyanensis CUMC1-1A but not in 11 other stocks of Leishmania that were examined nor in Trypanosoma brucei. The candidate viral RNA has a size of approximately ...

  11. Characterization of Leishmania Soluble Exo-Antigen

    National Research Council Canada - National Science Library

    Cui, Liwang

    2003-01-01

    .... Vaccine development is the ultimate solution for this problem. Our previous research indicates that Leishmania parasites secrete, excrete, or shed antigens into the medium during in vitro culture...

  12. Leishmania (L. mexicana infected bats in Mexico: novel potential reservoirs.

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    Miriam Berzunza-Cruz

    2015-01-01

    Full Text Available Leishmania (Leishmania mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L. mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L. mexicana DNA. We found that 41 bats (9.77%, belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus, and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L. mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L. mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology.

  13. Leishmania (L.) mexicana Infected Bats in Mexico: Novel Potential Reservoirs

    Science.gov (United States)

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R.; Hidalgo-Mihart, Mircea; Marina, Carlos F.; Rebollar-Téllez, Eduardo A.; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N.; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

  14. Characterization of a subunit of the outer dynein arm docking complex necessary for correct flagellar assembly in Leishmania donovani.

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    Simone Harder

    Full Text Available BACKGROUND: In order to proceed through their life cycle, Leishmania parasites switch between sandflies and mammals. The flagellated promastigote cells transmitted by the insect vector are phagocytized by macrophages within the mammalian host and convert into the amastigote stage, which possesses a rudimentary flagellum only. During an earlier proteomic study of the stage differentiation of the parasite we identified a component of the outer dynein arm docking complex, a structure of the flagellar axoneme. The 70 kDa subunit of the outer dynein arm docking complex consists of three subunits altogether and is essential for the assembly of the outer dynein arm onto the doublet microtubule of the flagella. According to the nomenclature of the well-studied Chlamydomonas reinhardtii complex we named the Leishmania protein LdDC2. METHODOLOGY/PRINCIPAL FINDINGS: This study features a characterization of the protein over the life cycle of the parasite. It is synthesized exclusively in the promastigote stage and localizes to the flagellum. Gene replacement mutants of lddc2 show reduced growth rates and diminished flagellar length. Additionally, the normally spindle-shaped promastigote parasites reveal a more spherical cell shape giving them an amastigote-like appearance. The mutants lose their motility and wiggle in place. Ultrastructural analyses reveal that the outer dynein arm is missing. Furthermore, expression of the amastigote-specific A2 gene family was detected in the deletion mutants in the absence of a stage conversion stimulus. In vitro infectivity is slightly increased in the mutant cell line compared to wild-type Leishmania donovani parasites. CONCLUSIONS/SIGNIFICANCE: Our results indicate that the correct assembly of the flagellum has a great influence on the investigated characteristics of Leishmania parasites. The lack of a single flagellar protein causes an aberrant morphology, impaired growth and altered infectiousness of the parasite.

  15. Anti-Leishmania and cytotoxic activities of perillaldehyde epoxide synthetic positional isomers.

    Science.gov (United States)

    Keesen, Tatjana Souza Lima; da Silva, Larisse Virgolino; da Câmara Rocha, Juliana; Andrade, Luciana Nalone; Lima, Tamires Cardoso; de Sousa, Damião Pergentino

    2018-03-13

    Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC 50  = 3.8 μg.mL -1 ) was 16-fold more potent than its isomer EPER-1 (IC 50  = 64.6 μg.mL -1 ). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC 50  > 400 μg.mL -1 ) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies.

  16. Leishmania exosomes and other virulence factors: Impact on innate immune response and macrophage functions.

    Science.gov (United States)

    Atayde, Vanessa Diniz; Hassani, Kasra; da Silva Lira Filho, Alonso; Borges, Andrezza Raposo; Adhikari, Anupam; Martel, Caroline; Olivier, Martin

    2016-11-01

    Leishmania parasites are the causative agents of the leishmaniases, a collection of vector-borne diseases that range from simple cutaneous to fatal visceral forms. Employing potent immune modulation mechanisms, Leishmania is able to render the host macrophage inactive and persist inside its phagolysosome. In the last few years, the role of exosomes in Leishmania-host interactions has been increasingly investigated. For instance, it was reported that Leishmania exosome release is augmented following temperature shift, a condition mimicking parasite's entry into its mammalian host. Leishmania exosomes were found to strongly affect macrophage cell signaling and functions, similarly to whole parasites. Importantly, these vesicles were shown to be pro-inflammatory, capable to recruit neutrophils at their inoculation site exacerbating the pathology. In this review, we provide the most recent insights on the role of exosomes and other virulence factors, especially the surface protease GP63, in Leishmania-host interactions, deepening our knowledge on leishmaniasis and paving the way for the development of new therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification

    Science.gov (United States)

    Vikeved, Elisabet; Backlund, Anders; Alsmark, Cecilia

    2016-01-01

    Background The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT). Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania. Methodology/Principal Findings To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species. Conclusions/Significance LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets. PMID:26730948

  18. The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification.

    Science.gov (United States)

    Vikeved, Elisabet; Backlund, Anders; Alsmark, Cecilia

    2016-01-01

    The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT). Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania. To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species. LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

  19. The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification.

    Directory of Open Access Journals (Sweden)

    Elisabet Vikeved

    2016-01-01

    Full Text Available The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT. Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania.To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species.LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

  20. Peptone-yeast autolysate-fetal bovine serum 10, a simple, inexpensive liquid medium for cultivation of Leishmania spp.

    OpenAIRE

    Palomino, J C

    1982-01-01

    A simple liquid medium for the cultivation of Leishmania parasites is described. Leishmania brasiliensis and Leishmania peruviana cultured in this medium reached cell densities greater than 10(7) promastigotes per ml within 7 days. This medium compares very favorably with the more complex media used to cultivate Leishmania spp. and other hemoflagellates.

  1. Further support for a palaearctic origin of Leishmania

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    Sara F Kerr

    2000-08-01

    Full Text Available The fossil record and systematics of murid rodents, reservoirs of zoonotic cutaneous leishmaniasis in the Palaearctic, Oriental, African, Nearctic and Neotropical, strongly support a Palaearctic origin of Leishmania. The fossil record and systematics of phlebotomine sand flies reinforce this idea. Interpretations of molecular data that place the origin of Leishmania in the Neotropical are inconsistent with the natural histories of reservoirs and vectors. The evolutionary pattern of New World rats (Sigmodontinae indicates that they may be the most important reservoirs of zoonotic cutaneous leishmaniasis throughout their range.

  2. Leishmaniose cutânea na Amazônia: isolamento de Leishmania (Viannia lainsoni do roedor Agouti paca (Rodentia: Dasyproctidae, no estado do Pará, Brasil Cutaneous leishmaniasis in the Amazon Region: isolation of Leishmania (Viannia lainsoni from the rodent Agouti paca (Rodentia: Dasyproctidae in Pará State, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando T. Silveira

    1991-02-01

    Full Text Available Fez-se o registro, pela primeira vez, do isolamento de Leishmania (V. lainsoni de um mamífero silvestre, o roedor Agouti paca (Rodentia: Dasyproctidae, no Estado do Pará, Brasil. As amostras do parasita foram isoladas da pele, aparentemente íntegra, de 3 espécimes desse roedor, capturados no município de Tucuruí (ilha de Tocantins, em área que seria inundada pela formação do lago da hidrelétrica construída naquele município. Nenhum isolamento foi obtido de vísceras de qualquer dos animais. A identificação das amostras de L. (V. lainsoni baseou-se na morfologia de amastigotas e promastigotas, no comportamento da infecção em "hamsters", na análise bioquímica de isoenzimas e, ainda, através de testes com anticorpos monoclonais. A natureza inaparente da infecção nos animais faz supor que o mamífero em questão possa representar um hospedeiro definitivo do parasita na região Amazônica.The isolation of Leishmania (V. lainsoni is recorded for the first time from a wild animal, the rodent Agouti paca (Rodentia: Dasyproctidae, from Pará State, north Brazil. Isolates of the parasite were made from apparently normal skin of 3 specimens of this rodent captured on the Island of Tocantins, in the municipality of Tucuruí, an area subsequently flooded in the formation of the lake associated with the Tucuruí hydroeletric dam. No isolations were made from the viscera. Identification of the parasite was in each case based on morphology of the amastigotes and promastigotes, behavior of the organism in hamsters, isoenzymes profiles and the use of monoclonal antibodies. The inapparent nature of the infection leads us to suggest that the "paca", Agouti paca, represents a primitive host of L. (V. lainsoni in the Amazon Region.

  3. Large-Scale Investigation of Leishmania Interaction Networks with Host Extracellular Matrix by Surface Plasmon Resonance Imaging

    Science.gov (United States)

    Fatoux-Ardore, Marie; Peysselon, Franck; Weiss, Anthony; Bastien, Patrick; Pratlong, Francine

    2014-01-01

    We have set up an assay to study the interactions of live pathogens with their hosts by using protein and glycosaminoglycan arrays probed by surface plasmon resonance imaging. We have used this assay to characterize the interactions of Leishmania promastigotes with ∼70 mammalian host biomolecules (extracellular proteins, glycosaminoglycans, growth factors, cell surface receptors). We have identified, in total, 27 new partners (23 proteins, 4 glycosaminoglycans) of procyclic promastigotes of six Leishmania species and 18 partners (15 proteins, 3 glycosaminoglycans) of three species of stationary-phase promastigotes for all the strains tested. The diversity of the interaction repertoires of Leishmania parasites reflects their dynamic and complex interplay with their mammalian hosts, which depends mostly on the species and strains of Leishmania. Stationary-phase Leishmania parasites target extracellular matrix proteins and glycosaminoglycans, which are highly connected in the extracellular interaction network. Heparin and heparan sulfate bind to most Leishmania strains tested, and 6-O-sulfate groups play a crucial role in these interactions. Numerous Leishmania strains bind to tropoelastin, and some strains are even able to degrade it. Several strains interact with collagen VI, which is expressed by macrophages. Most Leishmania promastigotes interact with several regulators of angiogenesis, including antiangiogenic factors (endostatin, anastellin) and proangiogenic factors (ECM-1, VEGF, and TEM8 [also known as anthrax toxin receptor 1]), which are regulated by hypoxia. Since hypoxia modulates the infection of macrophages by the parasites, these interactions might influence the infection of host cells by Leishmania. PMID:24478075

  4. Identification of a secreted casein kinase 1 in Leishmania donovani: effect of protein over expression on parasite growth and virulence.

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    Mary Dan-Goor

    Full Text Available Casein kinase 1 (CK1 plays an important role in eukaryotic signaling pathways, and their substrates include key regulatory proteins involved in cell differentiation, proliferation and chromosome segregation. The Leishmania genome encodes six potential CK1 isoforms, of which five have orthologs in other trypanosomatidae. Leishmania donovani CK1 isoform 4 (Ldck1.4, orthologous to LmjF27.1780 is unique to Leishmania and contains a putative secretion signal peptide. The full-length gene and three shorter constructs were cloned and expressed in E. coli as His-tag proteins. Only the full-length 62.3 kDa protein showed protein kinase activity indicating that the N-terminal and C-terminal domains are essential for protein activity. LdCK1.4-FLAG was stably over expressed in L. donovani, and shown by immunofluorescence to be localized primarily in the cytosol. Western blotting using anti-FLAG and anti-CK1.4 antibodies showed that this CK1 isoform is expressed and secreted by promastigotes. Over expression of LdCK1.4 had a significant effect on promastigote growth in culture with these parasites growing to higher cell densities than the control parasites (wild-type or Ld:luciferase, P<0.001. Analysis by flow cytometry showed a higher percentage, ∼4-5-fold, of virulent metacyclic promastigotes on day 3 among the LdCK1.4 parasites. Finally, parasites over expressing LdCK1.4 gave significantly higher infections of mouse peritoneal macrophages compared to wild-type parasites, 28.6% versus 6.3%, respectively (p = 0.0005. These results suggest that LdCK1.4 plays an important role in parasite survival and virulence. Further studies are needed to validate CK1.4 as a therapeutic target in Leishmania.

  5. Actividad in vitro de la mezcla de alcaloides de Ervatamia coronaria (Jacq Staff. Apocynaceae sobre amastigotes de Leishmania braziliensis

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    Amanda Moreno Rodríguez

    Full Text Available A leishmaniose é considerada uma importante causa de morbidade e mortalidade a nível mundial, principalmente nos países tropicais. As formas cutânea e mucocutânea são causadas, entre outras espécies, por Leishmania braziliensis. Na procura de compostos leishmanicidas de origem natural, foi estudada a atividade da mistura de alcalóides de Ervatamia coronaria (Apocynaceae contra amastigotas de L. braziliensis em 6 concentrações diferentes (1, 10, 20, 25, 50 e 100 µg/mL. Foram tratados macrófagos de ratos da linha J774, infectados com promastigotas de L. braziliensis, com a mistura de alcalóides 1 hora após-infecção e diariamente por 3 dias sem mudança de meio. As experiências de citotoxicidade foram efetuadas sobre os macrófagos com azul tripam. Todos os cultivos foram feitos de forma triplicada e os grupos de controle não foram submetidos à mistura de alcalóides. Foi obtido que o composto adicionado exerce atividade doses/dependente sobre a parasita. No entanto, as concentrações mais altas (50 e 100 µg/mL, adicionado durante 3 dias, mostraram os maiores índices de infecção, provavelmente devido a diminuição no número de macrófagos, sobre os quais não foi observado efeito tóxico do tratamento durante 24 horas DL50/24h = 233,52 µg/mL. Os resultados dessa pesquisa revelaram uma nova atividade farmacológica de alcalóides da espécie Ervatamia coronaria sobre a forma amastigota de Leishmania braziliensis, com IC50 = 2,6 e 12,4 µg/mL sem mostrar toxicidade sobre a célula hospedeira.

  6. Therapeutic switching: from antidermatophytic essential oils to new leishmanicidal products

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    Emeline Houël

    2015-02-01

    Full Text Available This study examined whether the antidermatophytic activity of essential oils (EOs can be used as an indicator for the discovery of active natural products against Leishmania amazonensis. The aerial parts of seven plants were hydrodistilled. Using broth microdilution techniques, the obtained EOs were tested against three strains of dermatophytes (Trichophyton mentagrophytes, Microsporum gypseum and Microsporum canis. To compare the EOs antifungal and antiparasitic effects, the EOs activities against axenic amastigotes of L. amazonensis were concurrently evaluated. For the most promising EOs, their antileishmanial activities against parasites infecting peritoneal macrophages of BALB/c mice were measured. The most interesting antifungal candidates were the EOs from Cymbopogon citratus, Otacanthus azureus and Protium heptaphyllum, whereas O. azureus, Piper hispidum and P. heptaphyllum EOs exhibited the lowest 50% inhibitory concentration (IC50 values against axenic amastigotes, thus revealing a certain correspondence between both activities. The P. hispidum EO was identified as the most promising product in the results from the infected macrophages model (IC50: 4.7 µg/mL, safety index: 8. The most abundant compounds found in this EO were sesquiterpenes, notably curzerene and furanodiene. Eventually, the evaluation of the antidermatophytic activity of EOs appears to be an efficient method for identifying new potential drugs for the treatment of L. amazonensis.

  7. Species-Specific Antimonial Sensitivity in Leishmania Is Driven by Post-Transcriptional Regulation of AQP1

    Science.gov (United States)

    Mandal, Goutam; Mandal, Srotoswati; Sharma, Mansi; Charret, Karen Santos; Papadopoulou, Barbara; Bhattacharjee, Hiranmoy; Mukhopadhyay, Rita

    2015-01-01

    Leishmania is a digenetic protozoan parasite causing leishmaniasis in humans. The different clinical forms of leishmaniasis are caused by more than twenty species of Leishmania that are transmitted by nearly thirty species of phlebotomine sand flies. Pentavalent antimonials (such as Pentostam or Glucantime) are the first line drugs for treating leishmaniasis. Recent studies suggest that pentavalent antimony (Sb(V)) acts as a pro-drug, which is converted to the more active trivalent form (Sb(III)). However, sensitivity to trivalent antimony varies among different Leishmania species. In general, Leishmania species causing cutaneous leishmaniasis (CL) are more sensitive to Sb(III) than the species responsible for visceral leishmaniasis (VL). Leishmania aquaglyceroporin (AQP1) facilitates the adventitious passage of antimonite down a concentration gradient. In this study, we show that Leishmania species causing CL accumulate more antimonite, and therefore exhibit higher sensitivity to antimonials, than the species responsible for VL. This species-specific differential sensitivity to antimonite is directly proportional to the expression levels of AQP1 mRNA. We show that the stability of AQP1 mRNA in different Leishmania species is regulated by their respective 3’-untranslated regions. The differential regulation of AQP1 mRNA explains the distinct antimonial sensitivity of each species. PMID:25714343

  8. Differential Activation of Human Keratinocytes by Leishmania Species Causing Localized or Disseminated Disease.

    Science.gov (United States)

    Scorza, Breanna M; Wacker, Mark A; Messingham, Kelly; Kim, Peter; Klingelhutz, Aloysius; Fairley, Janet; Wilson, Mary E

    2017-10-01

    All Leishmania species parasites are introduced into mammalian skin through a sand fly bite, but different species cause distinct clinical outcomes. Mouse studies suggest that early responses are critical determinants of subsequent adaptive immunity in leishmaniasis, yet few studies address the role of keratinocytes, the most abundant cell in the epidermis. We hypothesized that Leishmania infection causes keratinocytes to produce immunomodulatory factors that influence the outcome of infection. Incubation of primary or immortalized human keratinocytes with Leishmania infantum or Leishmania major, which cause visceral or cutaneous leishmaniasis, respectively, elicited dramatically different responses. Keratinocytes incubated with L. infantum significantly increased expression of proinflammatory genes for IL-6, IL-8, tumor necrosis factor, and IL-1B, whereas keratinocytes exposed to several L. major isolates did not. Furthermore, keratinocyte-monocyte co-incubation studies across a 4 µM semipermeable membrane suggested that L. infantum-exposed keratinocytes release soluble factors that enhance monocyte control of intracellular L. infantum replication (P Leishmania species that may affect the course of disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil.

    Science.gov (United States)

    Carreira, João Carlos Araujo; da Silva, Alba Valéria Machado; de Pita Pereira, Daniela; Brazil, Reginaldo Peçanha

    2012-06-07

    The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot hybridization using a L. infantum

  10. Oral Efficacy of Apigenin against Cutaneous Leishmaniasis: Involvement of Reactive Oxygen Species and Autophagy as a Mechanism of Action.

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    Fernanda Fonseca-Silva

    2016-02-01

    Full Text Available The treatment for leishmaniasis is currently based on pentavalent antimonials and amphotericin B; however, these drugs result in numerous adverse side effects. The lack of affordable therapy has necessitated the urgent development of new drugs that are efficacious, safe, and more accessible to patients. Natural products are a major source for the discovery of new and selective molecules for neglected diseases. In this paper, we evaluated the effect of apigenin on Leishmania amazonensis in vitro and in vivo and described the mechanism of action against intracellular amastigotes of L. amazonensis.Apigenin reduced the infection index in a dose-dependent manner, with IC50 values of 4.3 μM and a selectivity index of 18.2. Apigenin induced ROS production in the L. amazonensis-infected macrophage, and the effects were reversed by NAC and GSH. Additionally, apigenin induced an increase in the number of macrophages autophagosomes after the infection, surrounding the parasitophorous vacuole, suggestive of the involvement of host autophagy probably due to ROS generation induced by apigenin. Furthermore, apigenin treatment was also effective in vivo, demonstrating oral bioavailability and reduced parasitic loads without altering serological toxicity markers.In conclusion, our study suggests that apigenin exhibits leishmanicidal effects against L. amazonensis-infected macrophages. ROS production, as part of the mechanism of action, could occur through the increase in host autophagy and thereby promoting parasite death. Furthermore, our data suggest that apigenin is effective in the treatment of L. amazonensis-infected BALB/c mice by oral administration, without altering serological toxicity markers. The selective in vitro activity of apigenin, together with excellent theoretical predictions of oral availability, clear decreases in parasite load and lesion size, and no observed compromises to the overall health of the infected mice encourage us to supports

  11. Progress towards a Leishmania vaccine.

    Science.gov (United States)

    Tabbara, Khaled S

    2006-07-01

    Leishmaniasis is a vector-born protozoan disease. Approximately 12 million individuals are affected worldwide with an estimated annual incidence of 1.5-2 million. Two clinical manifestations are recognized, cutaneous, and visceral, both of which are common in the Middle East. In both forms, infection is chronic, with potential deformities, persistence following cure, and lifelong risk of reactivation. Attempts to develop an effective human Leishmania vaccine have not yet succeeded. Leishmanization, a crude form of live vaccination historically originated in this part of the world. Experimental vaccination has been extensively studied in model animals in the past 2 decades. In this review, major human killed vaccine trials are surveyed, and modern trends in Leishmania vaccine development, including subunit vaccines, naked DNA vaccines, and transmission blocking vaccines are explored. Recent findings of a link between persistence of live parasites, and maintenance of long-term immunity suggest live vaccination with attenuated strains, as a future vaccination strategy.

  12. Development of a dipstick assay for detection of Leishmania-specific canine antibodies

    NARCIS (Netherlands)

    Schallig, Henk D. F. H.; Cardoso, Luís; Hommers, Marieke; Kroon, Nel; Belling, Guus; Rodrigues, Manuela; Semião-Santos, Saul J.; Vetter, Hans

    2004-01-01

    A dipstick assay, based on Leishmania infantum antigen, for the rapid detection of Leishmania-specific antibodies in canine serum samples was developed and evaluated. After determination of optimal dipstick test conditions, test performance was compared with two existing serological tests, i.e., the

  13. An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

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    Márcia Cristina Aquino Teixeira

    2011-03-01

    Full Text Available Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

  14. The flagellar protein FLAG1/SMP1 is a candidate for Leishmania-sand fly interaction.

    Science.gov (United States)

    Di-Blasi, Tatiana; Lobo, Amanda R; Nascimento, Luanda M; Córdova-Rojas, Jose L; Pestana, Karen; Marín-Villa, Marcel; Tempone, Antonio J; Telleria, Erich L; Ramalho-Ortigão, Marcelo; McMahon-Pratt, Diane; Traub-Csekö, Yara M

    2015-03-01

    Leishmaniasis is a serious problem that affects mostly poor countries. Various species of Leishmania are the agents of the disease, which take different clinical manifestations. The parasite is transmitted by sandflies, predominantly from the Phlebotomus genus in the Old World and Lutzomyia in the New World. During development in the gut, Leishmania must survive various challenges, which include avoiding being expelled with blood remnants after digestion. It is believed that attachment to the gut epithelium is a necessary step for vector infection, and molecules from parasites and sand flies have been implicated in this attachment. In previous work, monoclonal antibodies were produced against Leishmania. Among these an antibody was obtained against Leishmania braziliensis flagella, which blocked the attachment of Leishmania panamensis flagella to Phlebotomus papatasi guts. The protein recognized by this antibody was identified and named FLAG1, and the complete FLAG1 gene sequence was obtained. This protein was later independently identified as a small, myristoylated protein and called SMP1, so from now on it will be denominated FLAG1/SMP1. The FLAG1/SMP1 gene is expressed in all developmental stages of the parasite, but has higher expression in promastigotes. The anti-FLAG1/SMP1 antibody recognized the flagellum of all Leishmania species tested and generated the expected band by western blots. This antibody was used in attachment and infection blocking experiments. Using the New World vector Lutzomyia longipalpis and Leishmania infantum chagasi, no inhibition of attachment ex vivo or infection in vivo was seen. On the other hand, when the Old World vectors P. papatasi and Leishmania major were used, a significant decrease of both attachment and infection were seen in the presence of the antibody. We propose that FLAG1/SMP1 is involved in the attachment/infection of Leishmania in the strict vector P. papatasi and not the permissive vector L. longipalpis.

  15. Severity of tegumentary leishmaniasis is not exclusively associated with Leishmania RNA virus 1 infection in Brazil

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    Luiza de Oliveira Ramos Pereira

    2013-08-01

    Full Text Available Leishmania RNA virus (LRV has been shown to be a symbiotic component of Leishmania parasites in South America. Nested retro-transcription polymerase chain reaction was employed to investigate LRV1 presence in leishmaniasis lesions from Brazil. In endemic areas of Rio de Janeiro (RJ, no LRV1 infection was observed even with mucosal involvement. LRV1 was only detected in Leishmania (V. guyanensis cutaneous lesions from the northern region, which were obtained from patients presenting with disease reactivation after clinical cure of their primary lesions. Our results indicated that the severity of leishmaniasis in some areas of RJ, where Leishmania (V. brazi-liensis is the primary etiological agent, was not associated with Leishmania LRV1 infection.

  16. Evaluation of four molecular methods to detect Leishmania infection in dogs.

    Science.gov (United States)

    Albuquerque, Andreia; Campino, Lenea; Cardoso, Luís; Cortes, Sofia

    2017-03-13

    Canine leishmaniasis, a zoonotic disease caused by Leishmania infantum vectored by phlebotomine sand flies, is considered a relevant veterinary and public health problem in various countries, namely in the Mediterranean basin and Brazil, where dogs are considered the main reservoir hosts. Not only diseased dogs but also those subclinically infected play a relevant role in the transmission of L. infantum to vectors; therefore, early diagnosis is essential, under both a clinical and an epidemiological perspective. Molecular tools can be a more accurate and sensitive approach for diagnosis, with a wide range of protocols currently in use. The aim of the present report was to compare four PCR based protocols for the diagnosis of canine Leishmania infection in a cohort of dogs from the Douro region, Portugal. A total of 229 bone marrow samples were collected from dogs living in the Douro region, an endemic region for leishmaniasis. Four PCR protocols were evaluated for Leishmania DNA detection in canine samples, three single (ITS1-PCR, MC-PCR and Uni21/Lmj4-PCR) and one nested (nested SSU rRNA-PCR). Two of the protocols were based on nuclear targets and the other two on kinetoplastid targets. The higher overall percentage of infected dogs was detected with the nested SSU rRNA-PCR (37.6%), which also was able to detect Leishmania DNA in a higher number of samples from apparently healthy dogs (25.3%). The ITS1-PCR presented the lowest level of Leishmania detection. Nested SSU rRNA-PCR is an appropriate method to detect Leishmania infection in dogs. Accurate and early diagnosis in clinically suspect as well as apparently healthy dogs is essential, in order to treat and protect animals and public health and contribute to the control and awareness of the disease.

  17. Identificación de una nueva proteína en Leishmania (Viannia peruviana

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    Maxy De los Santos

    1998-01-01

    Full Text Available El análisis de la secuencia nucleotídica y aminoacídica de un clon de la biblioteca de expresión en fago λgt11 de Leishmania (Viannia peruviana, estableció identidad parcial con los genes de las proteínas acídicas ribosomales P2 de Leishmania (Leishmania infantum. Este hallazgo unido a ciertos dominios geonómicos conservados, sugeridos de la comparación de 14 secuencias de otras proteínas P1 eucarióticas, confirman que la secuencia del inserto de clon codifica la proteína acídica ribosomal P1 de L. (V. peruviana denominada LpP1. Este es el primer reporte sobre este tipo de proteína en el género Leishmania.

  18. Mitochondrial associated ubiquitin fold modifier-1 mediated protein conjugation in Leishmania donovani.

    Directory of Open Access Journals (Sweden)

    Sreenivas Gannavaram

    2011-01-01

    Full Text Available In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1 and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2 specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.

  19. Detection of Leishmania spp in silvatic mammals and isolation of Leishmania (Viannia braziliensis from Rattus rattus in an endemic area for leishmaniasis in Minas Gerais State, Brazil.

    Directory of Open Access Journals (Sweden)

    Agnes Antônia Sampaio Pereira

    Full Text Available Knowledge of potential reservoirs of Leishmania spp. in an anthropic environment is important so that surveillance and control measures can be implemented. The aim of this study was to investigate the infection by Leishmania in small mammals in an area located in Minas Gerais, Brazil, that undergoes changes in its natural environment and presents autochthonous human cases of cutaneous leishmaniasis (CL and visceral leishmaniasis (VL. For the capture of the animals, Sherman and Tomahawk traps were used and distributed in the peridomicile of houses with reports of autochthonous cases of CL or VL. Six catches were carried out on two consecutive nights with intervals of two months during one year and samples of spleen, liver, tail skin, ear skin and bone marrow of the animals were obtained. Parasitological and molecular methods were used to detect the infection. Identification of the Leishmania species was performed by PCR RFLPhsp70. Twenty five animals of four species were captured: ten Rattus rattus, nine Didelphis albiventris, five Cerradomys subflavus and one Marmosops incanus. In the PCR-hsp70, five animals were positive (20%. The Leishmania species identified in PCR-RFLPhsp70 were: Leishmania braziliensis in D. albiventris (2, C. subflavus (1 and R. rattus (1 and Leishmania infantum in R. rattus (1. The highest positivity rate for L. braziliensis was obtained in the liver samples. The spleen was the only tissue positive for L. infantum. It was isolated in culture medium L. braziliensis from two samples (liver and spleen of R. rattus. This is the first record of isolation of L. braziliensis from R. rattus in the southeastern region of Brazil. These results are relevant to the knowledge of the epidemiology of leishmaniasis in the region, mainly in the investigation of the presence of hosts and possible reservoirs of the parasite.

  20. Notas e descrições em Hesperophanini, Eburiini, Piezocerini e Trachyderini (Coleoptera, Cerambycidae, Cerambycinae do Brasil e da Bolívia

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    Ubirajara R. Martins

    2010-01-01

    Full Text Available Novos táxons descritos - Hesperophanini: Paraliostola nigramacula sp. nov., do Brasil (Rondônia; Eburiini: Simplexeburia gen. nov., e sua espécie-tipo, S. divisa sp. nov. do Brasil (Amazonas; Piezocerini: Gorybia amazonensis sp. nov. and G. sulcata sp. nov., ambas do Brasil (Amazonas; Trachyderini: Galissus rubiventris sp. nov., da Bolívia (Santa Cruz. Notas e novos registros são apresentados para Liostola nitida Zajciw, 1962 e Ochrus chapadense Napp & Martins, 1982 (Hesperophanini; Uncieburia rogersi (Bates, 1870 e Quiacaua taguaiba Martins, 1970 (Eburiini.Notes and descriptions on Hesperophanini, Eburiini, Piezocerini and Trachyderini (Coleoptera, Cerambycidae, Cerambycinae from Brazil and Bolivia. New taxa described - Hesperophanini: Paraliostola nigramacula sp. nov. from Brazil (Rondônia; Eburiini: Simplexeburia gen. nov., and its type species, S. divisa sp. nov. from Brazil (Amazonas; Piezocerini: Gorybia amazonensis sp. nov. and G. sulcata sp. nov. both from Brazil (Amazonas; Trachyderini: Galissus rubiventris sp. nov. from Bolivia (Santa Cruz de la Sierra. Notes and records are presented for Liostola nitida Zajciw, 1962 and Ochrus chapadense Napp & Martins, 1982 (Hesperophanini; Uncieburia rogersi (Bates, 1870 and Quiacaua taguaiba Martins, 1997 (Eburiini.

  1. Presence of amastigotes in the central nervous system of hamsters infected with Leishmania sp. Presença de amastigotas em sistema nervoso central de hamster infectado com Leishmania sp.

    Directory of Open Access Journals (Sweden)

    Elisangela de Oliveira

    2011-06-01

    Full Text Available Visceral leishmaniasis (VL is a severe chronic disease caused by Leishmania (Leishmania infantum chagasi. Better knowledge on the effects caused by this disease can help develop adequate clinical management and treatment. Parasitological and immunohistochemical studies were performed golden hamsters Mesocricetus auratus infected with bone marrow from individuals with VL in the State of Mato Grosso do Sul, central-west Brazil. The effects of parasitism in the spleen, liver, kidneys, lungs, heart and brain of the animals were examined. Eighteen hamsters were inoculated intraperitoneally, and six healthy animals were used as negative controls. The animals were kept in the animal house and checked for clinical signs. Specimens of each organ were examined for the presence of amastigotes. Immunohistochemical technique was performed in all brain specimens and organs negative on the direct examination of parasites. Direct examination of amastigotes was positive in the spleen and liver of all infected animals; 33.3% showed the parasite in the kidneys and lungs, and 16.7% in the heart. Parasitic forms were seen in 83.3% (15/18 of the brain examined. Immunohistochemistry confirmed the results of the direct examination, except in two specimens of lung tissue and in the brain specimens. Other studies are needed to further clarify the effect of the parasite in the central nervous system.A leishmaniose visceral (LV é uma doença crônica grave, causada pelo parasito Leishmania (Leishmania infantum chagasi. Esclarecer as alterações provocadas pela doença é fundamental para que se adotem condutas clínicas e de tratamento adequadas. Com o objetivo de analisar a infecção experimental em hamsters da linhagem golden, Mesocricetus auratus, infectados com tecido de medula óssea de pacientes com LV no Estado de Mato Grosso do Sul, foram realizados estudos parasitológicos e de imunomarcação. Foi verificada a distribuição do parasitismo no baço, f

  2. Detection of Leishmania donovani and L. tropica in ethiopian wild rodents

    Czech Academy of Sciences Publication Activity Database

    Kassahun, A.; Sádlová, J.; Dvořák, V.; Košťálová, T.; Rohoušová, I.; Frynta, D.; Aghová, Tatiana; Yasur-Landau, D.; Lemma, W.; Hailu, A.; Baneth, G.; Warburg, A.; Volf, P.; Votýpka, J.

    2015-01-01

    Roč. 145, May 2015 (2015), s. 39-44 ISSN 0001-706X R&D Projects: GA ČR GAP506/10/0983 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Leishmania donovani * Leishmania tropica * Phlebotomine sand fly * Rodents * kDNA * ITS1 Subject RIV: EG - Zoology Impact factor: 2.380, year: 2015

  3. Impact of Leishmania metalloprotease GP63 on macrophage signaling

    Science.gov (United States)

    Isnard, Amandine; Shio, Marina T.; Olivier, Martin

    2012-01-01

    The intramacrophage protozoan parasites of Leishmania genus have developed sophisticated ways to subvert the innate immune response permitting their infection and propagation within the macrophages of the mammalian host. Several Leishmania virulence factors have been identified and found to be of importance for the development of leishmaniasis. However, recent findings are now further reinforcing the critical role played by the zinc-metalloprotease GP63 as a virulence factor that greatly influence host cell signaling mechanisms and related functions. GP63 has been found to be involved not only in the cleavage and degradation of various kinases and transcription factors, but also to be the major molecule modulating host negative regulatory mechanisms involving for instance protein tyrosine phosphatases (PTPs). Those latter being well recognized for their pivotal role in the regulation of a great number of signaling pathways. In this review article, we are providing a complete overview about the role of Leishmania GP63 in the mechanisms underlying the subversion of macrophage signaling and functions. PMID:22919663

  4. Rattus norvegicus (Rodentia: Muridae Infected by Leishmania (Leishmania infantum (syn. Le. chagasi in Brazil

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    Fabiana de Oliveira Lara-Silva

    2014-01-01

    Full Text Available In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL was also captured at high proportion (12.8%. Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares.

  5. Exosome Secretion by the Parasitic Protozoan Leishmania within the Sand Fly Midgut

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    Vanessa Diniz Atayde

    2015-11-01

    Full Text Available Despite several studies describing the secretion of exosomes by Leishmania in vitro, observation of their formation and release in vivo has remained a major challenge. Herein, we show that Leishmania constitutively secretes exosomes within the lumen of the sand fly midgut through a mechanism homologous to the mammalian pathway. Through egestion experiments, we demonstrate that Leishmania exosomes are part of the sand fly inoculum and are co-egested with the parasite during the insect’s bite, possibly influencing the host infectious process. Indeed, co-inoculation of mice footpads with L. major plus midgut-isolated or in-vitro-isolated L. major exosomes resulted in a significant increase in footpad swelling. Notably, co-injections produced exacerbated lesions through overinduction of inflammatory cytokines, in particular IL-17a. Our data indicate that Leishmania exosomes are an integral part of the parasite’s infectious life cycle, and we propose to add these vesicles to the repertoire of virulence factors associated with vector-transmitted infections.

  6. Methodology optimizing SAGE library tag-to-gene mapping: application to Leishmania

    Directory of Open Access Journals (Sweden)

    Smandi Sondos

    2012-01-01

    Full Text Available Abstract Background Leishmaniasis are widespread parasitic-diseases with an urgent need for more active and less toxic drugs and for effective vaccines. Understanding the biology of the parasite especially in the context of host parasite interaction is a crucial step towards such improvements in therapy and control. Several experimental approaches including SAGE (Serial analysis of gene expression have been developed in order to investigate the parasite transcriptome organisation and plasticity. Usual SAGE tag-to-gene mapping techniques are inadequate because almost all tags are normally located in the 3'-UTR outside the CDS, whereas most information available for Leishmania transcripts is restricted to the CDS predictions. The aim of this work is to optimize a SAGE libraries tag-to-gene mapping technique and to show how this development improves the understanding of Leishmania transcriptome. Findings The in silico method implemented herein was based on mapping the tags to Leishmania genome using BLAST then mapping the tags to their gene using a data-driven probability distribution. This optimized tag-to-gene mappings improved the knowledge of Leishmania genome structure and transcription. It allowed analyzing the expression of a maximal number of Leishmania genes, the delimitation of the 3' UTR of 478 genes and the identification of biological processes that are differentially modulated during the promastigote to amastigote differentiation. Conclusion The developed method optimizes the assignment of SAGE tags in trypanosomatidae genomes as well as in any genome having polycistronic transcription and small intergenic regions.

  7. Evolutionary comparison of prenylation pathway in kinetoplastid Leishmania and its sister Leptomonas.

    Science.gov (United States)

    Chauhan, Indira Singh; Kaur, Jaspreet; Krishna, Shagun; Ghosh, Arpita; Singh, Prashant; Siddiqi, Mohammad Imran; Singh, Neeloo

    2015-11-21

    Leptomonas is monogenetic kinetoplastid parasite of insects and is primitive in comparison to Leishmania. Comparative studies of these two kinetoplastid may share light on the evolutionary transition to dixenous parasitism in Leishmania. In order to adapt and survive within two hosts, Leishmania species must have acquired virulence factors in addition to mechanisms that mediate susceptibility/resistance to infection in the pathology associated with disease. Rab proteins are key mediators of vesicle transport and contribute greatly to the evolution of complexity of membrane transport system. In this study we used our whole genome sequence data of these two divergent kinetoplastids to analyze the orthologues/paralogues of Rab proteins. During change of lifestyle from monogenetic (Leptomonas) to digenetic (Leishmania), we found that the prenyl machinery remained unchanged. Geranylgeranyl transferase-I (GGTase-I) was absent in both Leishmania and its sister Leptomonas. Farnesyltransferase (FTase) and geranylgeranyl transferase-II (GGTase-II) were identified for protein prenylation. We predict that activity of the missing alpha-subunit (α-subunit) of GGTase-II in Leptomonas was probably contributed by the α-subunit of FTase, while beta-subunit (β-subunit) of GGTase-II was conserved and indicated functional conservation in the evolution of these two kinetoplastids. Therefore the β-subunit emerges as an excellent target for compounds inhibiting parasite activity in clinical cases of co-infections. We also confirmed that during the evolution to digenetic life style in Leishmania, the parasite acquired capabilities to evade drug action and maintain parasite virulence in the host with the incorporation of short-chain dehydrogenase/reductase (SDR/MDR) superfamily in Rab genes. Our study based on whole genome sequences is the first to build comparative evolutionary analysis and identification of prenylation proteins in Leishmania and its sister Leptomonas. The information

  8. Affinity labeling of the folate-methotrexate transporter from Leishmania donovani

    International Nuclear Information System (INIS)

    Beck, J.T.; Ullman, B.

    1989-01-01

    An affinity labeling technique has been developed to identify the folate-methotrexate transporter of Leishmania donovani promastigotes using activated derivatives of the ligands. These activated derivatives were synthesized by incubating folate and methotrexate with a 10-fold excess of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) for 10 min at ambient temperature in dimethyl sulfoxide. When intact wild-type (DI700) Leishmania donovani or preparations of their membranes were incubated with a 0.4 μM concentration of either activated [ 3 H]folate or activated [ 3 H]methotrexate, the radiolabeled ligands were covalently incorporated into a polypeptide with a molecular weight of approximately 46,000, as demonstrated by SDS-polyacrylamide gel electrophoresis. No affinity labeling of a 46,000-dalton protein was observed when equimolar concentrations of activated radiolabeled ligands were incubated with intact cells or membranes prepared from a methotrexate-resistant mutant clone of Leishmania donovani, MTXA5, that is genetically defective in folate-methotrexate transport capability. Time course studies indicated that maximal labeling of the 46,000-dalton protein occurred within 5-10 min of incubation of intact cells with activated ligand. These studies provide biochemical evidence that the folate-methotrexate transporter of Leishmania donovani can be identified in crude extracts by an affinity labeling technique and serve as a prerequisite to further analysis of the transport protein by providing a vehicle for subsequent purification of this membrane carrier. Moreover, these investigations suggest that the affinity labeling technique using EDC-activated ligands may be exploitable to analyze other cell surface binding proteins in Leishmania donovani, as well as in other organisms

  9. Synthesis, X-ray crystal structure and theoretical calculations of antileishmanial neolignan analogues

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Josenaide P. do; Santos, Lourivaldo S.; Carmo, Maria Carolina L. do; Brasil, Davi S.B.; Alves, Claudio N., E-mail: nahum@ufpa.b [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Ciencias Exatas e Naturais; Santos, Regina Helena A.; Tozzo, Erica; Ferreira, Janaina G. [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Inst. de Quimica

    2010-07-01

    The synthesis and X-ray crystal diffraction structure of two analogues of neolignans, 2-(4-chlorophenyl)-1-phenylethanone (20) and 2-[(4-chlorophenyl)thio]-1-(3,4-dimethoxyphenyl) propan-1-one (12) is described. The compound 12 presents activity against intracellular Leishmania donovani and Leishmania amazonensis amastigotes that cause cutaneous and visceral leishmaniasis. In addition, the density functional theory (DFT) with the B3LYP hybrid functional was employed to calculate a set of molecular descriptors for nineteen synthetic analogues of neolignans with antileishmanial activities. Afterwards, the stepwise discriminant analysis was performed to investigate possible relationship between the molecular descriptors and biological activities. Through this analysis the compounds were classified into two groups active and inactive according to their degree of biological activities, and the more important properties were charges on some key atoms, electronic affinity and ClogP. (author)

  10. Synthesis, X-ray crystal structure and theoretical calculations of antileishmanial neolignan analogues

    International Nuclear Information System (INIS)

    Nascimento, Josenaide P. do; Santos, Lourivaldo S.; Carmo, Maria Carolina L. do; Brasil, Davi S.B.; Alves, Claudio N.; Santos, Regina Helena A.; Tozzo, Erica; Ferreira, Janaina G.

    2010-01-01

    The synthesis and X-ray crystal diffraction structure of two analogues of neolignans, 2-(4-chlorophenyl)-1-phenylethanone (20) and 2-[(4-chlorophenyl)thio]-1-(3,4-dimethoxyphenyl) propan-1-one (12) is described. The compound 12 presents activity against intracellular Leishmania donovani and Leishmania amazonensis amastigotes that cause cutaneous and visceral leishmaniasis. In addition, the density functional theory (DFT) with the B3LYP hybrid functional was employed to calculate a set of molecular descriptors for nineteen synthetic analogues of neolignans with antileishmanial activities. Afterwards, the stepwise discriminant analysis was performed to investigate possible relationship between the molecular descriptors and biological activities. Through this analysis the compounds were classified into two groups active and inactive according to their degree of biological activities, and the more important properties were charges on some key atoms, electronic affinity and ClogP. (author)

  11. Generating nanoparticles containing a new 4-nitrobenzaldehyde thiosemicarbazone compound with antileishmanial activity

    International Nuclear Information System (INIS)

    Aparecida Britta, Elizandra; Conceição da Silva, Cleuza; Forti Rubira, Adley; Vataru Nakamura, Celso; Borsali, Redouane

    2016-01-01

    Thiosemicarbazones are an important class of compounds that have been extensively studied in recent years, mainly because of their broad profile of pharmacological activity. A new 4-nitrobenzaldehyde thiosemicarbazone compound (BZTS) that was derived from S-limonene has been demonstrated to have significant antiprotozoan activity. However, the hydrophobic characteristic of BZTS limits its administration and results in low oral bioavailability. In the present study, we proposed the synthesis of nanoparticle-based block copolymers that can encapsulate BZTS, with morphological evaluation of the nanoparticle suspensions being performed by transmission and cryo-transmission electronic microscopy. The mean particle sizes of the nanoparticle suspensions were determined by static light and dynamic light scattering (SLS/DLS), and the hydrodynamic radius (Rh) was determined using the Stokes-Einstein equation. The zeta potential (ζ) and polydispersity index (PDI) were also determined. The entrapment encapsulation efficiency of the BZTS nanoparticles was measured by ultraviolet spectrophotometry. In vitro activity of BZTS nanoparticle suspensions against intracellular amastigotes of Leishmania amazonensis and cytotoxic activity were also evaluated. The results showed the production of spherical nanoparticles with varied sizes depending on the hydrophobic portion of the amphiphilic diblock copolymers used. Significant concentration-dependent inhibitory activity against intracellular amastigotes was observed, and low cytotoxic activity was demonstrated against macrophages. - Highlights: • The spherical nanoparticles were obtained using distinct diblock copolymers. • BZTS was successfully encapsulated in the nanoparticles. • BZTS nanoparticle suspensions presented activity in Leishmania amazonensis.

  12. Generating nanoparticles containing a new 4-nitrobenzaldehyde thiosemicarbazone compound with antileishmanial activity

    Energy Technology Data Exchange (ETDEWEB)

    Aparecida Britta, Elizandra [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Estadual de Maringá (Brazil); Conceição da Silva, Cleuza; Forti Rubira, Adley [Departamento de Química, Universidade Estadual de Maringá (Brazil); Vataru Nakamura, Celso, E-mail: cvnakamura@uem.br [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Estadual de Maringá (Brazil); Borsali, Redouane, E-mail: borsali@cermav.cnrs.fr [Centro de Pesquisas em Macromoléculas Vegetais, CERMAV, Grenoble (France)

    2016-12-01

    Thiosemicarbazones are an important class of compounds that have been extensively studied in recent years, mainly because of their broad profile of pharmacological activity. A new 4-nitrobenzaldehyde thiosemicarbazone compound (BZTS) that was derived from S-limonene has been demonstrated to have significant antiprotozoan activity. However, the hydrophobic characteristic of BZTS limits its administration and results in low oral bioavailability. In the present study, we proposed the synthesis of nanoparticle-based block copolymers that can encapsulate BZTS, with morphological evaluation of the nanoparticle suspensions being performed by transmission and cryo-transmission electronic microscopy. The mean particle sizes of the nanoparticle suspensions were determined by static light and dynamic light scattering (SLS/DLS), and the hydrodynamic radius (Rh) was determined using the Stokes-Einstein equation. The zeta potential (ζ) and polydispersity index (PDI) were also determined. The entrapment encapsulation efficiency of the BZTS nanoparticles was measured by ultraviolet spectrophotometry. In vitro activity of BZTS nanoparticle suspensions against intracellular amastigotes of Leishmania amazonensis and cytotoxic activity were also evaluated. The results showed the production of spherical nanoparticles with varied sizes depending on the hydrophobic portion of the amphiphilic diblock copolymers used. Significant concentration-dependent inhibitory activity against intracellular amastigotes was observed, and low cytotoxic activity was demonstrated against macrophages. - Highlights: • The spherical nanoparticles were obtained using distinct diblock copolymers. • BZTS was successfully encapsulated in the nanoparticles. • BZTS nanoparticle suspensions presented activity in Leishmania amazonensis.

  13. Antiparasitic effects induced by polyclonal IgY antibodies anti-phospholipase A2 from Bothrops pauloensis venom.

    Science.gov (United States)

    Borges, Isabela Pacheco; Silva, Mariana Ferreira; Santiago, Fernanda Maria; de Faria, Lucas Silva; Júnior, Álvaro Ferreira; da Silva, Rafaela José; Costa, Mônica Soares; de Freitas, Vitor; Yoneyama, Kelly Aparecida Geraldo; Ferro, Eloísa Amália Vieira; Lopes, Daiana Silva; Rodrigues, Renata Santos; de Melo Rodrigues, Veridiana

    2018-06-01

    Activities of phospholipases (PLAs) have been linked to pathogenesis in various microorganisms, and implicated in cell invasion and so the interest in these enzymes as potential targets that could contribute to the control of parasite survival and proliferation. Chicken eggs immunized with BnSP-7, a Lys49 phospholipase A 2 (PLA 2 ) homologue from Bothrops pauloensis snake venom, represent an excellent source of polyclonal antibodies with potential inhibitory activity on parasite PLA s. Herein, we report the production, characterization and anti-parasitic effect of IgY antibodies from egg yolks of hens immunized with BnSP-7. Produced antibodies presented increasing avidity and affinity for antigenic toxin epitopes throughout immunization, attaining a plateau after 4weeks. Pooled egg yolks-purified anti-BnSP-7 IgY antibodies were able to specifically recognize different PLA 2 s from Bothrops pauloensis and Bothrops jararacussu venom. Antibodies also neutralized BnSP-7 cytotoxic activity in C2C12 cells. Also, the antibodies recognized targets in Leishmania (Leishmania) amazonensis and Toxoplasma gondii extracts by ELISA and immunofluorescence assays. Anti-BnSP-7 IgY antibodies were cytotoxic to T. gondii tachyzoite and L. (L.) amazonensis promastigotes, and were able to decrease proliferation of both parasites treated before infection. These data suggest that the anti-BnSP-7 IgY is an important tool for discovering new parasite targets and blocking parasitic effects. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Genomic confirmation of hybridisation and recent inbreeding in a vector-isolated Leishmania population.

    Science.gov (United States)

    Rogers, Matthew B; Downing, Tim; Smith, Barbara A; Imamura, Hideo; Sanders, Mandy; Svobodova, Milena; Volf, Petr; Berriman, Matthew; Cotton, James A; Smith, Deborah F

    2014-01-01

    Although asexual reproduction via clonal propagation has been proposed as the principal reproductive mechanism across parasitic protozoa of the Leishmania genus, sexual recombination has long been suspected, based on hybrid marker profiles detected in field isolates from different geographical locations. The recent experimental demonstration of a sexual cycle in Leishmania within sand flies has confirmed the occurrence of hybridisation, but knowledge of the parasite life cycle in the wild still remains limited. Here, we use whole genome sequencing to investigate the frequency of sexual reproduction in Leishmania, by sequencing the genomes of 11 Leishmania infantum isolates from sand flies and 1 patient isolate in a focus of cutaneous leishmaniasis in the Çukurova province of southeast Turkey. This is the first genome-wide examination of a vector-isolated population of Leishmania parasites. A genome-wide pattern of patchy heterozygosity and SNP density was observed both within individual strains and across the whole group. Comparisons with other Leishmania donovani complex genome sequences suggest that these isolates are derived from a single cross of two diverse strains with subsequent recombination within the population. This interpretation is supported by a statistical model of the genomic variability for each strain compared to the L. infantum reference genome strain as well as genome-wide scans for recombination within the population. Further analysis of these heterozygous blocks indicates that the two parents were phylogenetically distinct. Patterns of linkage disequilibrium indicate that this population reproduced primarily clonally following the original hybridisation event, but that some recombination also occurred. This observation allowed us to estimate the relative rates of sexual and asexual reproduction within this population, to our knowledge the first quantitative estimate of these events during the Leishmania life cycle.

  15. Leishmania carbon metabolism in the macrophage phagolysosome- feast or famine?

    Science.gov (United States)

    McConville, Malcolm J; Saunders, Eleanor C; Kloehn, Joachim; Dagley, Michael J

    2015-01-01

    A number of medically important microbial pathogens target and proliferate within macrophages and other phagocytic cells in their mammalian hosts. While the majority of these pathogens replicate within the host cell cytosol or non-hydrolytic vacuolar compartments, a few, including protists belonging to the genus Leishmania, proliferate long-term within mature lysosome compartments.  How these parasites achieve this feat remains poorly defined. In this review, we highlight recent studies that suggest that Leishmania virulence is intimately linked to programmed changes in the growth rate and carbon metabolism of the obligate intra-macrophage stages. We propose that activation of a slow growth and a stringent metabolic response confers resistance to multiple stresses (oxidative, temperature, pH), as well as both nutrient limitation and nutrient excess within this niche. These studies highlight the importance of metabolic processes as key virulence determinants in Leishmania.

  16. Serological and molecular survey of Leishmania infection in dogs from Luanda, Angola

    NARCIS (Netherlands)

    Vilhena, Hugo; Granada, Sara; Oliveira, Ana Cristina; Schallig, Henk D. F. H.; Nachum-Biala, Yaarit; Cardoso, Luís; Baneth, Gad

    2014-01-01

    Canine leishmaniosis (CanL) due to Leishmania infantum is a global zoonosis endemic in more than 70 countries in Europe, North Africa, Asia and America; however, data on this infection is scarce from southern Africa. The aim of this study was to survey dogs in Luanda, Angola, for Leishmania

  17. Molecular and serological detection of Leishmania spp. in captive wild animals from Ilha Solteira, SP, Brazil Detecção sorológica e molecular de Leishmania spp. em animais selvagens do zoológico de Ilha Solteira, SP, Brasil

    Directory of Open Access Journals (Sweden)

    Márcia Mariza Gomes Jusi

    2011-09-01

    Full Text Available Leishmaniasis is a zoonotic disease that affects 12 million people worldwide. Several mammalian species can serve as a reservoir for this disease. Dogs are the main reservoir for visceral leishmaniasis in urban areas, which has become a serious public health concern in Brazil. The aim of this study was to evaluate the presence of Leishmania spp. in captive wild animals from Ilha Solteira, São Paulo, Brazil. Blood and various tissues samples were collected from animals of five different species: Speothos venaticus, Chrysocyon brachyurus, Cerdocyon thous, Pseudalopex vetulus, and Procyon cancrivorus. Antibodies against Leishmania spp. were detected in three wild canids by indirect fluorescent antibody test (IFAT and enzyme-linked immunosorbent assay (ELISA. PCR analyses of blood and bone marrow from all animals were negative, but Leishmania DNA was found in the tissues and skin of seropositive animals. Positive PCR samples were also positive for Leishmania donovani complex. Analysis of sequenced PCR products showed similarities with different regions of Leishmania (Leishmania infantum and Leishmania (Leishmania chagasi kinetoplastids. Measures to control visceral leishmaniasis in wild animals kept in Brazilian zoos should be established, as no disease control programs are currently available.Leishmaniose é uma doença zoonótica que afeta cerca de 12 milhões de pessoas no mundo todo. Várias espécies mamíferas podem servir de reservatório para a doença. Os cães são considerados os principais reservatórios para a leishmaniose visceral em áreas urbanas, o que tem se tornado um sério problema de saúde pública no Brasil. O objetivo deste trabalho foi avaliar a presença de Leishmania spp. em animais selvagens mantidos no zoológico de Ilha Solteira, São Paulo, Brasil. Foram coletados amostras de sangue e tecidos de cinco espécies diferentes: Speothos venaticus, Chrysocyon brachyurus, Cerdocyon thous, Pseudalopex vetulus, e Procyon

  18. A diagnostic assay based on variable intergenic region distinguishes between Leishmania donovani and Leishmania infantum

    Czech Academy of Sciences Publication Activity Database

    Chocholová, Eva; Jirků, Milan; Lukeš, Julius

    2008-01-01

    Roč. 55, č. 1 (2008), s. 75-78 ISSN 0015-5683 R&D Projects: GA MŠk LC07032; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : Leishmania * assay * diagnosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.307, year: 2008

  19. Detection of Leishmania spp. in Bats from an Area of Brazil Endemic for Visceral Leishmaniasis.

    Science.gov (United States)

    de Rezende, M B; Herrera, H M; Carvalho, C M E; Carvalho Anjos, E A; Ramos, C A N; de Araújo, F R; Torres, J M; de Oliveira, C E

    2017-12-01

    The multihost parasites Leishmania spp. infect a broad range of wild mammalian species including bats. Several species of bats have adapted to a variety of food resources and shelters in urban areas. This study aimed to detect Leishmania spp. DNA in bats present in forest fragments located in metropolitan areas endemic for leishmaniasis in Campo Grande, Mato Grosso do Sul (MS), Brazil. Blood samples were obtained from 80 individuals, including eight species of Phyllostomidae and one species of Vespertilionidae. Thirty of the 80 bats were positive for Leishmania spp. using conventional PCR, all belonging to the family Phyllostomidae. Eighteen samples tested by real-time PCR (qPCR) using specific primers for the kDNA of Leishmania infantum were positive. To the best of our knowledge, this is the first report detecting Leishmania spp. in Platyrrhinus incarum in addition to being the first reported detection of L. infantum in the bat species Phyllostomus discolor, Platyrrhinus lineatus, Artibeus planirostris and Artibeus lituratus. Our results show that bats can host Leishmania spp. in areas endemic for leishmaniasis, which must be taken into account in disease control operations by public health authorities. © 2017 Blackwell Verlag GmbH.

  20. Leishmania development in sand flies: parasite-vector interactions overview.

    Science.gov (United States)

    Dostálová, Anna; Volf, Petr

    2012-12-03

    Leishmaniases are vector-borne parasitic diseases with 0.9 - 1.4 million new human cases each year worldwide. In the vectorial part of the life-cycle, Leishmania development is confined to the digestive tract. During the first few days after blood feeding, natural barriers to Leishmania development include secreted proteolytic enzymes, the peritrophic matrix surrounding the ingested blood meal and sand fly immune reactions. As the blood digestion proceeds, parasites need to bind to the midgut epithelium to avoid being excreted with the blood remnant. This binding is strictly stage-dependent as it is a property of nectomonad and leptomonad forms only. While the attachment in specific vectors (P. papatasi, P. duboscqi and P. sergenti) involves lipophosphoglycan (LPG), this Leishmania molecule is not required for parasite attachment in other sand fly species experimentally permissive for various Leishmania. During late-stage infections, large numbers of parasites accumulate in the anterior midgut and produce filamentous proteophosphoglycan creating a gel-like plug physically obstructing the gut. The parasites attached to the stomodeal valve cause damage to the chitin lining and epithelial cells of the valve, interfering with its function and facilitating reflux of parasites from the midgut. Transformation to metacyclic stages highly infective for the vertebrate host is the other prerequisite for effective transmission. Here, we review the current state of knowledge of molecular interactions occurring in all these distinct phases of parasite colonization of the sand fly gut, highlighting recent discoveries in the field.

  1. Natural infection of Didelphis aurita (Mammalia: Marsupialia with Leishmania infantum in Brazil

    Directory of Open Access Journals (Sweden)

    Carreira João Carlos

    2012-06-01

    Full Text Available Abstract Background The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL. Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris, have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. Methods The opossums studied were caught by wire traps (Tomahawk in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Results Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6% and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed

  2. PKC/ROS-Mediated NLRP3 Inflammasome Activation Is Attenuated by Leishmania Zinc-Metalloprotease during Infection

    Science.gov (United States)

    Jung, Jee Yong; Chang, Kwang-Poo; Olivier, Martin

    2015-01-01

    Parasites of the Leishmania genus infect and survive within macrophages by inhibiting several microbicidal molecules, such as nitric oxide and pro-inflammatory cytokines. In this context, various species of Leishmania have been reported to inhibit or reduce the production of IL-1β both in vitro and in vivo. However, the mechanism whereby Leishmania parasites are able to affect IL-1β production and secretion by macrophages is still not fully understood. Dependent on the stimulus at hand, the maturation of IL-1β is facilitated by different inflammasome complexes. The NLRP3 inflammasome has been shown to be of pivotal importance in the detection of danger molecules such as inorganic crystals like asbestos, silica and malarial hemozoin, (HZ) as well as infectious agents. In the present work, we investigated whether Leishmania parasites modulate NLRP3 inflammasome activation. Using PMA-differentiated THP-1 cells, we demonstrate that Leishmania infection effectively inhibits macrophage IL-1β production upon stimulation. In this context, the expression and activity of the metalloprotease GP63 - a critical virulence factor expressed by all infectious Leishmania species - is a prerequisite for a Leishmania-mediated reduction of IL-1β secretion. Accordingly, L. mexicana, purified GP63 and GP63-containing exosomes, caused the inhibition of macrophage IL-1β production. Leishmania-dependent suppression of IL-1β secretion is accompanied by an inhibition of reactive oxygen species (ROS) production that has previously been shown to be associated with NLRP3 inflammasome activation. The observed loss of ROS production was due to an impaired PKC-mediated protein phosphorylation. Furthermore, ROS-independent inflammasome activation was inhibited, possibly due to an observed GP63-dependent cleavage of inflammasome and inflammasome-related proteins. Collectively for the first time, we herein provide evidence that the protozoan parasite Leishmania, through its surface

  3. Using Proteomics to Understand How Leishmania Parasites Survive inside the Host and Establish Infection.

    Science.gov (United States)

    Veras, Patrícia Sampaio Tavares; Bezerra de Menezes, Juliana Perrone

    2016-08-19

    Leishmania is a protozoan parasite that causes a wide range of different clinical manifestations in mammalian hosts. It is a major public health risk on different continents and represents one of the most important neglected diseases. Due to the high toxicity of the drugs currently used, and in the light of increasing drug resistance, there is a critical need to develop new drugs and vaccines to control Leishmania infection. Over the past few years, proteomics has become an important tool to understand the underlying biology of Leishmania parasites and host interaction. The large-scale study of proteins, both in parasites and within the host in response to infection, can accelerate the discovery of new therapeutic targets. By studying the proteomes of host cells and tissues infected with Leishmania, as well as changes in protein profiles among promastigotes and amastigotes, scientists hope to better understand the biology involved in the parasite survival and the host-parasite interaction. This review demonstrates the feasibility of proteomics as an approach to identify new proteins involved in Leishmania differentiation and intracellular survival.

  4. Molecular Characterization of Leishmania Species Isolated from Cutaneous Leishmaniasis in Yemen

    Science.gov (United States)

    Mahdy, Mohammed A. K.; Al-Mekhlafi, Hesham M.; Al-Mekhlafi, Abdulsalam M.; Lim, Yvonne A. L.; Bin Shuaib, Naemah O. M.; Azazy, Ahmed A.; Mahmud, Rohela

    2010-01-01

    Background Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in the tropics and subtropics with a global yearly incidence of 1.5 million. Although CL is the most common form of leishmaniasis, which is responsible for 60% of DALYs lost due to tropical-cluster diseases prevalent in Yemen, available information is very limited. Methodology/Principal Findings This study was conducted to determine the molecular characterization of Leishmania species isolated from human cutaneous lesions in Yemen. Dermal scrapes were collected and examined for Leishmania amastigotes using the Giemsa staining technique. Amplification of the ribosomal internal transcribed spacer 1(ITS-1) gene was carried out using nested PCR and subsequent sequencing. The sequences from Leishmania isolates were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods. The trees identified Leishmania tropica from 16 isolates which were represented by two sequence types. Conclusions/Significance The predominance of the anthroponotic species (i.e. L. tropica) indicates the probability of anthroponotic transmission of cutaneous leishmaniasis in Yemen. These findings will help public health authorities to build an effective control strategy taking into consideration person–to-person transmission as the main dynamic of transmission of CL. PMID:20862227

  5. Leishmaniasis in Turkey: Visceral and cutaneous leishmaniasis caused by Leishmania donovani in Turkey

    NARCIS (Netherlands)

    Özbilgin, Ahmet; Harman, Mehmet; Karakuş, Mehmet; Bart, Aldert; Töz, Seray; Kurt, Özgür; Çavuş, İbrahim; Polat, Erdal; Gündüz, Cumhur; van Gool, Tom; Özbel, Yusuf

    2017-01-01

    In Turkey, the main causative agents are Leishmania tropica (L. tropica) and Leishmania infantum (L. infantum) for cutaneous leishmaniasis (CL) and L. infantum for visceral leishmaniasis (VL). In this study, we investigated leishmaniasis cases caused by L. donovani and established animal models for

  6. The retained capacity of Lutzomya longipalpis (Lutz & Neiva to transmit Leishmania chagasi (Cunha & Chagas after eight years (64 generations in a closed laboratory colony

    Directory of Open Access Journals (Sweden)

    M. de N. A. Gonçalves

    1985-09-01

    Full Text Available A closed Lutzomyia longipalpis colony, from Ceará has been used to transmit Leishmania chagasi isolated from a fox in Pará state. The last time this colony was successfully used in similar transmission experiments was eight years (64 generations ago indicating that this colony of Lu. longipalpis has fully maintained its vectorial capacity in spite of such a long period of maintainance in the laboratory.Lutzomyia longipalpis foi alimentado através de membrana com uma suspensão de macerado de fígado e baço em sangue desfibrinado de coelho. Este material foi originário de um hamster infectado com Leishmania chagasi, realimentado em hamsters limpos, transmitindo os parasitos em duas ocasiões. Esta mesma colônia de Lu. longipalpis, do Ceará, foi usada para a primeira transmissão há oito anos e 64 gerações atrás e não teve a capacidade vetorial diminuída.

  7. Curcumin overcomes the inhibitory effect of nitric oxide on Leishmania.

    Science.gov (United States)

    Chan, Marion Man-Ying; Adapala, Naga Suresh; Fong, Dunne

    2005-04-01

    Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.

  8. The current status of phlebotomine sandflies (Diptera: Psychodidae) in Tunisia and their role on Leishmania transmission: A review

    OpenAIRE

    Ahmed Tabbabi; Sajida Sboui; Jabeur Daaboub

    2017-01-01

    In Tunisia, the epidemiological situation of leishmaniasis is characterized by the coexistence in a rather circumscribed territory (165000 km2, including the Sahara) of 4 forms of leishmaniasis caused by 3 species: Leishmania infantum, Leishmania major and Leishmania tropica (L. tropica) (synonymous Leishmania killicki). One of the factors determining the clinical, epidemiological and immunological diversity of leishmanioses is certainly the existence of a vector-parasite specificity of of...

  9. Comparison of Tetrazolium Salt Assays for Evaluation of Drug Activity against Leishmania spp.

    Science.gov (United States)

    Ginouves, Marine; Carme, Bernard; Couppie, Pierre

    2014-01-01

    In French Guiana, leishmaniasis is an essentially cutaneous infection. It constitutes a major public health problem, with a real incidence of 0.2 to 0.3%. Leishmania guyanensis is the causal species most frequently encountered in French Guiana. The treatment of leishmaniasis is essentially drug based, but the therapeutic compounds available have major side effects (e.g., liver damage and diabetes) and must be administered parenterally or are costly. The efficacy of some of these agents has declined due to the emergence of resistance in certain strains of Leishmania. There is currently no vaccine against leishmaniasis, and it is therefore both necessary and urgent to identify new compounds effective against Leishmania. The search for new drugs requires effective tests for evaluations of the leishmanicidal activity of a particular molecule or extract. Microculture tetrazolium assays (MTAs) are colorimetric tests based on the use of tetrazolium salts. We compared the efficacies of three tetrazolium salts—3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8)—for quantification of the promastigotes of various species of Leishmania. We found that the capacity of Leishmania to metabolize a tetrazolium salt depended on the salt used and the species of Leishmania. WST-8 was the tetrazolium salt best metabolized by L. guyanensis and gave the best sensitivity. PMID:24719447

  10. Human cutaneous leishmaniasis caused by Leishmania (Viannia braziliensis in Santiago del Estero, Argentina: identification of parasites by monoclonal antibodies and isoenzymes Leishmaniose cutânea humana causada por Leishmania (Viannia braziliensis na Província de Santiago del Estero, Argentina: identificação dos parasitas por anticorpos monoclonais e isoenzimas

    Directory of Open Access Journals (Sweden)

    C.A. Cuba Cuba

    1996-12-01

    pacientes humanos com lesões cutâneas de leishmaniose na Província de Santiago del Estero, no Norte da Argentina. Os procedimentos de diagnóstico foram: biópsias de lesões para utilização em esfregaços e inoculação em hamster; aspiração (com agulha de úlceras, para cultura "in vitro". As técnicas imunodiagnósticas empregadas foram a IFAT-IgG e o teste intradérmico de Montenegro. Oito cepas de parasitas foram isoladas, sendo estas obtidas de pacientes com lesões ativas. Todas as cepas foram inicialmente caracterizadas biologicamente por seu comportamento na infecção experimental do hamster, mensuração dos amastigotas e promastigotas e crescimento "in vitro". As mesmas oito cepas foram logo identificadas e caracterizadas a nível de espécie, devido a sua reatividade frente a um painel de anticorpos monoclonais subgênero e espécie-específicos. Isso foi realizado utilizando o teste de Imunofluorescência Indireta (IFAT/MAbs e de um procedimento de Dot-ELISA. Nós concluímos a partir da análise de serodema dos isolados argentinos que: MHOM/AR/92/SE-1; SE-2; SE-4; SE-8; SE-8-I; SE-30; SE-34 e SE-36 são Leishmania (Viannia braziliensis. Entretanto, três dos isolados de Leishmania (SE-1; SE-2 e SE-30 não foram reconhecidos quando testados com um anticorpo monoclonal de reconhecida alta espécie-especificidade (clone B-18, marcador consagrado de Leishmania (Viannia braziliensis, revelando a existência de dois tipos de serodemas entre as cepas estudadas. Cinco dos oito extratos solúveis de Leishmania foram submetidos à eletroforese em gel de amido de camada fina e subseqüentemente examinadas a fim de constatar a atividade das enzimas MPI, MDH, 6PGD, NH, NH-D, SOD, GPI e ES. Fundamentados nos estudos dos corridos eletroforéticos obtidos nos ensaios isoenzimáticos chegamos à conclusão que as cepas MHOM/AR/92 SE-1; SE-2; SE-4; SE-8 e SE-8-I são Leishmania (Viannia braziliensis. É necessário analisar mais enzimas antes de enquadrá-los nos

  11. Arginase activity in pathogenic and non-pathogenic species of Leishmania parasites.

    Science.gov (United States)

    Badirzadeh, Alireza; Taheri, Tahereh; Taslimi, Yasaman; Abdossamadi, Zahra; Heidari-Kharaji, Maryam; Gholami, Elham; Sedaghat, Baharehsadat; Niyyati, Maryam; Rafati, Sima

    2017-07-01

    Proliferation of Leishmania (L.) parasites depends on polyamine availability, which can be generated by the L-arginine catabolism and the enzymatic activity of arginase (ARG) of the parasites and of the mammalian hosts. In the present study, we characterized and compared the arginase (arg) genes from pathogenic L. major and L. tropica and from non-pathogenic L. tarentolae. We quantified the level of the ARG activity in promastigotes and macrophages infected with pathogenic L. major and L. tropica and non-pathogenic L. tarentolae amastigotes. The ARG's amino acid sequences of the pathogenic and non-pathogenic Leishmania demonstrated virtually 98.6% and 88% identities with the reference L. major Friedlin ARG. Higher ARG activity was observed in all pathogenic promastigotes as compared to non-pathogenic L. tarentolae. In vitro infection of human macrophage cell line (THP1) with pathogenic and non-pathogenic Leishmania spp. resulted in increased ARG activities in the infected macrophages. The ARG activities present in vivo were assessed in susceptible BALB/c and resistant C57BL/6 mice infected with L. major, L. tropica and L. tarentolae. We demonstrated that during the development of the infection, ARG is induced in both strains of mice infected with pathogenic Leishmania. However, in L. major infected BALB/c mice, the induction of ARG and parasite load increased simultaneously according to the time course of infection, whereas in C57BL/6 mice, the enzyme is upregulated solely during the period of footpad swelling. In L. tropica infected mice, the footpads' swellings were slow to develop and demonstrated minimal cutaneous pathology and ARG activity. In contrast, ARG activity was undetectable in mice inoculated with the non-pathogenic L. tarentolae. Our data suggest that infection by Leishmania parasites can increase ARG activity of the host and provides essential polyamines for parasite salvage and its replication. Moreover, the ARG of Leishmania is vital for parasite

  12. Surveillance for antibodies to Leishmania spp. in dogs from Sri Lanka and India

    Science.gov (United States)

    The global distribution of leishmaniasis is rapidly expanding into new geographic regions. Dogs are the primary reservoir hosts for human visceral leishmaniasis (VL) caused by infection with Leishmania infantum. Natural infections with other Leishmania species can occur in dogs, but their role as re...

  13. Application of the microscopic method in cutaneous leishmania diagnosis

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    Mohammed Wael Daboul

    2011-10-01

    Full Text Available Introduction: Cutaneous leishmania is spreading fast. This study aims at developing the microscopic method to achieve a full detection of all positive cases of leishmania.Methods: 50 human cases have been studied by applying microscopic smears stained with Wright stain. Microscopic photos were taken for the presumed unfamiliar figures.Results: Mononuclear cells with tails are present at a rate of (98%. They are associated with Leishman Donovan (LD bodies in 50% of the cases. The polygonal figures and the spherical forms are present at the same rate (60% and are associated with LD bodies in 24% of the cases. The small promastigote like forms are seen at a rate of (76% and are associated with LD bodies in 26% of the cases. The giant promastigotes like forms are present in (80% of the cases and are associated with LD bodies in 28% of the cases. Candle flame forms are present in (40% of the cases and are associated with the LD bodies in 21% of the cases.Discussion: It is applicable to use those discovered figures in diagnosing cutaneous leishmania.

  14. Phototoxic effects of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) on the viability of Leishmania major and Leishmania braziliensis promastigotes

    Science.gov (United States)

    Guerra Pinto, Juliana; Ferreira-Strixino, Juliana; Mittmann, Josane

    2016-06-01

    American cutaneous leishmaniasis (ACL) is an infectious disease caused by protozoans of the genus Leishmania. The treatment may consist of pentavalent antimonials or pentamidine and amphotericin. However, these treatments are extremely aggressive. Photodynamic antimicrobial chemotherapy (PACT) involves the same mechanism of photodynamic therapy which associates a photosensitizer with oxygen and a light source generating a photochemical reaction leading to cell death. The aim of this study was to verify the potential use of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) compound in photodynamic treatment through evaluation of its phototoxic effect in promastigotes of the genus Leishmania braziliensis and Leishmania major. Treatment with SiPc was able to drastically affect the viability of the parasites as well as affect their growth and morphology, after PACT treatment. The data shown in this study allows us to conclude that SiPc is a promising photosensitizer (PS) since it does not affect parasite growth and viability in the dark. After PACT with this phthalocyanine, over 99% of parasites were killed with the higher concentration and a light dose used. These results suggest that SiPc can be used in future to treat CL, however, further studies are necessary to determine whether the PS are toxic to mononuclear phagocytic cells and epithelial cells which will also be affected by therapy when applied topically.

  15. Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition.

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    Daniel P Depledge

    2010-09-01

    Full Text Available A family of hydrophilic acylated surface (HASP proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic and intracellular (amastigote stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia have lost HASP genes from their genomes.We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia species, L. (V. braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L. mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o HASPs are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family.These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are

  16. Effect of Kelussia odoratissima Mozaff essential oil on promastigot form of Leishmania major (in vitro)

    OpenAIRE

    Pirali Kheirabadi Khodadad; Saei Dehkordi Siavash; Kheibari Parviz

    2015-01-01

    Introduction: Leishmaniasis is a zoonotic disease caused by a protozoan of the genus Leishmania. In this study, the effects of Kelussia odoratissima Mozaff essential oil on the promastigot form of Leishmania major were studied. Methods: In this study, the effects of Kelussia odoratissima Mozaff essential oil on the promastigot form of Leishmania major were assessed by calculating the average number of surviving promastigots after exposure to different concentrations of essential oil, relativ...

  17. Sand fly-Leishmania interactions: long relationships are not necessarily easy

    OpenAIRE

    Ramalho-Ortigao, Marcelo; Saraiva, Elvira M.; Traub-Csekö, Yara M.

    2010-01-01

    Sand fly and Leishmania are one of the best studied vector-parasite models. Much is known about the development of these parasites within the sand fly, and how transmission to a suitable vertebrate host takes place. Various molecules secreted by the vector assist the establishment of the infection in a vertebrate, and changes to the vector are promoted by the parasites in order to facilitate or enhance transmission. Despite a generally accepted view that sand flies and Leishmania are also one...

  18. Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection.

    Science.gov (United States)

    Glennie, Nelson D; Yeramilli, Venkata A; Beiting, Daniel P; Volk, Susan W; Weaver, Casey T; Scott, Phillip

    2015-08-24

    Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. © 2015 Glennie et al.

  19. The development of Leishmania turanica in sand flies and competition with L. major.

    Science.gov (United States)

    Chajbullinova, Alsu; Votypka, Jan; Sadlova, Jovana; Kvapilova, Katerina; Seblova, Veronika; Kreisinger, Jakub; Jirku, Milan; Sanjoba, Chizu; Gantuya, Sambuu; Matsumoto, Yoshitsugu; Volf, Petr

    2012-10-02

    In Central Asian foci of zoonotic cutaneous leishmaniases, mixed infections of Leishmania turanica and L. major have been found in a reservoir host (the great gerbil, Rhombomys opimus) as well as in the sand fly vector Phlebotomus papatasi, but hybrids between these two Leishmania species have never been reported. In addition, the role of sand fly species other than P. papatasi in L. turanica circulation is not clear. In this work we compared the development of L. turanica in three sand fly species belonging to different subgenera. In addition, we studied experimental co-infections of sand flies by both Leishmania species using GFP transfected L. turanica (MRHO/MN/08/BZ18(GFP+)) and RFP transfected L. major (WHOM/IR/-/173-DsRED(RFP+)). The possibility of Leishmania genetic exchange during the vectorial part of the life cycle was studied using flow cytometry combined with immunofluorescent microscopy. Late-stage infections of L. turanica with frequent colonization of the stomodeal valve were observed in the specific vector P. (Phlebotomus) papatasi and in the permissive vector P. (Adlerius) arabicus. On the other hand, in P. sergenti (the specific vector of L. tropica), L. turanica promatigotes were present only until the defecation of bloodmeal remnants. In their natural vector P. papatasi, L. turanica and L. major developed similarly, and the spatiotemporal dynamics of localization in the sand fly gut was the same for both leishmania species. Fluorescence microscopy in combination with FACS analyses did not detect any L. major / L. turanica hybrids in the experimental co-infection of P. papatasi and P. duboscqi. Our data provide new insight into the development of different leishmania parasite species during a mixed infection in the sand fly gut. Despite the fact that both Leishmania species developed well in P. papatasi and P. duboscqi and did not outcompete each other, no genetic exchange was found. However, the ability of L. turanica to establish late

  20. Leishmania chagasi/infantum : further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America

    NARCIS (Netherlands)

    Campos Ponce, M.; Ponce, C.; Ponce, E; Maingon, R.D.

    2005-01-01

    In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran

  1. Leishmania chagasi/infantum: further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America.

    NARCIS (Netherlands)

    Campos Ponce, M.; Ponce, C.; Ponce, E.; Maingon, R.D.

    2005-01-01

    In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran

  2. Dynamics of sterol synthesis during development of Leishmania spp. parasites to their virulent form.

    Science.gov (United States)

    Yao, Chaoqun; Wilson, Mary E

    2016-04-12

    The Leishmania spp. protozoa, the causative agents of the "neglected" tropical disease leishmaniasis, are transmitted to mammals by sand fly vectors. Within the sand fly, parasites transform from amastigotes to procyclic promastigotes, followed by development of virulent (metacyclic) promastigote forms. The latter are infectious to mammalian hosts. Biochemical components localized in the parasite plasma membrane such as proteins and sterols play a pivotal role in Leishmania pathogenesis. Leishmania spp. lack the enzymes for cholesterol synthesis, and the dynamics of sterol acquisition and biosynthesis in parasite developmental stages are not understood. We hypothesized that dynamic changes in sterol composition during metacyclogenesis contribute to the virulence of metacyclic promastigotes. Sterols were extracted from logarithmic phase or metacyclic promastigotes grown in liquid culture with or without cholesterol, and analyzed qualitatively and quantitatively by gas chromatograph-mass spectrometry (GC-MS). TriTrypDB was searched for identification of genes involved in Leishmania sterol biosynthetic pathways. In total nine sterols were identified. There were dynamic changes in sterols during promastigote metacyclogenesis. Cholesterol in the culture medium affected sterol composition in different parasite stages. There were qualitative and relative quantitative differences between the sterol content of virulent versus avirulent parasite strains. A tentative sterol biosynthetic pathway in Leishmania spp. promastigotes was identified. Significant differences in sterol composition were observed between promastigote stages, and between parasites exposed to different extracellular cholesterol in the environment. These data lay the foundation for further investigating the role of sterols in the pathogenesis of Leishmania spp. infections.

  3. Observações sobre calazar em Jacobina, Bahia. VI - Investigações sobre reservatórios silvestres e comensais

    Directory of Open Access Journals (Sweden)

    I. A. Sherlock

    1988-03-01

    Full Text Available Durante os anos de 1982 a 1986, a investigação sobre mamíferos comensais e silvestres, da periferia da cidade de Jacobina, Bahia, mostrou, ao lado do escasso número de exemplares, uma reduzida variedade específica dessa fauna. Capturou-se apenas 11 espécies, entre as quais, predominou o Didelphis albiventris, que abrangeu 44% dos 213 espécimens capturados. Entre os 193 com exames já concluídos, 84 eram exemplares de D. albiventris e 2 estavam infectados pela Leishmania donovani senso lato, 1 por L. mexicana amazonensis, 1 por L. braziliensis, subespécie e 3 por Trypanosoma cruzi Também foram observadas formas suspeitas de serem amastigotas de leishmanics, nos esfregaços de órgãos de 3 exemplares de Dasyprocta aguti, 1 Cercomys cunicularius - e 1 Oryzomys eliurus. 0 restante dos exemplares, inclusive 14 de Lycalopex vetulus, estava negativo para flagelados. Apesar de reforçado por outros indicadores epidemiológicos, como a predominância específica, a freqüência domiciliar, a atratividade para a vetora Lutzomyia longipalpis, e a concomitância com casos humanos nos mesmos locais, o índice de 2,3% de infecção natural do Didelphis albiventris, não autoriza a conclusão definitiva de ser o marsupial o mais importante reservatório natural da leishmaniose visceral em Jacobina.

  4. Presence of anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. and -Ehrlichia canis antibodies in free-ranging maned wolves (Chrysocyon brachyurus in the northeastern region of the state of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Solange Oliveira

    2016-09-01

    Full Text Available O lobo-guará (Chrysocyon brachyurus habita o ecossistema de Cerrado e é considerado o maior canídeo da América do Sul e uma espécie ameaçada de extinção pela "International Union for Conservation of Nature" (IUNC. O objetivo desse estudo foi investigar a presença de anticorpos anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. e -Ehrlichia canis em lobos-guará da região nordeste do estado de São Paulo, Brasil. Das 17 amostras de soro testadas por meio da reação de imunofluorescência indireta (RIFI, 88,2% (15/17, 17,6% (3/17 e 52,9% (9/17 apresentaram anticorpos anti-T. gondii, -Leishmania spp. e -E. canis, respectivamente. Todos os animais testados foram soronegativos para N. caninum. Esses resultados indicam a exposição dos lobos-guará dessa região aos agentes pesquisados. A presença de um complexo industrial, agricultura extensiva e fragmentação de habitat na região nordeste do estado de São Paulo, favorece a proximidade desses animais silvestres a ambientes urbanos o que pode contribuir para a transmissão de doenças entre os animais silvestres, domésticos e o homem.

  5. Changes in Macrophage Gene Expression Associated with Leishmania (Viannia braziliensis Infection.

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    Clemencia Ovalle-Bracho

    Full Text Available Different Leishmania species cause distinct clinical manifestations of the infectious disease leishmaniasis. It is fundamentally important to understand the mechanisms governing the interaction between Leishmania and its host cell. Little is known about this interaction between Leishmania (Viannia braziliensis and human macrophages. In this study, we aimed to identify differential gene expression between non-infected and L. (V braziliensis-infected U937-derived macrophages. We deployed a whole human transcriptome microarray analysis using 72 hours post-infection samples and compared those samples with their non-infected counterparts. We found that 218 genes were differentially expressed between infected and non-infected macrophages. A total of 71.6% of these genes were down-regulated in the infected macrophages. Functional enrichment analyses identified the steroid and sterol/cholesterol biosynthetic processes between regulatory networks down-regulated in infected macrophages. RT-qPCR further confirmed this down-regulation in genes belonging to these pathways. These findings contrast with those from studies involving other Leishmania species at earlier infection stages, where gene up-regulation for this metabolic pathway has been reported. Sterol biosynthesis could be an important biological process associated with the expression profile of macrophages infected by L. (V. braziliensis. Differential transcriptional results suggest a negative regulation of the genetic regulatory network involved in cholesterol biosynthesis.

  6. Impact of Leishmania mexicana infection on dendritic cell signaling and functions.

    Directory of Open Access Journals (Sweden)

    Irazú Contreras

    2014-09-01

    Full Text Available Leishmania parasites have the ability to modify macrophage signaling pathways in order to survive and multiply within its mammalian host. They are also known to invade other cells including neutrophils, fibroblasts and dendritic cells (DCs. DCs have an important role in immunity as the link between innate and adaptive immunity, necessary for the development of an effective response; however, the impact of Leishmania mexicana infection on DCs has been poorly studied. Herein, we report that Leishmania infection rapidly induced DC protein tyrosine phosphatases activity, leading to MAP kinases inactivation. In line with this, L. mexicana was found to decrease the nuclear translocation of transcription factors such as AP-1 and NF-κB. Concomitantly, L. mexicana-infected DCs showed reduced expression of several surface antigen-presenting and co-stimulatory molecules upon LPS stimulation. Leishmania-induced interference on DC maturation was further reflected by their reduced capacity to present OVA antigen to OVA-specific T cells, as shown by abrogation of IL-2 production by the T cells. Collectively, our data revealed that DC infection by L. mexicana appears to affect the cellular and immunological mechanisms necessary for the development of an effective and protective immune response, therefore favouring the survival and propagation of the parasite within its host.

  7. Riesgo de transmisión de Leishmania (Kinetoplastida: Trypanosomatidae en Mérida Venezuela

    Directory of Open Access Journals (Sweden)

    Elsa Nieves

    2014-09-01

    Full Text Available La leishmaniasis es una enfermedad causada por la infección de un parásito protozoario del género Leishmania, transmitido por la picada de insectos hematófagos conocidos como flebotominos. El estudio tiene como objetivo determinar la presencia de flebotominos en los Distritos Sanitarios del estado Mérida y diseñar un mapa de riesgo de transmisión entomológico. Se utilizaron cuatro métodos de captura de flebotominos, los ejemplares se identificaron y se les determinó la infección natural por Leishmania. Se estimó la riqueza de especies, y se realizó un proceso analítico Jerárquico. Los resultados muestran la presencia de diversas especies de flebotominos en los Distritos Sanitarios del estado Mérida, siendo las especies de mayor frecuencia L. youngi, L. gomezi, L. ovallesi y L. walkeri. Se detectó 2,1% de infección natural con Leishmania, la cual se encontró en las 4 especies más frecuentes. Se presenta un mapa de riesgo de transmisión entomológico para el estado Mérida. El conocimiento de la situación actual de los vectores de Leishmania en el estado Mérida y el riesgo de transmisión son relevantes a la hora de considerar la prevención y posible surgimiento de nuevos brotes de leishmaniasis. Abstract (english The leishmaniasis is a disease caused by infection with a protozoan parasite of the genus Leishmania, transmitted by the bite of blood-sucking insects known as sandflies. The study aims to determine the presence of sandflies in Merida state health districts and design a map of entomological risk of transmission. Four methods capture sandflies were used, the specimens were identified and natural Leishmania infection was determined. The richness species was estimated and analityc Hierarchie procesess was performed. The results show the presence of various species of sandflies in Merida state health districts, L. youngi, L. gomezi, L. ovallesi and L. walkeri were most abundant species. The 2.1% of natural infection

  8. Leishmania infantum ecto-nucleoside triphosphate diphosphohydrolase-2 is an apyrase involved in macrophage infection and expressed in infected dogs.

    Directory of Open Access Journals (Sweden)

    Raphael De Souza Vasconcellos

    2014-11-01

    Full Text Available Visceral leishmaniasis is an important tropical disease, and Leishmania infantum chagasi (synonym of Leishmania infantum is the main pathogenic agent of visceral leishmaniasis in the New World. Recently, ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases were identified as enablers of infection and virulence factors in many pathogens. Two putative E-NTPDases (∼70 kDa and ∼45 kDa have been found in the L. infantum genome. Here, we studied the ∼45 kDa E-NTPDase from L. infantum chagasi to describe its natural occurrence, biochemical characteristics and influence on macrophage infection.We used live L. infantum chagasi to demonstrate its natural ecto-nucleotidase activity. We then isolated, cloned and expressed recombinant rLicNTPDase-2 in bacterial system. The recombinant rLicNTPDase-2 hydrolyzed a wide variety of triphosphate and diphosphate nucleotides (GTP> GDP  =  UDP> ADP> UTP  =  ATP in the presence of calcium or magnesium. In addition, rLicNTPDase-2 showed stable activity over a pH range of 6.0 to 9.0 and was partially inhibited by ARL67156 and suramin. Microscopic analyses revealed the presence of this protein on cell surfaces, vesicles, flagellae, flagellar pockets, kinetoplasts, mitochondria and nuclei. The blockade of E-NTPDases using antibodies and competition led to lower levels of parasite adhesion and infection of macrophages. Furthermore, immunohistochemistry showed the expression of E-NTPDases in amastigotes in the lymph nodes of naturally infected dogs from an area of endemic visceral leishmaniasis.In this work, we cloned, expressed and characterized the NTPDase-2 from L. infantum chagasi and demonstrated that it functions as a genuine enzyme from the E-NTPDase/CD39 family. We showed that E-NTPDases are present on the surface of promastigotes and in other intracellular locations. We showed, for the first time, the broad expression of LicNTPDases in naturally infected dogs. Additionally, the blockade of

  9. Leishmania infantum Ecto-Nucleoside Triphosphate Diphosphohydrolase-2 is an Apyrase Involved in Macrophage Infection and Expressed in Infected Dogs

    Science.gov (United States)

    Vasconcellos, Raphael De Souza; Mariotini-Moura, Christiane; Gomes, Rodrigo Saar; Serafim, Tiago Donatelli; Firmino, Rafaela de Cássia; Silva e Bastos, Matheus; de Castro, Felipe Freitas; de Oliveira, Claudia Miranda; Borges-Pereira, Lucas; de Souza, Anna Cláudia Alves; de Souza, Ronny Francisco; Gómez, Gabriel Andres Tafur; Pinheiro, Aimara da Costa; Maciel, Talles Eduardo Ferreira; Silva-Júnior, Abelardo; Bressan, Gustavo Costa; Almeida, Márcia Rogéria; Baqui, Munira Muhammad Abdel; Afonso, Luís Carlos Crocco; Fietto, Juliana Lopes Rangel

    2014-01-01

    Background Visceral leishmaniasis is an important tropical disease, and Leishmania infantum chagasi (synonym of Leishmania infantum) is the main pathogenic agent of visceral leishmaniasis in the New World. Recently, ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) were identified as enablers of infection and virulence factors in many pathogens. Two putative E-NTPDases (∼70 kDa and ∼45 kDa) have been found in the L. infantum genome. Here, we studied the ∼45 kDa E-NTPDase from L. infantum chagasi to describe its natural occurrence, biochemical characteristics and influence on macrophage infection. Methodology/Principal Findings We used live L. infantum chagasi to demonstrate its natural ecto-nucleotidase activity. We then isolated, cloned and expressed recombinant rLicNTPDase-2 in bacterial system. The recombinant rLicNTPDase-2 hydrolyzed a wide variety of triphosphate and diphosphate nucleotides (GTP> GDP  =  UDP> ADP> UTP  =  ATP) in the presence of calcium or magnesium. In addition, rLicNTPDase-2 showed stable activity over a pH range of 6.0 to 9.0 and was partially inhibited by ARL67156 and suramin. Microscopic analyses revealed the presence of this protein on cell surfaces, vesicles, flagellae, flagellar pockets, kinetoplasts, mitochondria and nuclei. The blockade of E-NTPDases using antibodies and competition led to lower levels of parasite adhesion and infection of macrophages. Furthermore, immunohistochemistry showed the expression of E-NTPDases in amastigotes in the lymph nodes of naturally infected dogs from an area of endemic visceral leishmaniasis. Conclusions/Significance In this work, we cloned, expressed and characterized the NTPDase-2 from L. infantum chagasi and demonstrated that it functions as a genuine enzyme from the E-NTPDase/CD39 family. We showed that E-NTPDases are present on the surface of promastigotes and in other intracellular locations. We showed, for the first time, the broad expression of LicNTPDases in

  10. Leishmaniosis cutanea: manifestación clínica inusual

    Directory of Open Access Journals (Sweden)

    Aidé Sandoval-Juárez

    Full Text Available Las manifestaciones clínicas de la leishmaniosis son variables y están relacionadas con la especie infectante, su relación con el medioambiente y con la respuesta inmune del hospedero. Se presenta un caso de leishmaniosis andina cutánea tardía con una manifestación extensa. El caso se confirmó a través de estudios microbiológicos e inmunológicos, la identificación se realizó mediante secuenciamiento del gen del citocromo b, determinándose la especie como Leishmania (Leishmania amazonensis. La paciente recibió tratamiento con estibogluconato sódico y al término de la terapia, mostró mejoría clínica de las lesiones. Se recomienda considerar a la leishmaniosis en el diagnóstico diferencial cuando se atienda ulceras crónicas dermatológicas atípicas.

  11. Sandfly saliva of Lutzomyia ovallesi (Diptera: Psychodidae) as a possible marker for the transmission of Leishmania in Venezuela Andes region.

    Science.gov (United States)

    Nieves, E; Sánchez, Y; Sánchez, H; Rondón, M; González, N; Carrero, J

    2012-03-01

    The saliva of the Phlebotominae is highly immunogenic to the vertebrate host and is a determining factor in the Leishmania infection. The aim of this work was to study the saliva of Lutzomyia ovallesi as a possible risk marker for the transmission of Leishmania. Two populations of L. ovallesi from different geographical areas and subjected to different environmental conditions were compared by geometric morphometry of the wings, by protein profile analysis of salivary glands and by assessing the presence of anti-saliva protein in human sera confronted with laboratory L. ovallesi saliva. The results showed differences in the isometric size and structure of the wings but no allometric effects. Protein profiles of salivary glands of both the L. ovallesi populations studied were found to be similar, based on 11 protein bands with molecular weights ranging from 16 to 99 kDa. Anti-saliva antibodies were present in human sera, but human sera infected and uninfected with leishmaniasis could not be differentiated. We conclude that the saliva of laboratory-reared L. ovallesi is representative of that of the wild population. It is suggested to study the presence of anti-saliva antibodies in other species of sandflies and mosquitoes.

  12. Antileishmanial activity of licochalcone A in mice infected with Leishmania major and in hamsters infected with Leishmania donovani

    DEFF Research Database (Denmark)

    Chen, M; Christensen, S B; Theander, T G

    1994-01-01

    This study was designed to examine the antileishmanial activity of the oxygenated chalcone licochalcone A in mice and hamsters infected with Leishmania parasites. Intraperitoneal administration of licochalcone A at doses of 2.5 and 5 mg/kg of body weight per day completely prevented lesion...... development in BALB/c mice infected with Leishmania major. Treatment of hamsters infected with L. donovani with intraperitoneal administration of licochalcone A at a dose of 20 mg/kg of body weight per day for 6 consecutive days resulted in a > 96% reduction of parasite load in the liver and the spleen...... consecutive days resulted in > 65 and 85% reductions of L. donovani parasite loads in the liver and the spleen, respectively, compared with those of untreated control hamsters. These data clearly demonstrate that licochalcone A is a promising lead for the development of a new drug against leishmaniases....

  13. Characterization of monomeric DNA-binding protein Histone H1 in Leishmania braziliensis.

    Science.gov (United States)

    Carmelo, Emma; González, Gloria; Cruz, Teresa; Osuna, Antonio; Hernández, Mariano; Valladares, Basilio

    2011-08-01

    Histone H1 in Leishmania presents relevant differences compared to higher eukaryote counterparts, such as the lack of a DNA-binding central globular domain. Despite that, it is apparently fully functional since its differential expression levels have been related to changes in chromatin condensation and infectivity, among other features. The localization and the aggregation state of L. braziliensis H1 has been determined by immunolocalization, mass spectrometry, cross-linking and electrophoretic mobility shift assays. Analysis of H1 sequences from the Leishmania Genome Database revealed that our protein is included in a very divergent group of histones H1 that is present only in L. braziliensis. An antibody raised against recombinant L. braziliensis H1 recognized specifically that protein by immunoblot in L. braziliensis extracts, but not in other Leishmania species, a consequence of the sequence divergences observed among Leishmania species. Mass spectrometry analysis and in vitro DNA-binding experiments have also proven that L. braziliensis H1 is monomeric in solution, but oligomerizes upon binding to DNA. Finally, despite the lack of a globular domain, L. braziliensis H1 is able to form complexes with DNA in vitro, with higher affinity for supercoiled compared to linear DNA.

  14. Serological and molecular survey of Leishmania infection in dogs from Luanda, Angola.

    Science.gov (United States)

    Vilhena, Hugo; Granada, Sara; Oliveira, Ana Cristina; Schallig, Henk D F H; Nachum-Biala, Yaarit; Cardoso, Luís; Baneth, Gad

    2014-03-24

    Canine leishmaniosis (CanL) due to Leishmania infantum is a global zoonosis endemic in more than 70 countries in Europe, North Africa, Asia and America; however, data on this infection is scarce from southern Africa. The aim of this study was to survey dogs in Luanda, Angola, for Leishmania infection. One hundred-and-three dogs presented to a veterinary medical centre in Luanda were serologically and molecularly assessed for Leishmania with the direct agglutination test (DAT) and polymerase chain reaction (PCR). Two dogs were seropositive, with DAT titres of 800 and ≥6400; the latter was also found to be PCR-positive and confirmed to be infected with L. infantum by DNA sequence analysis. No other dog was found to be PCR-positive. The first dog had been imported from Portugal, but the latter had never left Angola (neither had its parents), strongly suggesting an autochthonous infection. Although other cases of CanL have previously been described in the country, this is the first reported study of canine Leishmania infection at the population level, as well as the first report on the molecular characterization of L. infantum in dogs from Angola.

  15. Cloning, expression, purification and characterization of Leishmania tropica PDI-2 protein

    Directory of Open Access Journals (Sweden)

    Ali Dina

    2016-01-01

    Full Text Available In Leishmania species, protein disulfide isomerase (PDI is an essential enzyme that catalyzes thiol-disulfide interchange. The present work describes the isolation, cloning, sequencing and expression of the pdI-2 gene. Initially, the gene was amplified from L. tropica genomic DNA by PCR using specific primers before cloning into the expression vector pET-15b. The construct pET/pdI-2 was transformed into BL21(DE3 cells and induced for the protein expression. SDS-PAGE and western blot analysis showed that the expressed protein is about 51 kDa. Cloned gene sequence analysis revealed that the deduced amino acid sequence showed significant homology with those of several parasites PDIs. Finally, recombinant protein was purified with a metal-chelating affinity column. The putative protein was confirmed as a thiol - disulfide oxidoreductase by detecting its activity in an oxidoreductase assay. Assay result of assay suggested that the PDI-2 protein is required for both oxidation and reduction of disulfide bonds in vitro. Antibodies reactive with this 51 kDa protein were detected by Western blot analysis in sera from human infected with L. tropica. This work describes for the first time the enzymatic activity of recombinant L. tropica PDI-2 protein and suggests a role for this protein as an antigen for the detection of leishmaniasis infection.

  16. Morphology and small subunit rDNA-based phylogeny of Ceratomyxa amazonensis n. sp. parasite of Symphysodon discus, an ornamental freshwater fish from Amazon.

    Science.gov (United States)

    Mathews, Patrick D; Naldoni, Juliana; Maia, Antonio A; Adriano, Edson A

    2016-10-01

    The specious genus Ceratomyxa Thélodan, 1892, infect mainly gallbladder of marine fishes, with only five species reported infecting species from freshwater environment. This study performed morphological and phylogenetic analyses involving a new Ceratomyxa species (Ceratomyxa amazonensis n. sp.) found in gallbladder of Symphysodon discus Heckel, 1840 (Perciformes: Cichlidae), an important ornamental fish endemic to Amazon basin. Mature spores were strongly arcuate shaped and measured 7.0 ± 0.3 (6.2-7.6) μm in length, 15.8 ± 0.4 (15.0-16.7) μm in thickness, and polar capsules 3.22 ± 0.34 (2.4-3.6) μm in length and 2.63 ± 0.17 (2.4-2.9) μm in width. This was the first small subunit ribosomal DNA (SS rDNA) sequencing performed to Ceratomyxa species parasite of freshwater fish, and the phylogenetic analysis showed C. amazonensis n. sp. clustering in the early diverging subclade of the ceratomyxids, together with species of parasites of amphidromous/estuaries fishes, suggesting some role of the transition of the fishes between marine/freshwater environments in the evolutionary history of these parasites.

  17. Improved Antileishmanial Activity of Dppz through Complexation with Antimony(III and Bismuth(III: Investigation of the Role of the Metal

    Directory of Open Access Journals (Sweden)

    Cynthia Demicheli

    2012-10-01

    Full Text Available Two novel trivalent antimony(III and bismuth(III complexes with the nitrogen-donor heterocyclic ligand dipyrido[3,2-a:2',3'-c]phenazine (dppz were synthesized and characterized as [Sb(dppzCl3]∙H2O∙CH3OH and [Bi(dppzCl3]. The crystal structure of Sb(III complex was determined by X-ray crystallography. These complexes were evaluated for their activity against the promastigote form of Sb(III-sensitive and –resistant Leishmania infantum chagasi and Leishmania amazonensis strains. Both complexes were more effective than dppz alone in inhibiting the growth of Leishmania promastigotes and were at least 77 and 2,400 times more active than potassium antimonyl tartrate in Sb(III-sensitive and -resistant Leishmania, respectively. The cytotoxicity of dppz and its complexes against mouse peritoneal macrophages occurred at dppz concentrations at least 6-fold greater than those found to be active against Leishmania promastigotes.To investigate the role of the metal in the improved antileishmanial activity of dppz, the activity of the Sb(III complex was compared between the Sb-resistant mutants and their respective parental sensitive strains. The lack of cross-resistance to the Sb(III-dppz complex together with the much lower activity of antimonyl tartrate, SbCl3 and BiCl3 strongly support the model that the metal is not active by itself but improves the activity of dppz through complexation.

  18. Detection of Leishmania parasites in the blood of patients with isolated cutaneous leishmaniasis.

    Science.gov (United States)

    Nakkash-Chmaisse, Hania; Makki, Raja; Nahhas, Georges; Knio, Khouzama; Nuwayri-Salti, Nuha

    2011-07-01

    The consequences of the spread of Leishmania parasites to the blood from lesions in patients with cutaneous leishmaniasis are numerous. To assess the magnitude of this invasion we conducted the present study on patients referred to the American University of Beirut Medical Center for cutaneous leishmaniasis. Patients referred for the management of cutaneous leishmaniasis were included in the study. Skin and blood cultures for Leishmania were taken from these patients. One hundred sixty-two patients were proven to have cutaneous leishmaniasis by pathology; 52% were males and 44% females (gender information was missing for 4%). Patient age ranged from 5 months to 70 years. None of the patients had received treatment for Leishmania. We obtained parasite isolates from 85 patients (52.5%), proven by cultures from skin and blood/blood components. Interestingly, the parasite was isolated in the blood and blood components of 50 patients (30.9%). Isoenzyme analysis confirmed the fact that the organisms in blood and skin were the same; from the 28 isolates that were positive in both skin and blood, eight isolates were Leishmania major and two were Leishmania tropica. The remaining isolates, whether positive in both blood and skin or in either of these tissues, skin or blood and its products, were Leishmania infantum sensu lato. In the current study, the detection rate of parasites in the blood of patients with cutaneous leishmaniasis was high. This illustrates the invasive characteristic of the parasite that has escaped the skin. Testing should be considered in areas other than Lebanon, especially around the Mediterranean basin. Whether these findings support the administration of systemic treatment for cutaneous leishmaniasis or not needs to be confirmed in larger prospective studies. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  19. Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures.

    Science.gov (United States)

    Fernandes, Maria Cecilia; Dillon, Laura A L; Belew, Ashton Trey; Bravo, Hector Corrada; Mosser, David M; El-Sayed, Najib M

    2016-05-10

    Macrophages are mononuclear phagocytes that constitute a first line of defense against pathogens. While lethal to many microbes, they are the primary host cells of Leishmania spp. parasites, the obligate intracellular pathogens that cause leishmaniasis. We conducted transcriptomic profiling of two Leishmania species and the human macrophage over the course of intracellular infection by using high-throughput RNA sequencing to characterize the global gene expression changes and reprogramming events that underlie the interactions between the pathogen and its host. A systematic exclusion of the generic effects of large-particle phagocytosis revealed a vigorous, parasite-specific response of the human macrophage early in the infection that was greatly tempered at later time points. An analogous temporal expression pattern was observed with the parasite, suggesting that much of the reprogramming that occurs as parasites transform into intracellular forms generally stabilizes shortly after entry. Following that, the parasite establishes an intracellular niche within macrophages, with minimal communication between the parasite and the host cell later during the infection. No significant difference was observed between parasite species transcriptomes or in the transcriptional response of macrophages infected with each species. Our comparative analysis of gene expression changes that occur as mouse and human macrophages are infected by Leishmania spp. points toward a general signature of the Leishmania-macrophage infectome. Little is known about the transcriptional changes that occur within mammalian cells harboring intracellular pathogens. This study characterizes the gene expression signatures of Leishmania spp. parasites and the coordinated response of infected human macrophages as the pathogen enters and persists within them. After accounting for the generic effects of large-particle phagocytosis, we observed a parasite-specific response of the human macrophages early in

  20. Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

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    Marie Samanovic

    2009-01-01

    Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

  1. Infección de fibroblastos de piel de animales con distinto grado de susceptibilidad a Leishmania infantum y Leishmania mexicana (Kinetoplastida: Trypanosomatidae

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    Miguel Angel Minero

    2004-03-01

    Full Text Available En este estudio se presenta un modelo in vitro de cultivo de fibroblastos de piel de hámster, ratón y rata hecho con el propósito de determinar diferencias en cuanto a la susceptibilidad a la infección por dos especies del género Leishmania (Kinetoplastida: Trypanosomatidae. Se realizó además un estudio ultraestructural por microscopía electrónica de transmisión con el fin de establecer si las formas intracelulares observadas correspondían a multiplicación interna o a fagocitosis múltiple. Se estudió la multiplicación de los parásitos en los fibroblastos de las tres especies de roedores infectados tanto por Leishmania infantum como por L. mexicana (cepa OCR y las diferencias entre las tres fueron estadísticamente significativas (pInfection and multiplication of Leishmania infantum and L. mexicana inside of skin fibroblasts from hamsters, mice and rats was achieved. This process was demonstrated either by counting parasites inside the stained cells or by electronic microscopy studies. In addition multiplication rate differences in the cells from these rodent species were determined, for L. infantum as well as for L. mexicana. Parasite development in hamsters and mice fibroblasts was evident but there was not multiplication in rat cells showing that apparently they are refractory to Leishmania infection. These results suggest that the parasite affinity for each animal, as well as any intracellular environment resistance, could involve genetic factors in the parasite multiplication. On the other hand, presence of amastigote multiplication inside of parasitophorus vacuole, showed by electronic microscopy images, probes a true parasite transformation. Therefore it is suggested that fibroblasts could work as host cells for parasite survival and permanency in the infected animals

  2. Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin

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    Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d’ El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington LC

    2015-01-01

    Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55–89] μm2 for uninfected and 41 [34–51] μm2 for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm2 s−1 ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm2 s−1 ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis. PMID:26249106

  3. Disseminated Leishmaniasis Caused by Leishmania Tropica in a Puppy from Karaj, Central Iran

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    M Mohebali

    2011-06-01

    Full Text Available A 5-month old puppy with muco-cutaneous lesions in the chin, around lips and eyes was exam­ined physically and microscopically for leishmaniasis. Muco-cutaneous lesions containing a large num­ber of amastigotes of Leishmania spp. were observed. Amastigotes were also detected in liver and spleen of the puppy. The animal was positive with Dipstick rK39 kit and high level of anti-Leishmania antibodies was detected by direct agglutination test (DAT. DNA, Using PCR-RFLP technique extracted from cultured Leishmania promastigotes and L. tropica was identified. This is the first report of concurrent mucosal and visceral involvement of L. tropica in a puppy from Iran.

  4. Cyclic nucleotide specific phosphodiesterases of Leishmania major

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    Linder Markus

    2006-03-01

    Full Text Available Abstract Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range

  5. Canine cutaneous leishmaniasis caused by neotropical Leishmania infantum despite of systemic disease: A case report.

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    Cavalcanti, Amanda; Lobo, Rogério; Cupolillo, Elisa; Bustamante, Fábio; Porrozzi, Renato

    2012-12-01

    Visceral leishmaniasis is an anthropozoonosis caused by a protozoan Leishmania infantum (syn. Leishmania chagasi). Here, we report a typical case of canine cutaneous leishmaniasis due to L. infantum infection without any other systemic symptom in one dog in the city of Rio de Janeiro, Brazil. A mongrel female dog was admitted in a veterinary clinic with reports of chronic wounds in the body. Physical examination revealed erosive lesions in the limbs, nasal ulcers, presence of ectoparasites and seborrheic dermatitis. Blood samples and fragments of healthy and injured skin were collected. The complete hemogram revealed aregenerative normocytic normochromic anemia and erythrocyte rouleaux, and biochemical analysis revealed normal renal and hepatic functions. Cytology of the muzzle and skin lesions suggested pyogranulomatous inflammatory process. The histopathology of a skin fragment was performed and revealed suspicion of protozoa accompanied by necrotizing dermatitis. The diagnosis of leishmaniasis was accomplished by positive serology, isolation of Leishmania from the skin lesion, and also by molecular test (PCR targeting the conserved region of Leishmania kDNA). Culture was positive for damaged skin samples. PCR targeting a fragment of Leishmania hsp70 gene was performed employing DNA extracted from damaged skin. RFLP of the amplified hsp70 fragment identified the parasite as L. infantum, instead of Leishmania braziliensis, the main agent of cutaneous leishmaniasis in Rio de Janeiro. Characterization of isolated promastigotes by five different enzymatic systems confirmed the species identification of the etiological agent. Serology was positive by ELISA and rapid test. This case warns to the suspicion of viscerotropic Leishmania in cases of chronic skin lesions and brings the discussion of the mechanisms involved in the parasite tissue tropism. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Qualidade espermática de sêmen de cães naturalmente infectados por Leishmania sp: Semen quality of dogs naturally infected by Leishmania sp

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    É. Labat

    2010-06-01

    Full Text Available Avaliaram-se alterações espermáticas associadas à infecção por leishmaniose no sêmen de cães naturalmente infectados, utilizando-se, durante oito semanas consecutivas, ejaculados de seis cães soronegativos e seis cães soropositivos. As amostras foram colhidas uma vez por semana e avaliadas quanto ao volume, concentração, motilidade, vigor, morfologia espermática, integridade da cromatina, avaliação simultânea da integridade da membrana plasmática, acrossoma e potencial mitocondrial. Concomitantemente foram dosadas a proteína total do plasma seminal e sanguíneo. A leishmaniose visceral causou aumento dos defeitos maiores e menores nos espermatozoides dos animais acometidos pelo estágio moderado a severo da doença. Em estágios mais avançados da enfermidade, a integridade das membranas acrossomal e plasmática foi afetada negativamente. Não foi possível estabelecer um critério quanto à avaliação do potencial mitocondrial. A incidência de alterações morfológicas nos animais acometidos não promoveu aumento de injurias à cromatina. Todos os animais com leishmaniose apresentaram hiperproteinemia do sêmen.The spermatic changes associated with the natural infection in dogs by Leishmania sp was evaluated during eight consecutive weeks, using ejaculates of six seronegative and six seropositive dogs. The samples were collected once a week and evaluated for volume, concentration, motility, vigor, sperm morphology, chromatin integrity, simultaneous evaluation of the plasmatic membrane integrity, acrosome, and mitochondrial potential. The total proteins of the seminal plasma and blood were measured. The visceral leishmaniasis caused increase of major and minor defects in spermatozoa of animals attacked by moderate to severe stages of the disease. In more advanced stages of the illness, the acrosomal and plasmatic membranes integrity was adversely affected. It was not possible to establish a pattern refering the evaluation of

  7. Could Phlebotomus mascittii play a role as a natural vector for Leishmania infantum? New data.

    Science.gov (United States)

    Obwaller, Adelheid G; Karakus, Mehmet; Poeppl, Wolfgang; Töz, Seray; Özbel, Yusuf; Aspöck, Horst; Walochnik, Julia

    2016-08-19

    The occurrence of phlebotomine sand flies in Central Europe was questioned until they were recorded for the first time in Germany in 1999, and ten years later also in Austria. The aim of this study was to investigate sand flies collected in Austria for their carrier status of Leishmania spp. From 2012 to 2013 field studies were conducted in eastern Austria. Altogether, 22 individuals of sand flies were found, all morphologically identified as Phlebotomus (Transphlebotomus) mascittii Grassi, 1908. Twelve non-engorged female specimens with no visible remnants of a blood meal in their bodies were individually investigated for Leishmania spp. by ITS-1 real-time PCR. One out of these was positive for Leishmania, identified as Leishmania infantum by DNA sequencing. This finding suggests that L. infantum is not excreted by P. mascittii and possibly can establish an infection within P. mascittii. Interestingly, an asymptomatic dog living on the farm where this sand fly had been caught was also Leishmania-positive. This study provides new data on the suspected vector capacity of P. mascittii, being the northernmost sand fly species in Europe and in most central European regions the only sand fly species found. Proven vector capacity of P. mascittii for Leishmania spp. would be of significant medico-veterinary importance, not only with respect to expanding sand fly populations in Central Europe related to global warming, but also in the light of globalization and increasing movements of humans.

  8. Leishmania and its quest for iron: An update and overview.

    Science.gov (United States)

    Zaidi, Amir; Singh, Krishn Pratap; Ali, Vahab

    2017-01-01

    Parasites of genus Leishmania are the causative agents of complex neglected diseases called leishmaniasis and continue to be a significant health concern globally. Iron is a vital nutritional requirement for virtually all organisms, including pathogenic trypanosomatid parasites, and plays a crucial role in many facets of cellular metabolism as a cofactor of several enzymes. Iron acquisition is essential for the survival of parasites. Yet parasites are also vulnerable to the toxicity of iron and reactive oxygen species. The aim of this review is to provide an update on the current knowledge about iron acquisition and usage by Leishmania species. We have also discussed about host strategy to modulate iron availability and the strategies deployed by Leishmania parasites to overcome iron withholding defences and thus favour parasite growth within host macrophages. Since iron plays central roles in the host's response and parasite metabolism, a comprehensive understanding of the iron metabolism is beneficial to identify potential viable therapeutic opportunities against leishmaniasis. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Deception and Manipulation: The Arms of Leishmania, a Successful Parasite

    Science.gov (United States)

    Cecílio, Pedro; Pérez-Cabezas, Begoña; Santarém, Nuno; Maciel, Joana; Rodrigues, Vasco; Cordeiro da Silva, Anabela

    2014-01-01

    Leishmania spp. are intracellular parasitic protozoa responsible for a group of neglected tropical diseases, endemic in 98 countries around the world, called leishmaniasis. These parasites have a complex digenetic life cycle requiring a susceptible vertebrate host and a permissive insect vector, which allow their transmission. The clinical manifestations associated with leishmaniasis depend on complex interactions between the parasite and the host immune system. Consequently, leishmaniasis can be manifested as a self-healing cutaneous affliction or a visceral pathology, being the last one fatal in 85–90% of untreated cases. As a result of a long host–parasite co-evolutionary process, Leishmania spp. developed different immunomodulatory strategies that are essential for the establishment of infection. Only through deception and manipulation of the immune system, Leishmania spp. can complete its life cycle and survive. The understanding of the mechanisms associated with immune evasion and disease progression is essential for the development of novel therapies and vaccine approaches. Here, we revise how the parasite manipulates cell death and immune responses to survive and thrive in the shadow of the immune system. PMID:25368612

  10. Deception and Manipulation: the arms of Leishmania, a successful parasite

    Directory of Open Access Journals (Sweden)

    Pedro eCecílio

    2014-10-01

    Full Text Available Leishmania spp. are intracellular parasitic protozoa responsible for a group of neglected tropical diseases, endemic in 98 countries around the world, called leishmaniasis. These parasites have a complex digenetic life cycle requiring a susceptible vertebrate host and a permissive insect vector, which allow their transmission. The clinical manifestations associated with leishmaniasis depend on complex interactions between the parasite and the host immune system. Consequently, leishmaniasis can be manifested as a self-healing cutaneous affliction or a visceral pathology, being the last one fatal in 85-90% of untreated cases. As a result of a long host-parasite co-evolutionary process, Leishmania spp. developed different immunomodulatory strategies that are essential for the establishment of infection. Only through deception and manipulation of the immune system, Leishmania spp. can complete its life cycle and survive. The understanding of the mechanisms associated with immune evasion and disease progression is essential for the development of novel therapies and vaccine approaches. Here, we revise how the parasite manipulates cell death and immune responses to survive and thrive in the shadow of the immune system.

  11. Polymerase chain reaction-based method for the identification of Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in mucosal tissues conserved in paraffin.

    Science.gov (United States)

    Prestes, Suzane Ribeiro; Guerra, Jorge Augusto de Oliveira; Romero, Gustavo Adolfo Sierra; Magalhaes, Laylah Kelre Costa; Santana, Rosa Amelia Gonçalves; Maciel, Marcel Gonçalves; Custódio, Ana; Barbosa, Maria das Graças Vale; Silveira, Henrique

    2015-01-01

    In the Americas, mucosal leishmaniasis is primarily associated with infection by Leishmania (Viannia) braziliensis. However, Leishmania (Viannia) guyanensis is another important cause of this disease in the Brazilian Amazon. In this study, we aimed at detecting Leishmaniadeoxyribonucleic acid (DNA) within paraffin-embedded fragments of mucosal tissues, and characterizing the infecting parasite species. We evaluated samples collected from 114 patients treated at a reference center in the Brazilian Amazon by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses. Direct examination of biopsy imprints detected parasites in 10 of the 114 samples, while evaluation of hematoxylin and eosin-stained slides detected amastigotes in an additional 17 samples. Meanwhile, 31/114 samples (27.2%) were positive for Leishmania spp. kinetoplast deoxyribonucleic acid (kDNA) by PCR analysis. Of these, 17 (54.8%) yielded amplification of the mini-exon PCR target, thereby allowing for PCR-RFLP-based identification. Six of the samples were identified as L. (V.) braziliensis, while the remaining 11 were identified as L. (V.) guyanensis. The results of this study demonstrate the feasibility of applying molecular techniques for the diagnosis of human parasites within paraffin-embedded tissues. Moreover, our findings confirm that L. (V.) guyanensisis a relevant causative agent of mucosal leishmaniasis in the Brazilian Amazon.

  12. Leishmania (Viannia) braziliensis infection in wild small mammals in ecotourism area of Brazil.

    Science.gov (United States)

    Tonelli, Gabriel Barbosa; Tanure, Aline; Rego, Felipe Dutra; Carvalho, Gustavo Mayr de Lima; Stumpp, Rodolfo; Ássimos, Gabriela Ribeiro; Campos, Aldenise Martins; Lima, Ana Cristina Viana Mariano da Rocha; Gontijo, Célia Maria Ferreira; Paz, Gustavo Fontes; Andrade Filho, José Dilermando

    2017-01-01

    Leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (Diptera: Psychodidae). Despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. The Reserva Particular do Patrimônio Natural Santuário do Caraça (RPPNSC) is one of the largest ecotourism attractions in the State of Minas Gerais, Brazil, and comprises an area of environmental preservation with 11,233 hectares presenting a transitional vegetation between Cerrado and Atlantic Forest. The present study describes the abundance of small mammals in RPPNSC, the isolation and identification of Leishmania in five wild animals. Small mammals were bimonthly trapped along 6 trails within the RPPNSC with 10 Tomahawk traps each. Two trails were located in peridomiciliary areas near tourist lodging facilities, and four trails were located at sites visited by tourists in forest areas. The most prevalent species were Akodon cursor, Cerradomys subflavus and Oligoryzomys nigripes. Six isolates of Leishmania were obtained from these animals and identified as Leishmania braziliensis through HSP70-PCR RFLP method. Leishmania spp. DNA was detected by kDNA-PCR method and isolated by biphasic culture. Studies point to some of the captured species as potential wild reservoirs of Leishmania, suggesting they may be involved in the transmission cycle in these wild environments.

  13. Microbial stasis of Leishmania enriettii in activated guinea pig macrophages

    International Nuclear Information System (INIS)

    Groocock, C.M.; Soulsby, E.J.L.

    1980-01-01

    Peritoneal exudate cells (PEC) from Leishmania-sensitized guinea pigs were cultured in vitro in the presence (activated) or absence (non-activated) of leishmanial antigen for 24 or 48 hours. These were then labelled with 51 Cr and challenged with 125 I-labelled promastigotes. The changing relationship between the macrophage and the parasite was monitored by observing changes in the ratio of the cell-associated isotopes. Highly significant differences in the ratio change developed during culture. These differences were a result of the activated cultures showing a higher release of 51 Cr and a lower release of 125 I when compared with the non-activated cells, at 12 hours the percentage release of 125 I from the parasite within the activated macrophage was fourfold less than that released by parasites within non-activated cells (9.2% versus 38.3%) and tenfold less than that released from glutaraldehyde-killed organisms phagocytosed by activated macrophages (91.6%). These studies indicate that stasis rather than killing of leishmaniae occurs in the activated macrophage in vitro. Parallel experiments evaluated by the visual counting of leishmaniae within the macrophages support these data. PEC from tuberculin-sensitized guinea pigs activated in vitro by purified protein derivative showed little or no activity against leishmaniae, indicating a specific requirement for this microbial stasis by activated macrophages. As a corollary of this, peritoneal exudate lymphocytes separated from the same preparations of PEC were shown to be specifically reactive to leishmanial antigen by transformation and incorporation of 3 H-thymidine. (author)

  14. Changes to cholesterol trafficking in macrophages by Leishmania parasites infection.

    Science.gov (United States)

    Semini, Geo; Paape, Daniel; Paterou, Athina; Schroeder, Juliane; Barrios-Llerena, Martin; Aebischer, Toni

    2017-08-01

    Leishmania spp. are protozoan parasites that are transmitted by sandfly vectors during blood sucking to vertebrate hosts and cause a spectrum of diseases called leishmaniases. It has been demonstrated that host cholesterol plays an important role during Leishmania infection. Nevertheless, little is known about the intracellular distribution of this lipid early after internalization of the parasite. Here, pulse-chase experiments with radiolabeled cholesteryl esterified to fatty acids bound to low-density lipoproteins indicated that retention of this source of cholesterol is increased in parasite-containing subcellular fractions, while uptake is unaffected. This is correlated with a reduction or absence of detectable NPC1 (Niemann-Pick disease, type C1), a protein responsible for cholesterol efflux from endocytic compartments, in the Leishmania mexicana habitat and infected cells. Filipin staining revealed a halo around parasites within parasitophorous vacuoles (PV) likely representing free cholesterol accumulation. Labeling of host cell membranous cholesterol by fluorescent cholesterol species before infection revealed that this pool is also trafficked to the PV but becomes incorporated into the parasites' membranes and seems not to contribute to the halo detected by filipin. This cholesterol sequestration happened early after infection and was functionally significant as it correlated with the upregulation of mRNA-encoding proteins required for cholesterol biosynthesis. Thus, sequestration of cholesterol by Leishmania amastigotes early after infection provides a basis to understand perturbation of cholesterol-dependent processes in macrophages that were shown previously by others to be necessary for their proper function in innate and adaptive immune responses. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  15. Liposomal Formulation of Turmerone-Rich Hexane Fractions from Curcuma longa Enhances Their Antileishmanial Activity

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    Ana Claudia F. Amaral

    2014-01-01

    Full Text Available Promastigote forms of Leishmania amazonensis were treated with different concentrations of two fractions of Curcuma longa cortex rich in turmerones and their respective liposomal formulations in order to evaluate growth inhibition and the minimal inhibitory concentration (MIC. In addition, cellular alterations of treated promastigotes were investigated under transmission and scanning electron microscopies. LipoRHIC and LipoRHIWC presented lower MIC, 5.5 and 12.5 μg/mL, when compared to nonencapsulated fractions (125 and 250 μg/mL, respectively, and to ar-turmerone (50 μg/mL. Parasite growth inhibition was demonstrated to be dose-dependent. Important morphological changes as rounded body and presence of several roles on plasmatic membrane could be seen on L. amazonensis promastigotes after treatment with subinhibitory concentration (2.75 μg/mL of the most active LipoRHIC. In that sense, the hexane fraction from the turmeric cortex of Curcuma longa incorporated in liposomal formulation (LipoRHIC could represent good strategy for the development of new antileishmanial agent.

  16. Liposomal Formulation of Turmerone-Rich Hexane Fractions from Curcuma longa Enhances Their Antileishmanial Activity

    Science.gov (United States)

    Amaral, Ana Claudia F.; Gomes, Luciana A.; Silva, Jefferson Rocha de A.; Ferreira, José Luiz P.; Ramos, Aline de S.; Rosa, Maria do Socorro S.; Vermelho, Alane B.; Rodrigues, Igor A.

    2014-01-01

    Promastigote forms of Leishmania amazonensis were treated with different concentrations of two fractions of Curcuma longa cortex rich in turmerones and their respective liposomal formulations in order to evaluate growth inhibition and the minimal inhibitory concentration (MIC). In addition, cellular alterations of treated promastigotes were investigated under transmission and scanning electron microscopies. LipoRHIC and LipoRHIWC presented lower MIC, 5.5 and 12.5 μg/mL, when compared to nonencapsulated fractions (125 and 250 μg/mL), respectively, and to ar-turmerone (50 μg/mL). Parasite growth inhibition was demonstrated to be dose-dependent. Important morphological changes as rounded body and presence of several roles on plasmatic membrane could be seen on L. amazonensis promastigotes after treatment with subinhibitory concentration (2.75 μg/mL) of the most active LipoRHIC. In that sense, the hexane fraction from the turmeric cortex of Curcuma longa incorporated in liposomal formulation (LipoRHIC) could represent good strategy for the development of new antileishmanial agent. PMID:25045693

  17. Amplified DNAs in laboratory stocks of Leishmania tarentolae: extrachromosomal circles structurally and functionally similar to the inverted-H-region amplification of methotrexate-resistant Leishmania major

    International Nuclear Information System (INIS)

    Petrillo-Peixoto, M.L.; Beverley, S.M.

    1988-01-01

    We describe the structure of amplified DNA that was discovered in two laboratory stocks of the protozoan parasite Leishmania tarentolae. Restriction mapping and molecular cloning revealed that a region of 42 kilobases was amplified 8- to 30-fold in these lines. Southern blot analyses of digested DNAs or chromosomes separated by pulsed-field electrophoresis showed that the amplified DNA corresponded to the H region, a locus defined originally by its amplification in methotrexate-resistant Leishmania major. Similarities between the amplified DNA of the two species included (i) extensive cross-hybridization; (ii) approximate conservation of sequence order; (iii) extrachromosomal localization; (iv) an overall inverted, head-to-head configuration as a circular 140-kilobase tetrameric molecule; (v) two regions of DNA sequence rearrangement, each of which was closely associated with the two centers of the inverted repeats; (vi) association with methotrexate resistance; and (vii) phenotypically conservative amplification, in which the wild-type chromosomal arrangement was retained without apparent modification. Our data showed that amplified DNA mediating drug resistance arose in unselected L. tarentolae, although the pressures leading to apparently spontaneous amplification and maintenance of the H region are not known. The simple structure and limited extent of DNA amplified in these and other Leishmania lines suggests that the study of gene amplification in Leishmania spp. offers an attractive model system for the study of amplification in cultured mammalian cells and tumors. We also introduced a method for measuring the size of large circular DNAs, using gamma-irradiation to introduce limited double-strand breaks followed by sizing of the linear DNAs by pulsed-field electrophoresis

  18. Optimization of loop-mediated isothermal amplification (LAMP) assays for the detection of Leishmania DNA in human blood samples.

    Science.gov (United States)

    Abbasi, Ibrahim; Kirstein, Oscar D; Hailu, Asrat; Warburg, Alon

    2016-10-01

    Visceral leishmaniasis (VL), one of the most important neglected tropical diseases, is caused by Leishmania donovani eukaryotic protozoan parasite of the genus Leishmania, the disease is prevalent mainly in the Indian sub-continent, East Africa and Brazil. VL can be diagnosed by PCR amplifying ITS1 and/or kDNA genes. The current study involved the optimization of Loop-mediated isothermal amplification (LAMP) for the detection of Leishmania DNA in human blood or tissue samples. Three LAMP systems were developed; in two of those the primers were designed based on shared regions of the ITS1 gene among different Leishmania species, while the primers for the third LAMP system were derived from a newly identified repeated region in the Leishmania genome. The LAMP tests were shown to be sufficiently sensitive to detect 0.1pg of DNA from most Leishmania species. The green nucleic acid stain SYTO16, was used here for the first time to allow real-time monitoring of LAMP amplification. The advantage of real time-LAMP using SYTO 16 over end-point LAMP product detection is discussed. The efficacy of the real time-LAMP tests for detecting Leishmania DNA in dried blood samples from volunteers living in endemic areas, was compared with that of qRT-kDNA PCR. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives

    Directory of Open Access Journals (Sweden)

    Asunción Burguete

    2008-12-01

    Full Text Available A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E-3-(3,4,5-trimethoxy-phenyl-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.

  20. Chemodiversity Associated with Cytotoxicity and Antimicrobial Activity of Piper aduncum var. ossanum.

    Science.gov (United States)

    Gutiérrez, Yamilet; Montes, Rodny; Scull, Ramón; Sánchez, Arturo; Cos, Paul; Monzote, Lianet; Setzer, William N

    2016-12-01

    Chemical analysis, antimicrobial activity and cytotoxic effects of essential oils (EOs) from leaves of Piper aduncum var. ossanum from two localities Bauta (EO-B) and Ceiba (EO-C), Artemisa Province, Cuba, were determined. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. EO-B demonstrated higher activity against S. aureus and L. amazonensis; while a lower cytotoxicity on mammalian cells was observed. Both EOs displayed the same activity against Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei, and Leishmania infantum. Both EOs were inactive against Escherichia coli and Candida albicans. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  1. Estudios de secreción de IL-12 en macrófagos J774A.1

    OpenAIRE

    Rojas Rojas, Angela Patricia

    2012-01-01

    El tráfico de membranas en macrófagos activados es requerido para dos eventos críticos en la inmunidad innata, como son fagocitosis y secreción de citoquinas proinflamatorias. Sin embargo, no existe evidencia significativa a cerca de las rutas de secreción en macrófagos, excepto para IL-1 β (Andrei et al., 2004) y TNF-a, en infección por Cándida albicans (Murray et al., 2005) y Leishmania amazonensis (Montoya, 2010), a diferencia de la secreción en células endocrinas y neuroendocrinas d...

  2. A Novel Molecular Test to Diagnose Canine Visceral Leishmaniasis at the Point of Care

    Science.gov (United States)

    Castellanos-Gonzalez, Alejandro; Saldarriaga, Omar A.; Tartaglino, Lilian; Gacek, Rosana; Temple, Elissa; Sparks, Hayley; Melby, Peter C.; Travi, Bruno L.

    2015-01-01

    Dogs are the principal reservoir hosts of zoonotic visceral leishmaniasis (VL) but current serological methods are not sensitive enough to detect all subclinically infected animals, which is crucial to VL control programs. Polymerase chain reaction (PCR) methods have greater sensitivity but require expensive equipment and trained personnel, impairing its implementation in endemic areas. We developed a diagnostic test that uses isothermal recombinase polymerase amplification (RPA) to detect Leishmania infantum. This method was coupled with lateral flow (LF) reading with the naked eye to be adapted as a point-of-care test. The L. infantum RPA-LF had an analytical sensitivity similar to real time-PCR, detecting DNA of 0.1 parasites spiked in dog blood, which was equivalent to 40 parasites/mL. There was no cross amplification with dog or human DNA or with Leishmania braziliensis, Leishmania amazonensis, or Trypanosoma cruzi. The test also amplified Leishmania donovani strains (N = 7). In a group of clinically normal dogs (N = 30), RPA-LF detected more subclinical infections than rK39 strip test, a standard serological method (50% versus 13.3% positivity, respectively; P = 0.005). Also, RPA-LF detected L. infantum in noninvasive mucosal samples of dogs with a sensitivity comparable to blood samples. This novel molecular test may have a positive impact in leishmaniasis control programs. PMID:26240156

  3. Aspectos epidemiológicos, clínicos e laboratoriais da leishmaniose visceral em cães (Canis familiaris) (Linnaeus, 1758) provenientes da zona urbana do município de Bom Jesus- PI e região metropolitana do Recife- PE, Brasil.

    OpenAIRE

    Jamile Prado dos Santos

    2010-01-01

    A Leishmaniose Visceral Canina (LVC) no Brasil é causada por Leishmania infantum a qual é relatada em várias regiões. O objetivo desta pesquisafoi verificar aspectos epidemiológicos, clínicos e laboratoriais da leishmaniose visceral em cães (Canis familiaris) (Linnaeus, 1758) provenientes da zona urbana do município de Bom Jesus PI e Região Metropolitana de Recife - PE, Brasil. Cães do município de Bom Jesus, Piauí, e do bairro de Muribeca, município de Jaboatão dos Guararapes, Pernambuco...

  4. Mitochondrial Proteomics of Antimony and Miltefosine Resistant Leishmania infantum

    Directory of Open Access Journals (Sweden)

    Isabel M. Vincent

    2015-10-01

    Full Text Available Antimony (SbIII and miltefosine (MIL are important drugs for the treatment of Leishmania parasite infections. The mitochondrion is likely to play a central role in SbIII and MIL induced cell death in this parasite. Enriched mitochondrial samples from Leishmania promastigotes selected step by step for in vitro resistance to SbIII and MIL were subjected to differential proteomic analysis. A shared decrease in both mutants in the levels of pyruvate dehydrogenase, dihydrolipoamide dehydrogenase, and isocitrate dehydrogenase was observed, as well as a differential abundance in two calcium-binding proteins and the unique dynamin-1-like protein of the parasite. Both mutants presented a shared increase in the succinyl-CoA:3-ketoacid-coenzyme A transferase and the abundance of numerous hypothetical proteins was also altered in both mutants. In general, the proteomic changes observed in the MIL mutant were less pronounced than in the SbIII mutant, probably due to the early appearance of a mutation in the miltefosine transporter abrogating the need for a strong mitochondrial adaptation. This study is the first analysis of the Leishmania mitochondrial proteome and offers powerful insights into the adaptations to this organelle during SbIII and MIL drug resistance.

  5. Fitness of Leishmania donovani parasites resistant to drug combinations.

    Directory of Open Access Journals (Sweden)

    Raquel García-Hernández

    2015-04-01

    Full Text Available Drug resistance represents one of the main problems for the use of chemotherapy to treat leishmaniasis. Additionally, it could provide some advantages to Leishmania parasites, such as a higher capacity to survive in stress conditions. In this work, in mixed populations of Leishmania donovani parasites, we have analyzed whether experimentally resistant lines to one or two combined anti-leishmanial drugs better support the stress conditions than a susceptible line expressing luciferase (Luc line. In the absence of stress, none of the Leishmania lines showed growth advantage relative to the other when mixed at a 1:1 parasite ratio. However, when promastigotes from resistant lines and the Luc line were mixed and exposed to different stresses, we observed that the resistant lines are more tolerant of different stress conditions: nutrient starvation and heat shock-pH stress. Further to this, we observed that intracellular amastigotes from resistant lines present a higher capacity to survive inside the macrophages than those of the control line. These results suggest that resistant parasites acquire an overall fitness increase and that resistance to drug combinations presents significant differences in their fitness capacity versus single-drug resistant parasites, particularly in intracellular amastigotes. These results contribute to the assessment of the possible impact of drug resistance on leishmaniasis control programs.

  6. Evaluating the Role of Host AMPK in Leishmania Burden.

    Science.gov (United States)

    Moreira, Diana; Estaquier, Jérôme; Cordeiro-da-Silva, Anabela; Silvestre, Ricardo

    2018-01-01

    The study of host AMP-activated protein kinase (AMPK) activation during Leishmania infection imposes distinct types of techniques to measure protein expression and activation, as well as to quantify, at transcription and translational levels, its downstream targets. The investigation of host AMPK protein modulation during Leishmania infection should primarily be assessed during in vitro infections using as a host murine bone marrow-derived macrophages (BMMos). The infection outcome is assessed measuring the percentage of infected cells in the context of BMMos. To evaluate AMPK activity during infection, the expression of AMPK phosphorylated at Thr172 as well as the transcription and translational levels of its downstream targets are evaluated by quantitative PCR and immunoblotting. The modulation of AMPK activity in vivo is determined specifically in sorted splenic macrophages harboring Leishmania parasites recovered from infected mice using fluorescent-labeled parasites in the infectious inocolum. The modulation of AMPK activity was assessed by AMPK activators and inhibitors and also using AMPK, SIRT1, or LKB1 KO mice models. The infection outcome in BMMos and in vivo was further determined using these two different approaches. To finally understand the metabolic impact of AMPK during infection, in vitro metabolic assays in infected BMMos were measured in the bioenergetic profile using an extracellular flux analyzer.

  7. Histochemical and molecular evaluation of the prevalence of Leishmania spp. in hematophagous insects

    Directory of Open Access Journals (Sweden)

    Willian Marinho Dourado Coelho

    2016-06-01

    Full Text Available The prevalence study of Leishmania spp. in hematophagous insects captured from the environment in bat roosts and pigeon nests, or feeding their hosts (cattle, pigs, horses, dogs and humans in urban, peri-urban and rural areas, between 2012 and 2014. For this study, the amastigotes present in these insects were detected by histochemical and PCR techniques. Positive gene amplification for Leishmania was found in two horseflies of the species Tabanus importunus collected in the environment, and amastigote forms of Leishmania spp., as well as erythrocytes and leukocytes, were histochemically detected in one of that insect. The other analyzed insects were not positive by PCR our by direct parasitological examination. Only horseflies captured in urban and peri-urban areas were positive. During the collection, no phlebotomine sand flies were captured in rural areas far from the city limits. It can be concluded that the discovery of horseflies positive for Leishmania spp. in urban and peri-urban areas indicates the likelihood that urban areas and their surroundings provide vector parasites with an environment suitable for the spread and consequent perpetuation of the biological cycle of this protozoan.

  8. Functional transcriptomics of wild-caught Lutzomyia intermedia salivary glands: identification of a protective salivary protein against Leishmania braziliensis infection.

    Science.gov (United States)

    de Moura, Tatiana R; Oliveira, Fabiano; Carneiro, Marcia W; Miranda, José Carlos; Clarêncio, Jorge; Barral-Netto, Manoel; Brodskyn, Cláudia; Barral, Aldina; Ribeiro, José M C; Valenzuela, Jesus G; de Oliveira, Camila I

    2013-01-01

    Leishmania parasites are transmitted in the presence of sand fly saliva. Together with the parasite, the sand fly injects salivary components that change the environment at the feeding site. Mice immunized with Phlebotomus papatasi salivary gland (SG) homogenate are protected against Leishmania major infection, while immunity to Lutzomyia intermedia SG homogenate exacerbated experimental Leishmania braziliensis infection. In humans, antibodies to Lu. intermedia saliva are associated with risk of acquiring L. braziliensis infection. Despite these important findings, there is no information regarding the repertoire of Lu. intermedia salivary proteins. A cDNA library from the Salivary Glands (SGs) of wild-caught Lu. intermedia was constructed, sequenced, and complemented by a proteomic approach based on 1D SDS PAGE and mass/mass spectrometry to validate the transcripts present in this cDNA library. We identified the most abundant transcripts and proteins reported in other sand fly species as well as novel proteins such as neurotoxin-like proteins, peptides with ML domain, and three small peptides found so far only in this sand fly species. DNA plasmids coding for ten selected transcripts were constructed and used to immunize BALB/c mice to study their immunogenicity. Plasmid Linb-11--coding for a 4.5-kDa protein--induced a cellular immune response and conferred protection against L. braziliensis infection. This protection correlated with a decreased parasite load and an increased frequency of IFN-γ-producing cells. We identified the most abundant and novel proteins present in the SGs of Lu. intermedia, a vector of cutaneous leishmaniasis in the Americas. We also show for the first time that immunity to a single salivary protein from Lu. intermedia can protect against cutaneous leishmaniasis caused by L. braziliensis.

  9. Natural infection of Lutzomyia tortura with Leishmania (Viannia) naiffi in an Amazonian area of Ecuador.

    Science.gov (United States)

    Kato, Hirotomo; Gomez, Eduardo A; Yamamoto, Yu-ichi; Calvopiña, Manuel; Guevara, Angel G; Marco, Jorge D; Barroso, Paola A; Iwata, Hiroyuki; Hashiguchi, Yoshihisa

    2008-09-01

    Natural infection of sand flies with Leishmania parasites was surveyed in an Amazonian area in Ecuador where leishmaniasis is endemic. Seventy-one female sand flies were dissected and one was positive for Leishmania protozoa. The species of this sand fly was identified as Lutzomyia (Lu.) tortura on the basis of morphologic characteristics. Analysis of the cytochrome b gene sequence identified the parasite as L. (Viannia) naiffi. We report the distribution of L. (V.) naiffi in Ecuador and detection of a naturally infected sand fly in the Ecuadorian Amazon and natural infection of Lu. tortura with Leishmania parasites in the New World.

  10. Identification of Leishmania tropica from micro-foci of cutaneous leishmaniasis in the Kenyan Rift Valley.

    Science.gov (United States)

    Odiwuor, Samwel; Muia, Alfred; Magiri, Charles; Maes, Ilse; Kirigi, George; Dujardin, Jean-Claude; Wasunna, Monique; Mbuchi, Margaret; Auwera, Gert Van der

    2012-07-01

    We performed diagnosis and species identification of parasites in lesion samples from suspected cutaneous leishmaniasis patients in four villages, three of which are in a known Leishmania tropica endemic region in Kenya. Samples were analyzed both by microscopy and PCR for Leishmania, and typed by an assay using four ribosomal DNA-based species-identification PCRs. The lesions were demonstrated to be caused by L. tropica, which confirms the re-emergence of cutaneous leishmaniasis from this species after a period of reduced incidence in the endemic zone. Our report highlights the importance of an intervention and sustained Leishmania control program.

  11. Licochalcone A, a novel antiparasitic agent with potent activity against human pathogenic protozoan species of Leishmania

    DEFF Research Database (Denmark)

    Chen, M; Christensen, S B; Blom, J

    1993-01-01

    Licochalcone A, an oxygenated chalcone isolated from the roots of Chinese licorice plant, inhibited the growth of both Leishmania major and Leishmania donovani promastigotes and amastigotes. The structure of the licochalcone A was established by mass and nuclear magnetic resonance spectroscopies...... killing of the parasite. These data show that intracellular Leishmania amastigotes are more susceptible than promastigotes to licochalcone A. Results of studies on the site of action of licochalcone A indicate that the target organelle appears to be the parasite mitochondria. These findings demonstrate...

  12. Spatial distribution, Leishmania species and clinical traits of Cutaneous Leishmaniasis cases in the Colombian army.

    Science.gov (United States)

    Patino, Luz H; Mendez, Claudia; Rodriguez, Omaira; Romero, Yanira; Velandia, Daniel; Alvarado, Maria; Pérez, Julie; Duque, Maria Clara; Ramírez, Juan David

    2017-08-01

    In Colombia, the cutaneous leishmaniasis (CL) is the most common manifestation across the army personnel. Hence, it is mandatory to determine the species associated with the disease as well as the association with the clinical traits. A total of 273 samples of male patients with CL were included in the study and clinical data of the patients was studied. PCR and sequencing analyses (Cytb and HSP70 genes) were performed to identify the species and the intra-specific genetic variability. A georeferenced database was constructed to identify the spatial distribution of Leishmania species isolated. The identification of five species of Leishmania that circulate in the areas where army personnel are deployed is described. Predominant infecting Leishmania species corresponds to L. braziliensis (61.1%), followed by Leishmania panamensis (33.5%), with a high distribution of both species at geographical and municipal level. The species L. guyanensis, L. mexicana and L. lainsoni were also detected at lower frequency. We also showed the identification of different genotypes within L. braziliensis and L. panamensis. In conclusion, we identified the Leishmania species circulating in the areas where Colombian army personnel are deployed, as well as the high intra-specific genetic variability of L. braziliensis and L. panamensis and how these genotypes are distributed at the geographic level.

  13. Post-Genomics and Vaccine Improvement for Leishmania

    Science.gov (United States)

    Seyed, Negar; Taheri, Tahereh; Rafati, Sima

    2016-01-01

    Leishmaniasis is a parasitic disease that primarily affects Asia, Africa, South America, and the Mediterranean basin. Despite extensive efforts to develop an effective prophylactic vaccine, no promising vaccine is available yet. However, recent advancements in computational vaccinology on the one hand and genome sequencing approaches on the other have generated new hopes in vaccine development. Computational genome mining for new vaccine candidates is known as reverse vaccinology and is believed to further extend the current list of Leishmania vaccine candidates. Reverse vaccinology can also reduce the intrinsic risks associated with live attenuated vaccines. Individual epitopes arranged in tandem as polytopes are also a possible outcome of reverse genome mining. Here, we will briefly compare reverse vaccinology with conventional vaccinology in respect to Leishmania vaccine, and we will discuss how it influences the aforementioned topics. We will also introduce new in vivo models that will bridge the gap between human and laboratory animal models in future studies. PMID:27092123

  14. Prevalence of Leishmania species in rodents: A systematic review and meta-analysis in Iran.

    Science.gov (United States)

    Foroutan, Masoud; Khademvatan, Shahram; Majidiani, Hamidreza; Khalkhali, Hamidreza; Hedayati-Rad, Faezeh; Khashaveh, Shahla; Mohammadzadeh, Habib

    2017-08-01

    Leishmaniasis are diverse group of diseases caused by numerous species of genus Leishmania. Herein we have contrived a systematic review and meta-analysis on the prevalence of Leishmania species in rodents of Iran. For this purpose, following the general methodology recommended for systematic reviews and meta-analysis, six English databases (PubMed, Science Direct, Scopus, Ovid, Web of Science and Google Scholar) and four Persian databases (Magiran, SID, Iran Doc and Iran Medex) were explored during January 1995 till June 2015. Papers were selected based on 8 pre-defined inclusion criteria. During the years, a total number of 4485 different rodents were captured; among which 1291 cases were Leishmania positive. The calculated weighted prevalence of Leishmania species in rodents was 23% (95% CI=18-28). Given geographical zones of Iran, the highest and lowest prevalence rate was belonged to North 50% (95% CI=40-61) and West 11% (95% CI=5-17), respectively. Rhombomys opimus (1766), Meriones lybicus (1258) and Tatera indica (488) were the three most abundant captured rodents, while the highest prevalence of Leishmania species was observed in Nesokia indica 48% (95% CI=42-54) and followed by R. opimus 39% (95% CI=30-47). Egger's regression test was performed to detect publication bias, which revealed it may not have a significant influence on overall weighted prevalence estimate (P=0.317). Meta-regression analysis demonstrated that there is no significant relationship between overall prevalence with sample size (P=0.1) and year of publication (P=0.7). The results showed remarkable prevalence of Leishmania species in rodent reservoirs. In future, adopting a suitable strategy for control and combat with rodents is necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Adenine phosphoribosyltransferase-deficient Leishmania donovani

    International Nuclear Information System (INIS)

    Kaur, K.; Iovannisci, D.M.; Ullman, B.

    1986-01-01

    To elucidate the relative roles of two routes for adenine salvage, the authors use biochemical genetic approaches to isolate clonal strains of Leishmania donovani promasatigotes genetically deficient in APRTase activity. The studies suggest that the metabolic rate of adenine in these organisms is initiated by deamination. The radiolabel incorporation experiments and biochemical experiments are described in which the rate of uptake of radiolabelled purine nucleobases (C 14) was determined. Results are presented

  16. Role of calmodulin and calcineurin in regulating flagellar motility and wave polarity in Leishmania.

    Science.gov (United States)

    Mukhopadhyay, Aakash Gautam; Dey, Chinmoy Sankar

    2017-11-01

    We have previously reported the involvement of cyclic AMP in regulating flagellar waveforms in Leishmania. Here, we investigated the roles of calcium, calmodulin, and calcineurin in flagellar motility regulation in L. donovani. Using high-speed videomicroscopy, we show that calcium-independent calmodulin and calcineurin activity is necessary for motility in Leishmania. Inhibition of calmodulin and calcineurin induced ciliary beats interrupting flagellar beating in both live (in vivo) and ATP-reactivated (in vitro) parasites. Our results indicate that signaling mediated by calmodulin and calcineurin operates antagonistically to cAMP signaling in regulating the waveforms of Leishmania flagellum. These two pathways are possibly involved in maintaining the balance between the two waveforms, essential for responding to environmental cues, survival, and infectivity.

  17. Leishmania diagnostic and identification py using 32P labelled DNA probes

    International Nuclear Information System (INIS)

    Andrade, Antero Silva Ribeiro de; Melo, Maria Norma de

    1999-10-01

    P 32 labelled DNA probes are valious instruments for the parasitic diseases by using hybridization reaction. In this paper we describe the methodology and present the foundations for the radioactive probes production, based on the kinetoplast DNA (kDNA), for the Leishmania diagnostic an identification. We also describe the kDNA purification protocol from Leishmania reference cepa, the process of P 32 labelling of the kDNA by using the nick translation method, gathering, sample preparation and treatment, the optimum conditions for the hybridization reaction and the procedures for the autoradiography

  18. Phenotypic and genotypic variations among three allopatric populations of Lutzomyia umbratilis, main vector of Leishmania guyanensis.

    Science.gov (United States)

    de Souza Freitas, Moises Thiago; Ríos-Velasquez, Claudia Maria; Costa, César Raimundo Lima; Figueirêdo, Carlos Alberto Santiago; Aragão, Nádia Consuelo; da Silva, Lidiane Gomes; de Aragão Batista, Marcus Vinicius; Balbino, Teresa Cristina Leal; Pessoa, Felipe Arley Costa; de Queiroz Balbino, Valdir

    2015-09-04

    In South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis, one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and in the state of Pernambuco, Northeastern region, where an isolated population has been identified. This study assessed the phylogeographic structure and size and shape differences of the wing of three Brazilian populations. Samples of L. umbratilis were collected from Rio Preto da Eva (north of the Amazon River, Amazonas), from Manacapuru (south of the Amazon River), and from the isolated population in Recife, Pernambuco state. These samples were processed to obtain sequences of the Cytochrome Oxidase I mitochondrial gene. Geometrics morphometry analysis of the right wing shape of the three populations was made using discriminate canonical analysis. Phylogenetic analysis revealed the presence of two distinct monophyletic clades: one clade comprised of the Recife and Rio Preto da Eva samples, and the other clade comprised of the Manacapuru samples. Comparing the Manacapuru population with the Recife and Rio Preto da Eva populations generated high indices of interpopulational divergence. Geometric morphometry analysis indicated two distinct groups between the studied populations. Canonical variate analysis of wing shape indicated that Rio Preto da Eva population is significantly closer to Recife population, and both populations were genetically distant from Manacapuru. The polymorphic sites and geometric morphometry analysis indicate that the distance, lack of continuity and environmental differences have not modified the ancestral relationship between Recife and Rio Preto da Eva populations. The genetic and morphological similarities shared by the Recife and Rio Preto da Eva populations suggest that these populations are more closely related evolutionarily. These results confirm the existence of an L. umbratilis species complex in

  19. Thrichomys laurentius (Rodentia; Echimyidae as a putative reservoir of Leishmania infantum and L. braziliensis: patterns of experimental infection.

    Directory of Open Access Journals (Sweden)

    André Luiz Rodrigues Roque

    Full Text Available The importance of the genus Thrichomys in the retention of infection and transmission of Leishmania species is supported by previous studies that describe an ancient interaction between caviomorphs and trypanosomatids and report the natural infection of Thrichomys spp. Moreover, these rodents are widely dispersed in Brazil and recognized as important hosts of other tripanosomatids. Our main purpose was to evaluate the putative role of Thrichomys laurentius in the retention of infection and amplification of the transmission cycle of Leishmania infantum and L. braziliensis. Male and female T. laurentius (n = 24 born in captivity were evaluated for the retention of infection with these Leishmania species and followed up by parasitological, serological, hematological, biochemical, histological, and molecular assays for 3, 6, 9, or 12 months post infection (mpi. T. laurentius showed its competence as maintenance host for the two inoculated Leishmania species. Four aspects should be highlighted: (i re-isolation of parasites 12 mpi; (ii the low parasitic burden displayed by T. laurentius tissues; (iii the early onset and maintenance of humoral response, and (iv the similar pattern of infection by the two Leishmania species. Both Leishmania species demonstrated the ability to invade and maintain itself in viscera and skin of T. laurentius, and no rodent displayed any lesion, histological changes, or clinical evidence of infection. We also wish to point out the irrelevance of the adjective dermotropic or viscerotropic to qualify L. braziliensis and L. infantum, respectively, when these species are hosted by nonhuman hosts. Our data suggest that T. laurentius may act at least as a maintenance host of both tested Leishmania species since it maintained long-lasting infections. Moreover, it cannot be discarded that Leishmania spp. infection in free-ranging T. laurentius could result in higher parasite burden due the more stressing conditions in the wild

  20. Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?

    Directory of Open Access Journals (Sweden)

    Felipe da Silva Krawczak

    2015-02-01

    Full Text Available INTRODUCTION: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites. METHODS: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT and by anti-Leishmania immunoglobulin G (IgG antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP (Bio Manguinhos(r/FIOCRUZ/MS and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios. RESULTS : Of 96 serum samples submitted to serological assays, 4 (4.2% were positive for Leishmania as determined by ELISA; 12 (12.5%, by IFAT; 14 (14.6% by rK39 RDT; and 20 (20.8%, by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9% and 30/96 (31.2% samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05. CONCLUSIONS: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil; we also found that the serological tests that were used did not cross-react.

  1. Leishmaniose Visceral Americana: (Relatorio dos trabalhos realisados pela commissão encarregada do estudo da Leishmaniose Visceral Americana em 1937

    Directory of Open Access Journals (Sweden)

    E. Chagas

    1938-01-01

    Full Text Available A Leishmania chagasi localisa-se principalmente nas cellulas reticulo-endotheliaaes dos tecidos. No sangue peripherico, o protozoario é visto com maior facilidade nos periodos iniciaes da infecção, quando pode ser observado livre, mais frequentemente no plasma de polynucleares e raramente no interior de macrophagos. Nas phases ulteriores, o parasito é raro no sangue peripherico e, quando encontrado, acha-se localisado no plasma de cellulas mononucleares. No interior dos leucocytos polynucleares apresentam as leishmanias signaes evidentes de degeneração, emquanto que nos macrophagos manteem o aspecto morphologico normal e as formas de multiplicação ocorrem com frequencia. Nos periodos agudos predominam os aspectos histo-pathologicos que traduzem intensa actividade do systema reticulo-endothelial e, nos periodos chronicos, a proliferação do tecido intesticial. O quadro hematologico é o de uma anemia sem signaes periphericos de regeneração. Os orgãos hematopoieticos demonstram signaes de perturbação funccional traduzida pelo exaggero da actividade que, entretanto, não leva á elaboração completa de globulos vermelhos, e á formação de granulocytos em número sufficiente. O quadro evolutivo da doença é o de uma anemia progressiva accompanhada de cachexia.

  2. Prostaglandin E2/leukotriene B4 balance induced by Lutzomyia longipalpis saliva favors Leishmania infantum infection.

    Science.gov (United States)

    Araújo-Santos, Théo; Prates, Deboraci Brito; França-Costa, Jaqueline; Luz, Nívea F; Andrade, Bruno B; Miranda, José Carlos; Brodskyn, Claudia I; Barral, Aldina; Bozza, Patrícia T; Borges, Valéria Matos

    2014-12-20

    Eicosanoids and sand fly saliva have a critical role in the Leishmania infection. Here, we evaluated the effect of Lutzomyia longipalpis salivary gland sonicate (SGS) on neutrophil and monocyte recruitment and activation of eicosanoid production in a murine model of inflammation. C57BL/6 mice were inoculated intraperitonealy with Lutzomyia longipalpis SGS or Leishmania infantum or both, followed by analyses of cell recruitment, parasite load and eicosanoid production. Intraperitoneal injection of Lutzomyia longipalpis SGS together with Leishmania infantum induced an early increased parasite viability in monocytes and neutrophils. L. longipalpis SGS increased prostaglandin E2 (PGE2), but reduced leukotriene B4 (LTB4) production ex vivo in peritoneal leukocytes. In addition, the pharmacological inhibition of cyclooxygenase 2 (COX-2) with NS-398 decreased parasite viability inside macrophages during Leishmania infection in the presence of L. longipalpis SGS arguing that PGE2 production is associated with diminished parasite killing. These findings indicate that L. longipalpis SGS is a critical factor driving immune evasion of Leishmania through modulation of PGE2/LTB4 axis, which may represent an important mechanism on establishment of the infection.

  3. Crispoic acid, a new compound from Laelia marginata (Orchidaceae), and biological evaluations against parasites, human cancer cell lines and Zika virus.

    Science.gov (United States)

    Belloto, Andrezza C; Souza, Gredson K; Perin, Paula C; Schuquel, Ivania T A; Santin, Silvana M O; Chiavelli, Lucas U R; Garcia, Francielle P; Kaplum, Vanessa; Rodrigues, Jean H S; Scariot, Débora B; Delvecchio, Rodrigo; Machado-Ferreira, Erik; Santana Aguiar, Renato; Soares, Carlos A G; Nakamura, Celso V; Pomini, Armando M

    2017-11-08

    The phytochemical study of Laelia marginata (Lindl.) L. O. Williams (Orchidaceae) led to the isolation of a new natural product named crispoic acid (1), together with six other known compounds (2-7). The new natural product was identified as a dimer of eucomic acid and was structurally characterised based upon 1D and 2D NMR and HRMS data. Biological assays with plant crude extract, fractions and isolated compounds were performed against two human cancer cell lines (Hela and Siha), and the tropical parasites Trypanosoma cruzi and Leishmania (Leishmania) amazonensis. The phenantrenoid 9,10-dihydro-4-methoxyphenanthren-2,7-diol 2 was active against Hela and Siha cells (CC 50 5.86 ± 0.19 and 20.78 ± 2.72 μg/mL, respectively). Sub-lethal concentrations of the flavone rhamnazin 4 were not able to rescue the viability of the Vero cells infected by Zika virus.

  4. Lipid Droplet Formation, Their Localization and Dynamics during Leishmania major Macrophage Infection.

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    Sameh Rabhi

    Full Text Available Leishmania, the causative agent of vector-borne diseases, known as leishmaniases, is an obligate intracellular parasite within mammalian hosts. The outcome of infection depends largely on the activation status of macrophages, the first line of mammalian defense and the major target cells for parasite replication. Understanding the strategies developed by the parasite to circumvent macrophage defense mechanisms and to survive within those cells help defining novel therapeutic approaches for leishmaniasis. We previously showed the formation of lipid droplets (LDs in L. major infected macrophages. Here, we provide novel insights on the origin of the formed LDs by determining their cellular distribution and to what extent these high-energy sources are directed to the proximity of Leishmania parasites. We show that the ability of L. major to trigger macrophage LD accumulation is independent of parasite viability and uptake and can also be observed in non-infected cells through paracrine stimuli suggesting that LD formation is from cellular origin. The accumulation of LDs is demonstrated using confocal microscopy and live-cell imagin in parasite-free cytoplasmic region of the host cell, but also promptly recruited to the proximity of Leishmania parasites. Indeed LDs are observed inside parasitophorous vacuole and in parasite cytoplasm suggesting that Leishmania parasites besides producing their own LDs, may take advantage of these high energy sources. Otherwise, these LDs may help cells defending against parasitic infection. These metabolic changes, rising as common features during the last years, occur in host cells infected by a large number of pathogens and seem to play an important role in pathogenesis. Understanding how Leishmania parasites and different pathogens exploit this LD accumulation will help us define the common mechanism used by these different pathogens to manipulate and/or take advantage of this high-energy source.

  5. Leishmania promastigotes lack phosphatidylserine but bind annexin V upon permeabilization or miltefosine treatment.

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    Adrien Weingärtner

    Full Text Available The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and (31P nuclear magnetic resonance (NMR spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining.

  6. Involvement of Leishmania donovani major surface glycoprotein ...

    Indian Academy of Sciences (India)

    The major surface glycoprotein gp63 of the kinetoplastid protozoal parasite Leishmania is implicated as a ligand mediating uptake of the parasite into, and survival within, the host macrophage. By expressing gp63 antisense RNA from an episomal vector in L. donovani promastigotes, gp63-deficient transfectants were ...

  7. Transmission of Leishmania in coffee plantations of Minas Gerais, Brazil

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    Bruce Alexander

    2002-07-01

    Full Text Available Transmission of Leishmania was studied in 27 coffee plantations in the Brazilian State of Minas Gerais. Eighteen females and six males (11.6% of the people tested, aged between 7-65 gave a positive response to the Montenegro skin test. Awareness of sand flies based on the ability of respondents to identify the insects using up to seven predetermined characteristics was significantly greater among inhabitants of houses occupied by at least one Mn+ve individual. Five species of phlebotomine sand fly, including three suspected Leishmania vectors, were collected within plantations under three different cultivation systems. Four of these species i.e., Lu. fischeri (Pinto 1926, Lu. migonei (França 1920, Lu. misionensis (Castro 1959 and Lutzomyia whitmani (Antunes & Coutinho 1939 were collected in an organic plantation and the last of these was also present in the other two plantation types. The remaining species, Lu. intermedia (Lutz & Neiva 1912, was collected in plantations under both the "adensado" and "convencional" systems. The results of this study indicate that transmission of Leishmania to man in coffee-growing areas of Minas Gerais may involve phlebotomine sand flies that inhabit plantations.

  8. The past, present, and future of Leishmania genomics and transcriptomics

    Science.gov (United States)

    Cantacessi, Cinzia; Dantas-Torres, Filipe; Nolan, Matthew J.; Otranto, Domenico

    2015-01-01

    It has been nearly 10 years since the completion of the first entire genome sequence of a Leishmania parasite. Genomic and transcriptomic analyses have advanced our understanding of the biology of Leishmania, and shed new light on the complex interactions occurring within the parasite–host–vector triangle. Here, we review these advances and examine potential avenues for translation of these discoveries into treatment and control programs. In addition, we argue for a strong need to explore how disease in dogs relates to that in humans, and how an improved understanding in line with the ‘One Health’ concept may open new avenues for the control of these devastating diseases. PMID:25638444

  9. Cutaneous leishmaniasis with lymphadenopathy due to Leishmania donovani

    NARCIS (Netherlands)

    Faber, W. R.; Wonders, J.; Jensema, A. J.; Chocholova, E.; Kager, P. A.

    2009-01-01

    Summary We describe a case of cutaneous leishmaniasis with lymphadenopathy due to Leishmania donovani, which was successfully treated with oral miltefosine. Given the increased prevalence of travelling, patients presenting with lymph-node enlargement should have leishmaniasis included in the

  10. Gluconeogenesis in Leishmania mexicana: contribution of glycerol kinase, phosphoenolpyruvate carboxykinase, and pyruvate phosphate dikinase.

    Science.gov (United States)

    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-11-21

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Naturally infected Lutzomyia sand flies in a Leishmania-endemic area of Brazil.

    Science.gov (United States)

    Carvalho, Gustavo M L; Andrade Filho, Jose D; Falcao, Alda L; Rocha Lima, Ana C V M; Gontijo, Celia M F

    2008-06-01

    In Brazil, Leishmania transmission involves several species of phlebotomine sand flies that are closely associated with different parasites and reservoirs, giving rise to different transmission cycles. The present study focused on naturally infected phlebotomines originating from Santa Luzia, a municipality near Belo Horizonte, capital of the Brazilian state of Minas Gerais, in which leishmaniasis are endemic. Systematic and non systematic approaches,involving the use of light traps and direct aspiration from resting sites, respectively, were used to collect females and flies. Identification of the captured insects and determination of natural infection by Leishmania spp. were performed using both conventional dissection methods and polymerase chain reaction (PCR). The dissection of 102 sand flies allowed five species of Lutzomyia to be identified, although no flagellate parasite forms were observed.In addition, 211 sand flies were identified, were separated according to species, and were combined into 11 pools of up to 20 individuals each. PCR analyses showed that two of these pools were infected with Leishmania:one pool of Lu. whitmani was infected with Le. (Viannia) spp. and another of Lu. cortelezzii was infected with Le. chagasi. This suggests that Lu. whitmani may be a possible vector of Leishmania in the study area, and more work needs to be performed to assess the role of Lu. cortelezzii as a vector.

  12. Molecular screening of Leishmania spp. infection and bloodmeals in sandflies from a leishmaniasis focus in southwestern Turkey.

    Science.gov (United States)

    Karaku Ş, M; Pekağ Irba Ş, M; Demir, S; Eren, H; Töz, S; Özbel, Y

    2017-06-01

    Leishmaniasis is an arthropod-borne disease that affects approximately 2 million people worldwide annually. The aims of this study were to detect the presence of Leishmania (Kinetoplastida: Trypanosomatidae) DNA and the feeding preferences of probable vector species in an endemic focus of Leishmania infantum in Turkey. Entomological sampling was performed in August and October 2015 in Aydın province, where cases of human and canine leishmaniasis have been reported previously. A total of 1059 sandfly specimens comprising nine species belonging to two genera, Phlebotomus and Sergentomyia (both: Diptera: Psychodidae), and five subgenera of the Phlebotomus genus (Phlebotomus, Paraphlebotomus, Larroussius, Adlerius and Transphlebotomus) were collected in five villages. Among all Phlebotomus specimens, Phlebotomus neglectus (39%) was noted as the most abundant species, followed by Phlebotomus tobbi (18%). Leishmania DNA was detected in pools from P. neglectus, P. tobbi and Sergentomyia dentata by kDNA polymerase chain reaction (PCR). Leishmania DNA from Phlebotomus specimens was identified as L. infantum, but Leishmania DNA from Sergentomyia spp. could not be identified to species level by ITS-1 real-time PCR. The detection of Leishmania DNA in wild-caught P. neglectus and the high percentage (24.2%) of human DNA in engorged specimens suggests that P. neglectus is probably an important vector species for L. infantum in Aydın province. © 2016 The Royal Entomological Society.

  13. In vitro and in vivo efficacy of ether lipid edelfosine against Leishmania spp. and SbV-resistant parasites.

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    Rubén E Varela-M

    Full Text Available BACKGROUND: The leishmaniases are a complex of neglected tropical diseases caused by more than 20 Leishmania parasite species, for which available therapeutic arsenal is scarce and unsatisfactory. Pentavalent antimonials (SbV are currently the first-line pharmacologic therapy for leishmaniasis worldwide, but resistance to these compounds is increasingly reported. Alkyl-lysophospoholipid analogs (ALPs constitute a family of compounds with antileishmanial activity, and one of its members, miltefosine, has been approved as the first oral treatment for visceral and cutaneous leishmaniasis. However, its clinical use can be challenged by less impressive efficiency in patients infected with some Leishmania species, including L. braziliensis and L. mexicana, and by proneness to develop drug resistance in vitro. METHODOLOGY/PRINCIPAL FINDINGS: We found that ALPs ranked edelfosine>perifosine>miltefosine>erucylphosphocholine for their antileishmanial activity and capacity to promote apoptosis-like parasitic cell death in promastigote and amastigote forms of distinct Leishmania spp., as assessed by proliferation and flow cytometry assays. Effective antileishmanial ALP concentrations were dependent on both the parasite species and their development stage. Edelfosine accumulated in and killed intracellular Leishmania parasites within macrophages. In vivo antileishmanial activity was demonstrated following oral treatment with edelfosine of mice and hamsters infected with L. major, L. panamensis or L. braziliensis, without any significant side-effect. Edelfosine also killed SbV-resistant Leishmania parasites in in vitro and in vivo assays, and required longer incubation times than miltefosine to generate drug resistance. CONCLUSIONS/SIGNIFICANCE: Our data reveal that edelfosine is the most potent ALP in killing different Leishmania spp., and it is less prone to lead to drug resistance development than miltefosine. Edelfosine is effective in killing Leishmania

  14. Estudo do papel funcional da cisteína sintase e da cistationina B-sintase na resposta ao estresse oxidativo e nitrosativo em leishmania (viannia) braziliensis, trypanosoma rangeli e trypanosoma cruzi

    OpenAIRE

    Romero Calderon, Ibeth Cristina

    2014-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia e Biociências, Florianópolis, 2014 Leishmania (Viannia) braziliensis, Trypanosoma rangeli e o Trypanosoma cruzi são parasitos hemoflagelados pertencentes à Ordem Kinetoplastida, família Trypanosomatidae, capazes de infectar insetos, animais silvestres e domésticos, assim como o homem. Durante seu ciclo de vida, estes parasitos são expostos a uma grande quanti...

  15. Can equids be a reservoir of Leishmania braziliensis in endemic areas?

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    Jessé Henrique Truppel

    Full Text Available In this study, we detected Leishmania (Viannia braziliensis infection in equids living in endemic regions of cutaneous leishmaniasis. To determine the role of these animals in the Leishmania cycle, we used two approaches: serological and molecular methods. Antibodies to the parasite were assayed using the Enzyme Linked Immunosorbent Assay (ELISA. Blood samples were collected and tested by polymerase chain reaction (PCR, and the positive products were sequenced. The results showed that 11.0% (25/227 of the equids were seropositive for Leishmania sp, and 16.3% (37/227 were PCR positive. Antibodies were detected in 20 horses, 3 donkeys, and 2 mules, and the parasite DNA was detected in 30 horses, 5 donkeys, and 2 mules. Sequencing the amplified DNA revealed 100% similarity with sequences for Viannia complex, corroborating the results of PCR for L. braziliensis. Our results show that equids are infected with L. braziliensis, which could be food sources for phlebotomines in the peridomiciliary environment and consequently play a role in the cutaneous leishmaniasis cycle.

  16. Leishmania (V.) braziliensis infecting bats from Pantanal wetland, Brazil: First records for Platyrrhinus lineatus and Artibeus planirostris.

    Science.gov (United States)

    de Castro Ferreira, Eduardo; Pereira, Agnes Antônio Sampaio; Silveira, Maurício; Margonari, Carina; Marcon, Glaucia Elisete Barbosa; de Oliveira França, Adriana; Castro, Ludiele Souza; Bordignon, Marcelo Oscar; Fischer, Erich; Tomas, Walfrido Moraes; Dorval, Maria Elizabeth Cavalheiros; Gontijo, Célia Maria Ferreira

    2017-08-01

    In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments

  17. The prevalence of canine Leishmania infantum infection in western China detected by PCR and serological tests

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    Chen Hai-Tang

    2011-05-01

    Full Text Available Abstract Background Canine leishmaniasis (CanL is endemic in western China, resulting in important public health problem. It is essential to evaluate the prevalence of canine Leishmania infantum infection for designing control policy. In the present study we report for the first time prevalence of Leishmania infection in dogs living in Jiuzhaigou County (Sichuan Provence, China, which is not only an important endemic area of CanL but also a tourism scenic spot, detected by PCR, ELISA and dipstick test. The results could provide key information for designing control programs against canine and human leishmaniasis. In addition, the complete sequence of the Leishmania isolate from Sichuan Province has not been reported to date and we present the sequences of 116 base-pair (bp fragment of the conserved region in the minicircle kinetoplast DNA (kDNA and the results of phylogenetic analyses based on the sequence of the amplified fragment. Results The proportion of dogs infected with Leishmania in Jiuzhaigou County was 36.79%, 9.43%, and 51.88% detected by ELISA, dipstick test, and PCR, respectively. The ELISA and PCR tests were more sensitive than dipstick test. The PCR method is the most sensitive way to detect dogs infected with Leishmania parasites. The total positive rate for infected dogs in the area was 59.43% by the three methods. The PCR products of 116-bp fragment amplified from the kDNA conserved region of dog blood samples and laboratory maintained L. infantum were DNA sequenced and the variation of the sequences was observed. The phylogenetic tree based on the sequences of 116-bp fragment reveals that L. infantum is more genetically related to visceralizing species L. donovani than to the Leishmania species associated with cutaneous disease. Conclusions More than half of dogs living in the endemic Jiuzhaigou County were infected by L. infantum. Control measures, such as treatment or eradication of infected dogs, or prohibition of

  18. Assessment of nuclear and mitochondrial genes in precise identification and analysis of genetic polymorphisms for the evaluation of Leishmania parasites.

    Science.gov (United States)

    Fotouhi-Ardakani, Reza; Dabiri, Shahriar; Ajdari, Soheila; Alimohammadian, Mohammad Hossein; AlaeeNovin, Elnaz; Taleshi, Neda; Parvizi, Parviz

    2016-12-01

    The polymorphism and genetic diversity of Leishmania genus has status under discussion depending on many items such as nuclear and/or mitochondrial genes, molecular tools, Leishmania species, geographical origin, condition of micro-environment of Leishmania parasites and isolation of Leishmania from clinical samples, reservoir host and vectors. The genetic variation of Leishmania species (L. major, L. tropica, L. tarentolae, L. mexicana, L. infantum) were analyzed and compared using mitochondrial (COII and Cyt b) and nuclear (nagt, ITS-rDNA and HSP70) genes. The role of each enzymatic (COII, Cyt b and nagt) or housekeeping (ITS-rDNA, HSP70) gene was employed for accurate identification of Leishmania parasites. After DNA extractions and amplifying of native, natural and reference strains of Leishmania parasites, polymerase chain reaction (PCR) products were sequenced and evaluation of genetic proximity and phylogenetic analysis were performed using MEGA6 and DnaSP5 software. Among the 72 sequences of the five genes, the number of polymorphic sites was significantly lower as compared to the monomorphic sites. Of the 72 sequences, 54 new haplotypes (five genes) of Leishmania species were submitted in GenBank (Access number: KU680818 - KU680871). Four genes had a remarkable number of informative sites (P=0.00), except HSP70 maybe because of its microsatellite regions. The non-synonymous (dN) variants of nagt gene were more than that of other expression genes (47.4%). The synonymous (dS)/dN ratio in three expression genes showed a significant variation between five Leishmania species (P=0.001). The highest and lowest levels of haplotype diversity were observed in L. tropica (81.35%) and L. major (28.38%) populations, respectively. Tajima's D index analyses showed that Cyt b gene in L. tropica species was significantly negative (Tajima's D=-2.2, PLeishmania parasites. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Leishmania attachment in permissive vectors and the role of sand fly midgut proteins in parasite-vector interaction

    OpenAIRE

    Dostálová, Anna

    2012-01-01

    of PhD. thesis named "Leishmania attachment in permissive vectors and the role of sand fly midgut proteins in parasite-vector interaction", Anna Dostálová, 2011 This thesis focuses on the development of protozoan parasites of the genus Leishmania in their insect vectors, sand flies. It sums up results of three projects I was involved in during my PhD studies. Main emphasis was put on permissive sand fly species that support development of various species of Leishmania. Using a novel method of...

  20. Detection and identification of Leishmania spp.: application of two hsp70-based PCR-RFLP protocols to clinical samples from the New World.

    Science.gov (United States)

    Montalvo, Ana M; Fraga, Jorge; Tirado, Dídier; Blandón, Gustavo; Alba, Annia; Van der Auwera, Gert; Vélez, Iván Darío; Muskus, Carlos

    2017-07-01

    Leishmaniasis is highly prevalent in New World countries, where several methods are available for detection and identification of Leishmania spp. Two hsp70-based PCR protocols (PCR-N and PCR-F) and their corresponding restriction fragment length polymorphisms (RFLP) were applied for detection and identification of Leishmania spp. in clinical samples recruited in Colombia, Guatemala, and Honduras. A total of 93 cases were studied. The samples were classified into positive or suspected of leishmaniasis according to parasitological criteria. Molecular amplification of two different hsp70 gene fragments and further RFLP analysis for identification of Leishmania species was done. The detection in parasitologically positive samples was higher using PCR-N than PCR-F. In the total of samples studied, the main species identified were Leishmania panamensis, Leishmania braziliensis, and Leishmania infantum (chagasi). Although RFLP-N was more efficient for the identification, RFLP-F is necessary for discrimination between L. panamensis and Leishmania guyanesis, of great importance in Colombia. Unexpectedly, one sample from this country revealed an RFLP pattern corresponding to Leishmania naiffi. Both molecular variants are applicable for the study of clinical samples originated in Colombia, Honduras, and Guatemala. Choosing the better tool for each setting depends on the species circulating. More studies are needed to confirm the presence of L. naiffi in Colombian territory.

  1. Comparison of codon usage bias across Leishmania and Trypanosomatids to understand mRNA secondary structure, relative protein abundance and pathway functions.

    Science.gov (United States)

    Subramanian, Abhishek; Sarkar, Ram Rup

    2015-10-01

    Understanding the variations in gene organization and its effect on the phenotype across different Leishmania species, and to study differential clinical manifestations of parasite within the host, we performed large scale analysis of codon usage patterns between Leishmania and other known Trypanosomatid species. We present the causes and consequences of codon usage bias in Leishmania genomes with respect to mutational pressure, translational selection and amino acid composition bias. We establish GC bias at wobble position that governs codon usage bias across Leishmania species, rather than amino acid composition bias. We found that, within Leishmania, homogenous codon context coding for less frequent amino acid pairs and codons avoiding formation of folding structures in mRNA are essentially chosen. We predicted putative differences in global expression between genes belonging to specific pathways across Leishmania. This explains the role of evolution in shaping the otherwise conserved genome to demonstrate species-specific function-level differences for efficient survival. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Computational prediction of protein-protein interactions in Leishmania predicted proteomes.

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    Antonio M Rezende

    Full Text Available The Trypanosomatids parasites Leishmania braziliensis, Leishmania major and Leishmania infantum are important human pathogens. Despite of years of study and genome availability, effective vaccine has not been developed yet, and the chemotherapy is highly toxic. Therefore, it is clear just interdisciplinary integrated studies will have success in trying to search new targets for developing of vaccines and drugs. An essential part of this rationale is related to protein-protein interaction network (PPI study which can provide a better understanding of complex protein interactions in biological system. Thus, we modeled PPIs for Trypanosomatids through computational methods using sequence comparison against public database of protein or domain interaction for interaction prediction (Interolog Mapping and developed a dedicated combined system score to address the predictions robustness. The confidence evaluation of network prediction approach was addressed using gold standard positive and negative datasets and the AUC value obtained was 0.94. As result, 39,420, 43,531 and 45,235 interactions were predicted for L. braziliensis, L. major and L. infantum respectively. For each predicted network the top 20 proteins were ranked by MCC topological index. In addition, information related with immunological potential, degree of protein sequence conservation among orthologs and degree of identity compared to proteins of potential parasite hosts was integrated. This information integration provides a better understanding and usefulness of the predicted networks that can be valuable to select new potential biological targets for drug and vaccine development. Network modularity which is a key when one is interested in destabilizing the PPIs for drug or vaccine purposes along with multiple alignments of the predicted PPIs were performed revealing patterns associated with protein turnover. In addition, around 50% of hypothetical protein present in the networks

  3. Reconstrucción quirúrgica tras destrucción nasal por Leishmania Panamensis Surgical reconstruction after nasal destruction by Leishmania Panamensis

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    F. Vélez Bernal

    2013-03-01

    Full Text Available Algunas especies de Leishmania del subgénero Viannia, especialmente Leishmania braziliensis y Leishmania panamensis, pueden invadir la mucosa naso-orofaríngea al diseminarse por vía linfática y sanguínea a partir de una lesión cutánea y ocasionar lesiones en el tabique nasal, paladar blando, úvula, pilares amigdalinos, laringe, faringe, dorso nasal, labios y pómulos, que pueden conducir a la desfiguración. La mucosa más frecuentemente afectada es la del tabique nasal, principalmente en su parte anterior. La invasión de la mucosa puede ocurrir simultáneamente con lesiones cutáneas activas, aunque más frecuentemente aparecen 1 o 2 años después de la lesión en la piel; sin embargo, en el 16 % de los casos no hay antecedentes de lesiones cutáneas, lo que sugiere que con la picadura del insecto vector se produjo una infección primaria asintomática u oligosintomática y luego se produjo la diseminación del parasito a la mucosas. En este artículo presentamos 2 casos clínicos de leishmaniosis mucosa producidos por L. panamensis y los procedimientos quirúrgicos reconstructivos que se realizaron. Se hace además un recuento de los diagnósticos diferenciales en tejidos oronasales.Species of Leishmania of Viannia subgenus, mainly L. braziliensis and L. panamensis, may invade the nasooro-pharyngeal mucosal after spread from the skin lesion via lymph and blood, causing lesions in the nasal septum, soft palate, uvula, tonsillar pillars, larynx, pharynx, nasal dorsum, lips and cheeks. The mucosal membrane most frequently affected is the nasal septum, mainly in the anterior region. The invasion of mucosa may occur simultaneously with active skin lesions, but most often appear 1 or 2 years after the skin lesion; nevertheless, in 16 % of cases there is no history of skin lesions suggesting that the primary infection coursed with few symptoms and then was spread to mucosal membranes. In this article 2 cases of L panamensis mucosal

  4. Immunopathological Features of Canine Myocarditis Associated with Leishmania infantum Infection

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    Alessandro Costagliola

    2016-01-01

    Full Text Available Myocarditis associated with infectious diseases may occur in dogs, including those caused by the protozoa Neospora caninum, Trypanosoma cruzi, Babesia canis, and Hepatozoon canis. However, although cardiac disease due to Leishmania infection has also been documented, the immunopathological features of myocarditis have not been reported so far. The aim of this study was to examine the types of cellular infiltrates and expression of MHC classes I and II in myocardial samples obtained at necropsy from 15 dogs with an established intravitam diagnosis of visceral leishmaniasis. Pathological features of myocardium were characterized by hyaline degeneration of cardiomyocytes, necrosis, and infiltration of mononuclear inflammatory cells consisting of lymphocytes and macrophages, sometimes with perivascular pattern; fibrosis was also present in various degrees. Immunophenotyping of inflammatory cells was performed by immunohistochemistry on cryostat sections obtained from the heart of the infected dogs. The predominant leukocyte population was CD8+ with a fewer number of CD4+ cells. Many cardiomyocytes expressed MHC classes I and II on the sarcolemma. Leishmania amastigote forms were not detected within macrophages or any other cell of the examined samples. Our study provided evidence that myocarditis in canine visceral leishmaniasis might be related to immunological alterations associated with Leishmania infection.

  5. Identification of Leishmania spp. promastigotes in the intestines, ovaries, and salivary glands of Rhipicephalus sanguineus actively infesting dogs.

    Science.gov (United States)

    Viol, Milena Araúz; Guerrero, Felix D; de Oliveira, Bruno César Miranda; de Aquino, Monally Conceição Costa; Loiola, Saulo Hudson; de Melo, Guilherme Dias; de Souza Gomes, Aparecida Helena; Kanamura, Cristina Takami; Garcia, Marcos Valério; Andreotti, Renato; de Lima, Valéria Marçal Félix; Bresciani, Katia Denise Saraiva

    2016-09-01

    Sand flies are recognized as the major vector of canine visceral leishmaniasis. However, in some areas of Brazil where sand flies do not occur, this disease is found in humans and dogs. There has been speculation that ticks might play a role in transmission of canine visceral leishmaniasis and the DNA of Leishmania spp. has been reported in whole ticks. We investigated the presence of Leishmania spp. promastigotes in the intestines, ovaries, and salivary glands of Rhipicephalus sanguineus ticks collected from tick-infested dogs in two cities of Brazil. We used 66 dogs that tested positive and 33 that tested negative for Leishmania spp. according to direct cytological examination assays. Ten ticks were collected from each dog and dissected to collect the intestines, ovaries, and salivary glands for immunohistochemistry (IHC) and diagnostic real-time polymerase chain reaction (RT-PCR). IHC results showed Leishmania spp. in 98, 14, and 8 % of the intestines, ovaries, and salivary glands, respectively. Real-time PCR showed that 89, 41, and 33 % of the tick intestine, ovary, and salivary glands, respectively, were positive for Leishmania spp. The verification of promastigotes of Leishmania spp. by two independent techniques in ticks collected from these urban region dogs showed that there is need for clarification of the role of ticks in the transmission of canine visceral leishmaniasis in Brazil.

  6. Novel features of a PIWI-like protein homolog in the parasitic protozoan Leishmania.

    Directory of Open Access Journals (Sweden)

    Prasad K Padmanabhan

    Full Text Available In contrast to nearly all eukaryotes, the Old World Leishmania species L. infantum and L. major lack the bona fide RNAi machinery genes. Interestingly, both Leishmania genomes code for an atypical Argonaute-like protein that possesses a PIWI domain but lacks the PAZ domain found in Argonautes from RNAi proficient organisms. Using sub-cellular fractionation and confocal fluorescence microscopy, we show that unlike other eukaryotes, the PIWI-like protein is mainly localized in the single mitochondrion in Leishmania. To predict PIWI function, we generated a knockout mutant for the PIWI gene in both L. infantum (Lin and L. major species by double-targeted gene replacement. Depletion of PIWI has no effect on the viability of insect promastigote forms but leads to an important growth defect of the mammalian amastigote lifestage in vitro and significantly delays disease pathology in mice, consistent with a higher expression of the PIWI transcript in amastigotes. Moreover, amastigotes lacking PIWI display a higher sensitivity to apoptosis inducing agents than wild type parasites, suggesting that PIWI may be a sensor for apoptotic stimuli. Furthermore, a whole-genome DNA microarray analysis revealed that loss of LinPIWI in Leishmania amastigotes affects mostly the expression of specific subsets of developmentally regulated genes. Several transcripts encoding surface and membrane-bound proteins were found downregulated in the LinPIWI((-/- mutant whereas all histone transcripts were upregulated in the null mutant, supporting the possibility that PIWI plays a direct or indirect role in the stability of these transcripts. Although our data suggest that PIWI is not involved in the biogenesis or the stability of small noncoding RNAs, additional studies are required to gain further insights into the role of this protein on RNA regulation and amastigote development in Leishmania.

  7. [Leishmaniasis in Ecuador. 4. Natural infestation of the dog by Leishmania panamensis].

    Science.gov (United States)

    Dereure, J; Espinel, I; Barrera, C; Guerrini, F; Martini, A; Echeverria, R; Guderian, R H; Le Pont, F

    1994-03-01

    In two endemic leishmaniasis foci of the Pacific coast of Ecuador 34 dogs suspected of having the disease have been surveyed clinically, serologically and parasitologically; immunofluorescence and electrosyneresis tests, lymph node aspirates, biopsies and smears have been performed. From two dogs with ulcers only one had ulcers on the muzzle and the scrotum infected by Leishmania (L. guyanensis complex). The isolated strain was identified as Leishmania panamensis. The disease was strictly cutaneous. In the study area the dog seems to be more a victim-host than a reservoir.

  8. Bibliography of Leishmania and Leishmanial Diseases. Volume 2

    Science.gov (United States)

    1980-08-01

    Leishmaniosi visceizile latente in adulto rivelatasi PHOTINOS, P. B, (1930A) Formes atypiques nel corso di una, Infezione tifoidea . N infiltries en... fiebre recurrente y con gran flagelle’s au cours des leishmanioses cantidad de leishmanias en sangre penl- ’cliniques et expegrinientales. Ann.ferlca

  9. Biosynthesis of silver nanoparticles by Leishmania tropica | Rahi ...

    African Journals Online (AJOL)

    A novel biosynthesis route for Silver Nanoparticles (Ag-NPs) was attempted in the present study using Leishmania tropica the causative agent of cutaneous leishmaniasis in different countries, particularly in Mediterranean region in Iraq. Silver nanoparticles were successfully synthesized from AgNO3 by reduction of ...

  10. Novel Leishmania and Malaria Potassium Channels: Candidate Therapeutic Targets

    National Research Council Canada - National Science Library

    McDonald, Thomas V

    2005-01-01

    .... major and T. cruzi). Using a combination of cultured mammalian cells and Xenopus oocytes for heterologous expression we have evidence that 2 channels from malaria [PFK1 & PFK22] and Leishmania [LMK1 & LMK2] generate K+...

  11. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    Energy Technology Data Exchange (ETDEWEB)

    Bisacchi, Davide [Bioinformatics and Structural Proteomics, IST-National Cancer Research Institute, Genova (Italy); Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita [Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan (United States); Bordo, Domenico, E-mail: domenico.bordo@istge.it [Bioinformatics and Structural Proteomics, IST-National Cancer Research Institute, Genova (Italy)

    2006-10-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3{sub 1}21/P3{sub 2}21). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å.

  12. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    International Nuclear Information System (INIS)

    Bisacchi, Davide; Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita; Bordo, Domenico

    2006-01-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3 1 21/P3 2 21). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å

  13. Xenodiagnostico con Lutzomyia youngi en casos venezolanos de leishmaniasis cutaned por Leishmania braziliensis Xenodiagnosis with Lutzomyia youngi in Venezuelan cases of cutaneous leishmaniais due to Leishmania braziliensis

    Directory of Open Access Journals (Sweden)

    Elina Rojas

    1989-03-01

    Full Text Available Xenodiagnósticos con Lutzomya yungi aplicados en los bordes de las úlceras de pacientes infectados con Leishmania braziliensis antes y después del tratamiento con 10 dosis de antimonial pentavalente y un aminoglicósido, evidencian la condición reservoria de leishmanias del enfermo, para flebótomos endofágicos y la utilidad de un tratamiento específico-temprano que no solamente conduce a la curación clínica, sino a la eliminación del riesgo de una eventual transmisión intradomiciliar por insectos que pican dentro del domicilio durante la noche.Eight patients infected with Leishmania braziliensis were used for xenodiagnosis with Lutzomtyia youngi, before and after specific antileishmanial treatment with "glucantime" and "gabbromycin". All of them infected sandflies fed on the borders of the skin lesions before the treatment, suggesting that infected persons might act as reservoirs of infection for an indoor-bitting sandfly species. The negative results obtained by xenodiagnosis carried out after specific treatment of the same individuals indicated cure of the patients, and a reduction of risk for further intradomiciliary transmission.

  14. Receptor-Mediated Drug Delivery to Macrophages in Chemotherapy of Leishmaniasis

    Science.gov (United States)

    Mukhopadhyay, Amitabha; Chaudhuri, Gautam; Arora, Sunil K.; Sehgal, Shobha; Basu, Sandip K.

    1989-05-01

    Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the ``scavenger'' receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases.

  15. Infecção experimental de Calomys callosus (Rengger, 1830, (Cricetidae - Rodentia a quatro espécies de parasitos

    Directory of Open Access Journals (Sweden)

    Dalva A. Mello

    1980-12-01

    Full Text Available Neste trabalho foram estudados exemplares do roedor, Calomys callosus, nascidos em laboratório, a infecções experimentais com quatro parasitos: Plasmodium berghei, Leishmania mexicana amazonensis, Schistosoma mansoni e Hymenolepsis nana. A positividade das infecções foi de 80% para os três primeiros parasitos e 0 para H. nana. C. callosus é um roedor de excelente adaptação em laboratório e de fácil manuseio. Acredita-se que, de acordo com os resultados obtidos neste trabalho, este animal poderia ser um bom modelo experimental de laboratório para certos agentes patogênicos.

  16. Expression of hsa Let-7a MicroRNA of Macrophages Infected by Leishmania Major

    Directory of Open Access Journals (Sweden)

    Nooshin Hashemi

    2016-10-01

    Full Text Available Leishmaniasis is a vector-born disease caused by species of the genus Leishmania and is transmitted from host to host through the bite of an infected sandfly. MicroRNAs (miRNAs are non-coding small RNAs with 22-nucleotide length. They are involved in some biological and cellular processes. We aimed to evaluate the expression of let-7a in human macrophages miRNA when are infected by Leishmania major. We also evaluated the impact of Leishmania major infection on the expression of let-7a at two different times, 24 and 48 hours, after infection. Blood samples were collected from ten healthy volunteers with no history of leishmaniasis. Development of macrophages from peripheral monocytes and infection with stationary phase of Leishmania major promastigotes were done through serial cultures under 5% CO2 environment and 37C. To measure the expression levels of let-7a real-time PCR was performed with specific related primers using the SYBR® Green master mix Kit™. The real-time PCR showed let-7a was expressed in cells infected with parasites after 24 and 48h post-infection. Comparison of let-7a miRNA expression after 24 and 48 h revealed that let-7a miRNAs were down-regulated at 48 h post-infection more than 24h after infection. The results of this study suggest that according to the main function of miRNA in repression of mRNA translation it could be possible to manipulate host cells in order to alter miRNA levels and regulate macrophage functions after establishment of intracellular parasites such as Leishmania.

  17. Studies on Stibanate unresponsive isolates of Leishmania donovani

    Indian Academy of Sciences (India)

    Unknown

    503. Keywords. Drug resistance; Leishmania donovani; sodium stibogluconate; visceral leishmaniasis ... cases to less than 5% in treated ones (Zuckerman and. Lainson 1977). Later on .... Effect of Stibanate on in vitro growth of Ag83 promastigotes. (A) Virulent .... In rural areas where health care facilities are not adequate ...

  18. Tetracycline-inducible gene expression system in Leishmania mexicana

    Czech Academy of Sciences Publication Activity Database

    Kraeva, N.; Ishemgulova, A.; Lukeš, Julius; Yurchenko, Vyacheslav

    2014-01-01

    Roč. 198, č. 1 (2014), s. 11-13 ISSN 0166-6851 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Leishmania mexicana * Gene expression * Tet-inducible system Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.787, year: 2014

  19. Leishmaniases in Ecuador: Comprehensive review and current status.

    Science.gov (United States)

    Hashiguchi, Yoshihisa; Velez, Lenin N; Villegas, Nancy V; Mimori, Tatsuyuki; Gomez, Eduardo A L; Kato, Hirotomo

    2017-02-01

    This article reviews current knowledge about leishmaniases in Ecuador, proceeding from 1920, when the first human case was described, to the present, mainly focusing on the recent research events published. Regarding basic situations, it appears that 23 of Ecuador's 24 provinces have leishmaniasis-case reports. The disease is one of the mandatory notification infectious diseases in the country since 2005. All the 21,305 cases notified to the Ministry of Public Health, during the period from 2001 through 2014, were said to involve different clinical features of cutaneous leishmaniasis (CL) but not visceral (VL). Eight Leishmania species, L. (Viannia) guyanensis, L. (V.) panamensis, L. (V.) braziliensis, L. (Leishmania) mexicana, L. (L.) amazonensis, L. (L.) major-like, L. (V.) naiffiand L. (V.) lainsoni were characterized. The last two species were most recently reported from the Ecuadorian Amazon regions. Of the 73 Ecuadorian Lutzomyia species (43 man-biting species) recorded, only four, Lu. trapidoi, Lu. gomezi, Lu. ayacuchensis, and Lu. tortura were incriminated as vectors of the Leishmania parasites. Current knowledge on the reservoir hosts of Leishmania in Ecuador is extremely poor. Recently, in Ecuador different kinds of molecular techniques were developed for diagnosis and mass screening of the disease, employing various materials derived from patients and sand fly vectors. These are PCR-RFLP, colorimetric FTA-LAMP etc. Brief comments and recommendations were also given, for future research and control of leishmaniases in Ecuador. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. MHC class II restricted innate-like double negative T cells contribute to optimal primary and secondary immunity to Leishmania major.

    Science.gov (United States)

    Mou, Zhirong; Liu, Dong; Okwor, Ifeoma; Jia, Ping; Orihara, Kanami; Uzonna, Jude Ezeh

    2014-09-01

    Although it is generally believed that CD4(+) T cells play important roles in anti-Leishmania immunity, some studies suggest that they may be dispensable, and that MHC II-restricted CD3(+)CD4(-)CD8(-) (double negative, DN) T cells may be more important in regulating primary anti-Leishmania immunity. In addition, while there are reports of increased numbers of DN T cells in Leishmania-infected patients, dogs and mice, concrete evidence implicating these cells in secondary anti-Leishmania immunity has not yet been documented. Here, we report that DN T cells extensively proliferate and produce effector cytokines (IFN-γ, TNF and IL-17) and granzyme B (GrzB) in the draining lymph nodes and spleens of mice following primary and secondary L. major infections. DN T cells from healed mice display functional characteristics of protective anti-Leishmania memory-like cells: rapid and extensive proliferation and effector cytokines production following L. major challenge in vitro and in vivo. DN T cells express predominantly (> 95%) alpha-beta T cell receptor (αβ TCR), are Leishmania-specific, restricted mostly by MHC class II molecules and display transcriptional profile of innate-like genes. Using in vivo depletion and adoptive transfer studies, we show that DN T cells contribute to optimal primary and secondary anti-Leishmania immunity in mice. These results directly identify DN T cells as important players in effective and protective primary and secondary anti-L. major immunity in experimental cutaneous leishmaniasis.