WorldWideScience
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Clonaje de la proteína de choque térmico de 20 kDa de Leishmania amazonensis / Cloning of 20 kDa heat shock protein of Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish INTRODUCCIÓN: la inducción de las proteínas de choque térmico constituyen un mecanismo homeostático que protege a las células del efecto destructivo del calor u otras condiciones de estrés ambiental, paralelamente, ellas cumplen importantes funciones celulares. La proteína de choque térmico de 20 kD [...] a se reportó recientemente en Leishmania amazonensis. OBJETIVO: describir la metodología utilizada para realizar el clonaje de las proteínas de choque térmico, lo que permitió acometer estudios de algunas propiedades biológicas. MÉTODOS: la región codificante del gen hsp20 se amplificó mediante la reacción en cadena de la polimerasa con cebadores adecuados. El producto amplificado se clonó inicialmente en el vector pCR2.1 (Invitrogen) y después en el vector de expresión en procariotas pET-28b (Novagen), para obtener proteína recombinante. De manera paralela, el mismo fragmento se clonó en el vector de expresión en eucariotas pcDNA3 (Invitrogen) para obtener un posible preparado vacunal de ADN. Se realizó la secuenciación nucleotídica de los clones obtenidos, con la finalidad de verificar su fidelidad. RESULTADOS: se obtuvieron plásmidos recombinantes que codifican la HSP20 de Leishmania, y permiten la obtención de proteína recombinante y de ADN en forma masiva. CONCLUSIONES: ambos plásmidos fueron útiles para estudiar algunas de las propiedades biológicas de esta proteína. Este acercamiento puede ser de interés en otros trabajos de esta índole y constituir una guía metodológica. Abstract in english INTRODUCTION: the induction of heat shock proteins is a homeostatic mechanism that protects cells from the deleterious effects of thermal and other environmental stresses. In addition, they have important cell functions. The 20kDa heat shock protein in Leishmania amazonensis was recently reported. O [...] BJECTIVE: to describe the methodology used for cloning of heat shock proteins, which allowed the study of some biological properties. METHODS: the hsp20 gene coding region was amplified by polymerase chain reaction using adequate primers. The amplified product was initially cloned in pCR2.1 vector (Invitrogen) and then in pET-28b vector (Novagen), to obtain recombinant protein. The same fragment was cloned also in the eukariote expression vector pcDNA3 (Invitrogen). The nucleotidic sequencing of the different clones was made, in order to verify their fidelity. RESULTS: the recombinant plasmids that encode HSP20 protein in Leishmania and allow obtaining massively recombinant protein and DNA were produced. CONCLUSIONS: both plasmids were useful to study some of the biological properties of this protein. This approach could be useful for similar research and represent a suitable methodological guideline.

Ana Margarita, Montalvo Álvarez; Cristina, Folgueira Fernández; José María, Requena Rolanía.

2009-08-01

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

Scientific Electronic Library Online (English)

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.

José Andrés, Morgado-Díaz; Raquel Elisa da, Silva-Lopez; Carlos Roberto, Alves; Maurilio José, Soares; Suzana, Corte-Real; Salvatore Giovanni, De Simone.

2005-07-01

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

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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.

José Andrés Morgado-Díaz

2005-07-01

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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  

Scientific Electronic Library Online (English)

Full Text Available 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 enzim [...] áticos 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 imaturos nas lesões crônicas induzidas neste sistema por Leishmania mexicana amazonensis. Abstract in english 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 we [...] ll-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.

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

1988-03-01

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Role of Leishmania (Leishmania) amazonensis amastigote glycosphingolipids in macrophage infectivity  

Scientific Electronic Library Online (English)

Full Text Available The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpß1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduc [...] ed by 37% when the disaccharide Galpß1-3Galp (1 mM) was added to the culture medium. The putative macrophage receptor/lectin for ß-Gal-globotriaosylceramide (Galpß1-3Galpa1-4Galpß1-4Glc pß1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by micelles and parasite binding assay to peritoneal macrophage proteins fractionated by SDS-PAGE under nonreducing conditions. Micelles containing purified amastigote GSLs or a suspention of L. (L.) amazonensis amastigotes fixed with 2% formaldehyde were incubated with nitrocellulose membrane containing the macrophage proteins transferred by Western blotting. Binding of micelles containing purified GSLs from amastigote forms or fixed L. (L.) amazonensis amastigotes to nitrocellulose membrane was probed using monoclonal antibody ST-3, which recognizes the glycoepitope Galpß1-3Galpa1-R present either in the micelle preparation or on the amastigote surface. Macrophage protein with molecular mass ~30 kDa bound the amastigote GSL and appeared to be a doublet on electrophoresis. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as ß-Galp-globotriaosylceramides, and which do not bind to 30-kDa protein.

A.K., Tanaka; P.A.J., Gorin; H.K., Takahashi; A.H., Straus.

2007-06-01

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The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite  

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Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mex...

Tschoeke, Diogo A.; Nunes, Gisele L.; Rodrigo Jardim; Joana Lima; Sr, Aline Dumaresq; Gomes, Monete R.; Leandro de Mattos Pereira; Loureiro, Daniel R.; Stoco, Patricia H.; Herbert Leonel de Matos Guedes; Antonio Basilio de Miranda; Jeronimo Ruiz; André Pitaluga; Silva Jr, Floriano P.; Probst, Christian M.

2014-01-01

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The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite.  

Science.gov (United States)

Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the "Mexicana complex", reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development. PMID:25336895

Tschoeke, Diogo A; Nunes, Gisele L; Jardim, Rodrigo; Lima, Joana; Dumaresq, Aline Sr; Gomes, Monete R; de Mattos Pereira, Leandro; Loureiro, Daniel R; Stoco, Patricia H; de Matos Guedes, Herbert Leonel; de Miranda, Antonio Basilio; Ruiz, Jeronimo; Pitaluga, André; Silva, Floriano P; Probst, Christian M; Dickens, Nicholas J; Mottram, Jeremy C; Grisard, Edmundo C; Dávila, Alberto Mr

2014-01-01

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Leishmaniose cutânea experimental. III- Aspectos histopatológicos do comportamento evolutivo da lesão cutânea produzida em Cebus apella (Primates: Cebidae) por Leishmania (Viannia) lainsoni, L. (V.) braziliensis e L. (Leishmania) amazonensis / Experimental cutaneous Leishmaniasis: III -Histopathological aspects of the evolution of cutaneous lesions produced in Cebus apella (Primates: Cebidae) by Leishmania (Viannia) lainsoni, L. (V.) braziliensis and L. (Leishmania) amazonensis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudaram-se os aspectos histopatológicos relativos à evolução da infecção experimental produzida em Cebus apella (Primates: Cebidae) por Leishmania (V.) lainsoni, L. (V.) braziliensis e L. (L.) amazonensis. O exame microscópico de biópsias seqüênciais, obtidas dos animais a intervalos definidos de [...] tempo (a primeira, às 48 ou 72 horas após a inoculação, e as seguintes, a cada 30 dias), mostrou que o desenvolvimento das lesões, independentemente da espécie de Leishmania inoculada, passa por uma seqüência de etapas a nível tecidual - 1) infiltrado inespecífico crônico; 2) nódulo macrofágico (com numerosos parasitas); 3) necrose das células parasitadas; 4) granuloma epitelióide; 5) absorção da área necrosada (às vezes formando granuloma de corpo estranho); 6) infiltrado inespecífico crônico residual); e 7) cicatrização - que representaria a formação e a resolução das lesões. Discutiram-se também os prováveis mecanismos imunopatológicos que determinam esta seqüência de eventos e sua possível semelhança com a evolução das lesões na leishmaniose tegumentar humana. Abstract in english We have studied the histopathological aspects related to the evolution of cutaneous lesions experimentally produced in the monkey Cebus apella (Primates: Cebidae) by Leishmania (V.) lainsoni, L. (V.) braziliensis and L. (L.) amazonensis. Microscopical examination of a serie of biopsies obtained from [...] these animals showed the kinetics of the cutaneous lesions regarding three species of Leishmania inoculated, as follows: 1) an initial non-specific chronic inflammatory infiltrate; 2) macrophagic nodules; 3) necrosis of parasitized phagocytic cells; 4) epithelioide granuloma; 5) absorption of the necrotic area (sometimes forming "foreign-body granuloma"); 6) a non-specific residual inflammatory infiltration; and 7) cicatrization. These pathological processes are, of course, responsible for both development and resolution of the leishmaniotic lesion. We also discuss some immunopathological mechanisms probably related with the sequencial events, and that could be also responsible for the different clinical aspects found in man.

Fernando T., Silveira; Mário A. P., Moraes; Ralph, Lainson; Jeffrey J., Shaw.

1990-12-01

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Leishmaniose cutânea experimental. III- Aspectos histopatológicos do comportamento evolutivo da lesão cutânea produzida em Cebus apella (Primates: Cebidae por Leishmania (Viannia lainsoni, L. (V. braziliensis e L. (Leishmania amazonensis Experimental cutaneous Leishmaniasis: III -Histopathological aspects of the evolution of cutaneous lesions produced in Cebus apella (Primates: Cebidae by Leishmania (Viannia lainsoni, L. (V. braziliensis and L. (Leishmania amazonensis  

Directory of Open Access Journals (Sweden)

Full Text Available Estudaram-se os aspectos histopatológicos relativos à evolução da infecção experimental produzida em Cebus apella (Primates: Cebidae por Leishmania (V. lainsoni, L. (V. braziliensis e L. (L. amazonensis. O exame microscópico de biópsias seqüênciais, obtidas dos animais a intervalos definidos de tempo (a primeira, às 48 ou 72 horas após a inoculação, e as seguintes, a cada 30 dias, mostrou que o desenvolvimento das lesões, independentemente da espécie de Leishmania inoculada, passa por uma seqüência de etapas a nível tecidual - 1 infiltrado inespecífico crônico; 2 nódulo macrofágico (com numerosos parasitas; 3 necrose das células parasitadas; 4 granuloma epitelióide; 5 absorção da área necrosada (às vezes formando granuloma de corpo estranho; 6 infiltrado inespecífico crônico residual; e 7 cicatrização - que representaria a formação e a resolução das lesões. Discutiram-se também os prováveis mecanismos imunopatológicos que determinam esta seqüência de eventos e sua possível semelhança com a evolução das lesões na leishmaniose tegumentar humana.We have studied the histopathological aspects related to the evolution of cutaneous lesions experimentally produced in the monkey Cebus apella (Primates: Cebidae by Leishmania (V. lainsoni, L. (V. braziliensis and L. (L. amazonensis. Microscopical examination of a serie of biopsies obtained from these animals showed the kinetics of the cutaneous lesions regarding three species of Leishmania inoculated, as follows: 1 an initial non-specific chronic inflammatory infiltrate; 2 macrophagic nodules; 3 necrosis of parasitized phagocytic cells; 4 epithelioide granuloma; 5 absorption of the necrotic area (sometimes forming "foreign-body granuloma"; 6 a non-specific residual inflammatory infiltration; and 7 cicatrization. These pathological processes are, of course, responsible for both development and resolution of the leishmaniotic lesion. We also discuss some immunopathological mechanisms probably related with the sequencial events, and that could be also responsible for the different clinical aspects found in man.

Fernando T. Silveira

1990-12-01

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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  

Energy Technology Data Exchange (ETDEWEB)

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)

Lourenco, Cecilia de Oliveira

2000-07-01

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Leishmania (Leishmania) amazonensis infection in mice treated with FTY720.  

Science.gov (United States)

In transplantation, parasite diseases are transmitted from the donor, or appear as de novo infections, or activate from a dormant insource as a consequence of immunosuppression. Clinical findings have shown that an intact immune system is crucial to prevent recurrence of Leishmania infection. We used BALB/c and C57BL/6 mice to evaluate the role of FTY720 in leishmaniasis. Mice inoculated with Leishmania (Leishmania) amazonensis were followed over 7 weeks for foot thickness measurements after initiation of FTY720 treatment. After 10 days of treatment, spleen, blood, and the foot were harvested for evaluation. BALB/c showed greater evident foot thickness than C57BL/6 mice. Oral treatment with FTY720 (1 mg/kg/d) over 10 days produced the same outcome. Increases in CD4(+) and CD8(+) T cells were observed after infection; FTY720 treatment was associated with a decrease in CD4(+) T cells only in BALB/c mice, whereas CD8(+) T cells were decreased in both mice strains. CD11b(+) expression decreased after infection with a discrete increase after FTY720 treatment. Lymphopenia was observed among all FTY720-treated mice. In conclusion, we observed that FTY720 produced no worse an outcome as monotherapy in established infections with L (L) amazonensis. PMID:20304196

Lopes, C T; de Paula, D M B; Cury, P M; Valero-Lapchik, V B; Bueno, V

2010-03-01

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Activity of Cuban Plants Extracts against Leishmania amazonensis.  

Science.gov (United States)

Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Leishmania amazonensis. Furthermore, their toxicity was assayed against murine macrophage. The three most potent extracts against the amastigote stage of Leishmania amazonensis were from Hura crepitans, Bambusa vulgaris, and Simarouba glauca. PMID:22530133

García, Marley; Monzote, Lianet; Scull, Ramón; Herrera, Pedro

2012-01-01

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Miltefosine induces programmed cell death in Leishmania amazonensis promastigotes  

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Full Text Available In the current study, we evaluated the mechanism of action of miltefosine, which is the first effective and safe oral treatment for visceral leishmaniasis, in Leishmania amazonensis promastigotes. Miltefosine induced a process of programmed cell death, which was determined by the externalization of phosphatidylserine, the incorporation of propidium iodide, cell-cycle arrest at the sub-G0/G1 phase and DNA fragmentation into oligonucleosome-sized fragments. Despite the intrinsic variation that is detected in Leishmania spp, our results indicate that miltefosine causes apoptosis-like death in L. amazonensis promastigote cells using a similar process that is observed in Leishmania donovani.

Fernanda de Aquino Marinho

2011-06-01

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

OpenAIRE

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...

Real, Fernando; Vidal, Ramon Oliveira; Carazzolle, Marcelo Falsarella; Mondego, Jorge Mauri?cio Costa; Costa, Gustavo Gilson Lacerda; Herai, Roberto Hirochi; Wu?rtele, Martin; Carvalho, Lucas Miguel; E Ferreira, Renata Carmona; Mortara, Renato Arruda; Barbie?ri, Clara Lucia; Mieczkowski, Piotr; Da Silveira, Jose? Franco; Briones, Marcelo Ribeiro Da Silva; Pereira, Gonc?alo Amarante Guimara?es

2013-01-01

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Chronic infection by Leishmania amazonensis mediated through MAPK ERK mechanisms.  

Science.gov (United States)

Leishmania amazonensis is an intracellular protozoan parasite responsible for chronic cutaneous leishmaniasis (CL). CL is a neglected tropical disease responsible for infecting millions of people worldwide. L. amazonensis promotes alteration of various signaling pathways that are essential for host cell survival. Specifically, through parasite-mediated phosphorylation of extracellular signal regulated kinase (ERK), L. amazonensis inhibits cell-mediated parasite killing and promotes its own survival by co-opting multiple host cell functions. In this review, we highlight Leishmania-host cell signaling alterations focusing on those specific to (1) motor proteins, (2) prevention of NADPH subunit phosphorylation impairing reactive oxygen species production, and (3) localized endosomal signaling to up-regulate ERK phosphorylation. This review will focus upon mechanisms and possible explanations as to how Leishmania spp. evades the various layers of defense employed by the host immune response. PMID:24838145

Martinez, Pedro A; Petersen, Christine A

2014-08-01

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Morphologic aspects of the Leishmania amazonensis submitted to ionizing radiation  

International Nuclear Information System (INIS)

Leishmania amazonensis is a protozoan transmitted by a bite of a sandfly responsible for skin lesions in human and other mammalian hosts, being considered one of the most important endemic Public Health disease. Ionizing radiation shown to be an excellent method to kill these parasites, blocking their growth by nucleic acid (DNA) break, and stopping the respiratory metabolism. In this study, we analyze the effects of ionizing radiation on the morphology of the Leishmania amazonensis and the capacity of infection in experimental model. The radio sterilized parasites maintained their membrane surface preserved while destroyed the other proteins needed to their life, promoting the possible of a new antigenic model. (author)

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Miltefosine induces programmed cell death in Leishmania amazonensis promastigotes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In the current study, we evaluated the mechanism of action of miltefosine, which is the first effective and safe oral treatment for visceral leishmaniasis, in Leishmania amazonensis promastigotes. Miltefosine induced a process of programmed cell death, which was determined by the externalization of [...] phosphatidylserine, the incorporation of propidium iodide, cell-cycle arrest at the sub-G0/G1 phase and DNA fragmentation into oligonucleosome-sized fragments. Despite the intrinsic variation that is detected in Leishmania spp, our results indicate that miltefosine causes apoptosis-like death in L. amazonensis promastigote cells using a similar process that is observed in Leishmania donovani.

Fernanda de Aquino, Marinho; Keyla Cristiny da Silva, Gonçalves; Selma Soares de, Oliveira; Ana-Carolina de Siqueira Couto de, Oliveira; Maria, Bellio; Claudia Masini, d' Avila-Levy; André Luis Souza dos, Santos; Marta Helena, Branquinha.

2011-06-01

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Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In a previous work we demonstrated that diarylheptanoids extracted from Centrolobium sclerophyllum are very active against Leishmania amazonensis promastigotes. In order to continue our studies with these class of compounds, we decided to evaluate the activity of several diarylheptanoids derived fro [...] m curcumin (diferuloyl methane) against the extracellular form (promastigotes) of L. amazonensis. Furthermore, an experiment against the intracellular form of the parasite (amastigotes) was carried out, comparing the most active compound among the curcumin derivatives (the methylcurcumin) with des-O-methylcentrolobine, the most active diarylheptanoid derived from C. sclerophyllum.

Catarina AC, Araujo; Leila V, Alegrio; Denise CF, Gomes; Marco Edilson F, Lima; Leonardo, Gomes-Cardoso; Leonor L, Leon.

1999-11-01

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Leishmania amazonensis in dog with clinical diagnosis of visceral leishmaniasis in Paraná State, Brazil – a case reportLeishmania amazonensis em cão com quadro clínico de leishmaniose visceral no Estado do Paraná, Brasil – relato de caso  

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Full Text Available Leishmaniasis are antropozoonoses involving various species of Leishmania and hosts, with variable clinical presentations and considered of great importance to public health. This article describes a case of canine leishmaniasis caused by Leishmania amazonensis, from the town of Cambé, Paraná state, Brazil. This state is considered endemic for American cutaneous leishmaniasis (ACL in humans, but this is the first report in a dog in the region, caused by L. amazonensis. The taxonomic characterization of Leishmania was performed by multilocus enzyme electrophoresis technique (MLEE. Clinical signs were similar to those observed in visceral leishmaniasis as polyarthritis and progressive weight loss. It is concluded that the related polyarthritis when related to leishmaniasis, cannot be considered a clinical sign associated only with L. chagasi in view of the L. amazonensis also has this as one of its presentations. The LTA becomes a differential diagnosis of polyarthritis in dogs.As leishmanioses são antropozoonoses que envolvem diversas espécies de Leishmania e hospedeiros, tendo apresentações clínicas variáveis e consideradas de grande importância para a saúde pública. Este artigo descreve um caso de leishmaniose canina causada por Leishmania amazonensis, proveniente da cidade de Cambé, Paraná – Brasil. Este estado é considerado endêmico para a leishmaniose tegumentar americana (LTA em humanos, porém este é o primeiro relato em cão na região, provocado pela L. amazonensis. A caracterização taxonômica da Leishmania foi realizada através da técnica multilocus enzyme electrophoresis (MLEE. Os sinais clínicos foram similares aos observados na leishmaniose visceral como poliartrite e emagrecimento progressivo. Conclui-se que a poliartrite quando relacionada à leishmaniose não pode ser considerada um sinal clínico associado somente a L. chagasi, tendo em vista que a L. amazonensis também tem esta como uma das suas formas de apresentação. A LTA torna-se um diagnóstico diferencial de poliartrite em cães.

Patrícia Mendes Pereira

2012-02-01

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Leishmania amazonensis: characterization of an ecto-pyrophosphatase activity.  

Science.gov (United States)

Several ecto-enzymatic activities have been described in the plasma membrane of the protozoan Leishmania amazonensis, which is the major etiological agent of diffuse cutaneous leishmaniasis in South America. These enzymes, including ecto-phosphatases, contribute to the survival of the parasite by participating in phosphate metabolism. This work identifies and characterizes the extracellular hydrolysis of inorganic pyrophosphate related to an ecto-pyrophosphatase activity of the promastigote form of L. amazonensis. This ecto-pyrophosphatase activity is insensitive to MnCl2 but is strongly stimulated by MgCl2. This stimulation was not observed during the hydrolysis of p-nitrophenyl phosphate (p-NPP) or ?-glycerophosphate, two substrates for different ecto-phosphatases present in the L. amazonensis plasma membrane. Furthermore, extracellular PPi hydrolysis is more efficient at alkaline pHs, while p-NPP hydrolysis occurs mainly at acidic pHs. These results led us to conclude that extracellular PPi is hydrolyzed not by non-specific ecto-phosphatases but rather by a genuine ecto-pyrophosphatase. In the presence of 5mM MgCl2, the ecto-pyrophosphatase activity from L. amazonensis is sensitive to micromolar concentrations of NaF and millimolar concentrations of CaCl2. Moreover, this activity is significantly higher during the first days of L. amazonensis culture, which suggests a possible role for this enzyme in parasite growth. PMID:24316462

Freitas-Mesquita, Anita Leocadio; Fonseca-de-Souza, André Luiz; Meyer-Fernandes, José Roberto

2014-02-01

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The genome sequence of Leishmania (Leishmania) amazonensis: functional annotation and extended analysis of gene models.  

Science.gov (United States)

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

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; Carmona e Ferreira, Renata; Mortara, Renato Arruda; Barbiéri, Clara Lucia; Mieczkowski, Piotr; da Silveira, José Franco; Briones, Marcelo Ribeiro da Silva; Pereira, Gonçalo Amarante Guimarães; Bahia, Diana

2013-12-01

22

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation  

International Nuclear Information System (INIS)

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 60Co 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 amation of metacyclic forms of Leishmania amazonensis in culture. (author)

23

Metaciclogénesis y desarrollo de Leishmania (Leishmania) amazonensis (Kinetoplastida: Trypanosomatidae) en Lutzomyia ovallesi (Diptera: Psychodidae) / Metacyclogenesis and development of Leishmania (Leishmania) amazonensis (Kinetoplastida: Trypanosomatidae) in Lutzomyia ovallesi (Diptera: Psychodidae)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish La interacción Leishmania-vector es un proceso complejo y multifactorial. En los últimos años se han logrado avances importantes en la relación Leishmania-vector, pero aún se desconocen algunos aspectos. Este trabajo estudia la interacción de Leishmania (Leishmania) amazonensis (Kinetoplastida: Tryp [...] anosomadidae) en Lutzomyia ovallesi (Diptera: Psychodidae). Hembras de L. ovallesi fueron infectadas artificialmente y se determinó el patrón de desarrollo, densidad parasitaria, secuencia de morfotipos de promastigotes en las regiones del intestino, efecto de la realimentación, y el patrón de carbohidratos de la superficie de las leptomonas usando lectinas fluorescentes. Los resultados mostraron desarrollo suprapilórico de L. (L.) amazonensis. La densidad parasitaria mostró dos ciclos de división separados en tiempo y espacio, se observaron morfotipos caracterizados como paramastigotes en división. La realimentación no alteró la migración de los morfotipos y la mayor proporción de leptomonas en el intestino medio torácico sugiere migración natural que pudiera ser modulada por el gradiente de carbohidratos en el intestino del flebótomo y por la exposición de saliva. Las leptomonas exhibieron diferentes patrones de unión de glicoconjugados, que sugieren presencia de distintos residuos de carbohidratos en la superficie celular del parásito y/o flagelo, que pueden tener funciones importantes en la interacción y estabilidad de los parásitos en el lumen del intestino y su migración a las diferentes regiones del mismo. Se aportan diferentes aspectos del desarrollo de L. (L.) amazonensis en L. ovallesi importantes para entender su potencial vectorial Abstract in english Leishmania-vector interaction is a complex and multifactorial process. During the last few years important advances in the Leishmania-vector interaction have been reached but there still some unknown aspects. This work studies the Leishmania (Leishmania) amazonensis (Kinetoplastide: Trypanosomatidae [...] ) interaction in Lutzomia ovallesi (Diptera: Psychodidae). L. ovallesi females were artificially infected and the development pattern, parasite density, and promastigote morphotype sequence in the intestinal regions were determined, as well as the effect of re-feeding, and the carbohydrate pattern of the leptomonad surface using fluorescent lectins. The results showed suprapiloric development of L. (L.)amazonensis. Parasite density showed two division cycles separated in time and space, morphotypes characterized as dividing paramastigotes were observed. Re-feeding did not alter the migration of morphotypes and the greater proportion of leptomonads in the middle intestine suggests a natural migration which could be modulated by the carbohydrate gradient in the phlebotom intestine and by exposure to saliva. Leptomonads exhibited different glyconjugate union patterns which suggest the presence of various carbohydrate residues in the cell surface of the parasite and/or flagellum, which can have important functions in the interaction and stability of the parasites in the intestinal lumen and their migration to the different intestinal regions. Several aspects of L. (L.)amazonensis development in L. ovallesi important for understanding its vectorial potency are discussed

Elsa, Nieves; Maritza, Rondón.

2010-12-01

24

Comparative two-dimensional gel electrophoresis maps for promastigotes of Leishmania amazonensis and Leishmania major  

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Full Text Available SciELO Brazil | Language: English Abstract in english The outcome of Leishmania infections is determined by both the parasite species and the host genetic makeup. While much has been learned regarding immune responses to this parasite, our knowledge on parasite-derived factors is limited. The recent completion of the L. major and L. infantum genome seq [...] uence projects and concurrent advancement in proteomics technology would greatly accelerate the search for novel Leishmania proteins. Using a proteomics-based approach to study species-specific Leishmania proteins, we developed high-resolution, broad pH (3-10) two-dimensional gel electrophoresis (2-DE) separations to determine protein-expression profiles between highly infectious forms of the parasitic species L. amazonensis (New World) and L. major (Old World). Approximately 1,650 and 1,530 distinct protein spots were detected in the L. amazonensis and L. major gels, respectively. While a vast majority of the spots had similar distribution and intensity, a few were computationally defined as preferentially expressed in L. amazonensis in comparison to L. major, or vice versa. These data attest to the feasibility of establishing a 2-DE-based protein array for inter-species profiling of Leishmania proteins and provide the framework for future design of proteome studies of Leishmania.

Reynolds K. B., Brobey; Fang C., Mei; Xiaodong, Cheng; Lynn, Soong.

2006-02-01

25

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation  

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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.

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

26

Development of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the sand fly Lutzomyia migonei (Diptera: Psychodidae).  

Science.gov (United States)

Development of Leishmania braziliensis (Vianna) and Leishmania amazonensis (Lainson and Shaw) in the sand fly Lutzomyia migonei (França) was compared by studying the parasite microhabitats in the alimentary tract, the sequence of parasite morphological changes leading to the metacyclogenesis process, and the parasite transmission to the vertebrate susceptible host. Although the infections by the 2 Leishmania species were initiated with the same number of amastigotes, Le. amazonensis developed a higher population. Infections with Le. braziliensis were typically peripylarian and those with Le. amazonensis suprapylarian but with an unusual invasion of an organ other than the gut, the Malpighian tubules. The life cycle of the 2 parasites within the sand fly vector included the development of all promastigote forms: procyclics, haptomonads, nectomonads, paramastigotes and infective metacyclics, the last of which are uniquely adapted for transmission to the vertebrate hosts. Appearance of metacyclics coincided with the presence of large number of procyclics and haptomonads, low numbers of nectomonads and the appearance of paramastigotes. In both type of infections, there was a high mortality of the promastigotes inside the bloodmeal during digestion but once infection became established metacyclic forms appeared. Although the numbers of metacyclics that developed in sand flies were low for both parasites they were able to transmit the infection to vertebrates, a key event in the vector competence. We suggest that L. migonei is a true biological host and a possible vector of the 2 Leishmania species, which coexist in extensive geographic areas. PMID:15218917

Nieves, E; Pimenta, P F

2000-01-01

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Desarrollo de Leishmania mexicana y Leishmania amazonensis en Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine Development of Leishmania mexicana and Leishmania amazonensis in Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine  

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Full Text Available El objetivo de este trabajo consistió en estudiar los cambios morfológicos que ocurren durante el desarrollo de Leishmania mexicana (MHOM/VE/72/AZV y Le. amazonensis (IFLA/BR/67/PI18 en Lutzomyia euansi. Hembras de Lu. evansi se alimentaron a partir de una lesión tarsal de hámster y se examinaron en busca de infección cada 24 h hasta las 168 h posalimentación. El patrón de desarrollo de Le. mexicana y Le. amazonensis en Lu. euansi fue de tipo suprapilórico, de acuerdo con lo descrito para las especies del complejo Le. mexicana. La transformación de formas amastigotas a procíclicos ocurrió para ambas especies entre las 24 - 48 h postinfección. Los parásitos mostraron su adaptación al microambiente del tracto digestivo de Lu. euansi y desarrollo hacia formas maduras: nectomonas, haptomonas y paramastigotas. La forma paramastigota se observó, en bajo porcentaje, a las 120 h postingesta infectiva en ambas especies. La disminución temprana de nutrientes en Lu. euansi, debido al rápido proceso de digestión de sangre (3 a 4 días, pudiera explicar el bajo porcentaje de desarrollo alcanzado hacia las formas paramastigotas y la ausencia de formas metacíclicas en este modelo.The aim of this paper was to study the morphological changes in the development of Leishmania mexicana (MMOM/VE/72/AZV and L. amazonensis (IFLA/BR/67/PI18 in Lutzomyia euansi. Pernales of Lu. euansi fed on a hámster tarsal lesión and were examined for infection at 24 h intervals from 24 h to 168 h post- feeding. The pattern of development of Le. mexicana and Le. amazonensis in Lu. euansi was suprapylarian consistentwith what has been described forspecies of the Le. mexicana complex. Transformaron from amastigote to procyclical forms occurred in both species at 24 - 48 h post-infection. The parasites showed their adaptaüon lo the gut environment of Lu. euansi and development to mature forms: nectomonads, haptomonads and pararnastigotes. The paramastigote form was observed in low percentage at 120 h post-infected ingestión in both species. The early depletion of nutrients in Lu. euansi, due to a faster rate of digestión (3 to 4 days, could explain the low percentage of development reaching the paramastigote forms and the absence of the metacyclical forms in this model.

MARÍA ALEJANDRA VIVENES

2005-06-01

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Desarrollo de Leishmania mexicana y Leishmania amazonensis en Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine) / Development of Leishmania mexicana and Leishmania amazonensis in Lutzomyia evansi (Díptera: Psychodidae, Phlebotomine)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish El objetivo de este trabajo consistió en estudiar los cambios morfológicos que ocurren durante el desarrollo de Leishmania mexicana (MHOM/VE/72/AZV) y Le. amazonensis (IFLA/BR/67/PI18) en Lutzomyia euansi. Hembras de Lu. evansi se alimentaron a partir de una lesión tarsal de hámster y se examinaron [...] en busca de infección cada 24 h hasta las 168 h posalimentación. El patrón de desarrollo de Le. mexicana y Le. amazonensis en Lu. euansi fue de tipo suprapilórico, de acuerdo con lo descrito para las especies del complejo Le. mexicana. La transformación de formas amastigotas a procíclicos ocurrió para ambas especies entre las 24 - 48 h postinfección. Los parásitos mostraron su adaptación al microambiente del tracto digestivo de Lu. euansi y desarrollo hacia formas maduras: nectomonas, haptomonas y paramastigotas. La forma paramastigota se observó, en bajo porcentaje, a las 120 h postingesta infectiva en ambas especies. La disminución temprana de nutrientes en Lu. euansi, debido al rápido proceso de digestión de sangre (3 a 4 días), pudiera explicar el bajo porcentaje de desarrollo alcanzado hacia las formas paramastigotas y la ausencia de formas metacíclicas en este modelo. Abstract in english The aim of this paper was to study the morphological changes in the development of Leishmania mexicana (MMOM/VE/72/AZV) and L. amazonensis (IFLA/BR/67/PI18) in Lutzomyia euansi. Pernales of Lu. euansi fed on a hámster tarsal lesión and were examined for infection at 24 h intervals from 24 h to 168 h [...] post- feeding. The pattern of development of Le. mexicana and Le. amazonensis in Lu. euansi was suprapylarian consistentwith what has been described forspecies of the Le. mexicana complex. Transformaron from amastigote to procyclical forms occurred in both species at 24 - 48 h post-infection. The parasites showed their adaptaüon lo the gut environment of Lu. euansi and development to mature forms: nectomonads, haptomonads and pararnastigotes. The paramastigote form was observed in low percentage at 120 h post-infected ingestión in both species. The early depletion of nutrients in Lu. euansi, due to a faster rate of digestión (3 to 4 days), could explain the low percentage of development reaching the paramastigote forms and the absence of the metacyclical forms in this model.

MARÍA ALEJANDRA, VIVENES; MILAGROS, OVIEDO; JULIO CÉSAR, MÁRQUEZ.

2005-06-01

29

A dhfr-ts- Leishmania major Knockout Mutant Cross-protects against Leishmania amazonensis  

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Full Text Available E10-5A3 is a dhfr-ts- Leishmania major double knockout auxotrophic shown previously to induce substantial protection against virulent L. major infection in both genetically susceptible and resistant mice. We investigated the capacity of dhfr-ts- to protect against heterologous infection by L. amazonensis. The degree of protection was evaluated by immunization of BALB/c or C57BL/6 mice with E10-5A3, followed by L. amazonensis challenge. Whether immunized by subcutaneous (SC or intravenous (IV inoculation, susceptible and resistant mice displayed a partial degree of protection against challenge with virulent L. amazonensis. SC-immunized BALB/c mice developed lesions 40 to 65% smaller than non immunized mice, while IV immunization led to protection ranging from 40 to 75% in four out of six experiments compared to non immunized animals. The resistant C57BL/6 mice displayed comparable degrees of protection, 57% by SC and 49% by IV immunization. Results are encouraging as it has been previously difficult to obtain protection by SC vaccination against Leishmania, the preferred route for human immunization.

Veras PST

1999-01-01

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

International Nuclear Information System (INIS)

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

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Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote  

OpenAIRE

The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purifi...

Marcos Hikari Toyama; Wladimir Ronald Lobo Farias; Daniela de Oliveira Toyama; Henrique Hessel Gaeta; Camila Lehnhardt Pires; Selma Dzimidas Rodrigues; Daniel Bristot

2013-01-01

32

A dhfr-ts- Leishmania major Knockout Mutant Cross-protects against Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english E10-5A3 is a dhfr-ts- Leishmania major double knockout auxotrophic shown previously to induce substantial protection against virulent L. major infection in both genetically susceptible and resistant mice. We investigated the capacity of dhfr-ts- to protect against heterologous infection by L. amazon [...] ensis. The degree of protection was evaluated by immunization of BALB/c or C57BL/6 mice with E10-5A3, followed by L. amazonensis challenge. Whether immunized by subcutaneous (SC) or intravenous (IV) inoculation, susceptible and resistant mice displayed a partial degree of protection against challenge with virulent L. amazonensis. SC-immunized BALB/c mice developed lesions 40 to 65% smaller than non immunized mice, while IV immunization led to protection ranging from 40 to 75% in four out of six experiments compared to non immunized animals. The resistant C57BL/6 mice displayed comparable degrees of protection, 57% by SC and 49% by IV immunization. Results are encouraging as it has been previously difficult to obtain protection by SC vaccination against Leishmania, the preferred route for human immunization.

PST, Veras; CI, Brodskyn; FMP, Balestieri; LAR de, Freitas; APS, Ramos; ARP, Queiroz; A, Barral; SM, Beverley; M, Barral-Netto.

1999-07-01

33

Molecular diagnosis of Leishmania amazonensis in a captive spider monkey in Bauru, São Paulo, Brazil.  

Science.gov (United States)

The municipality of Bauru, São Paulo, Brazil, is an area endemic for leishmaniasis. At the zoo, a spider monkey (Ateles paniscus) showed nonpathognomonic symptoms, such as weight loss and pale mucous membranes. Blood was collected from the jugular vein and investigated for the presence of Leishmania spp. DNA by polymerase chain reaction and restriction fragment length polymorphism. Parasite DNA was detected, and the pattern observed was identical to Leishmania amazonensis. This study presents molecular evidence of L. amazonensis infection in a captive spider monkey. PMID:23272368

Lima, Valéria Marçal Felix de; Santiago, Maria Emília Bodini; Sanches, Leticia da Cruz; Lima, Beatriz Dolabela de

2012-12-01

34

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 d [...] o 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: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local. Abstract in english 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. M [...] ETHODS: 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.

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

2010-10-01

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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  

Directory of Open Access Journals (Sweden)

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: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local.

Maria Elizabeth Cavalheiros Dorval

2010-10-01

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Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva  

Scientific Electronic Library Online (English)

Full Text Available Leishmania parasites expose phosphatidylserine (PS) on their surface, a process that has been associated with regulation of host's immune responses. In this study we demonstrate that PS exposure by metacyclic promastigotes of Leishmania amazonensis favours blood coagulation. L. amazonensis accelera [...] tes in vitro coagulation of human plasma. In addition, L. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. This process was reversed by annexin V which blocks PS binding sites. During blood meal, Lutzomyia longipalpis sandfly inject saliva in the bite site, which has a series of pharmacologically active compounds that inhibit blood coagulation. Since saliva and parasites are co-injected in the host during natural transmission, we evaluated the anticoagulant properties of sandfly saliva in counteracting the procoagulant activity of L. amazonensis . Lu. longipalpis saliva reverses plasma clotting promoted by promastigotes. It also inhibits thrombin formation by the prothrombinase complex assembled either in phosphatidylcholine (PC)/PS vesicles or in L. amazonensis . Sandfly saliva inhibits factor X activation by the intrinsic tenase complex assembled on PC/PS vesicles and blocks factor Xa catalytic activity. Altogether our results show that metacyclic promastigotes of L. amazonensis are procoagulant due to PS exposure. Notably, this effect is efficiently counteracted by sandfly saliva.

Natalia Cadaxo, Rochael; Luize Goncalves, Lima; Sandra Maria Pereira de, Oliveira; Marcello Andre, Barcinski; Elvira Maria, Saraiva; Robson Queiroz, Monteiro; Lucia Helena, Pinto-da-Silva.

2013-09-01

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A putative role for inosine 5' monophosphate dehydrogenase (IMPDH) in Leishmania amazonensis programmed cell death.  

Science.gov (United States)

Leishmania amazonensis undergoes apoptosis-like programmed cell death (PCD) under heat shock conditions. We identified a potential role for inosine 5' monophosphate dehydrogenase (IMPDH) in L.?amazonensis PCD. Trypanosomatids do not have a "de novo" purine synthesis pathway, relying on the salvage pathway for survival. IMPDH, a key enzyme in the purine nucleotide pathway, is related to cell growth and apoptosis. Since guanine nucleotide depletion triggers cell cycle arrest and apoptosis in several organisms we analyzed the correlation between IMPDH and apoptosis-like death in L.?amazonensis. The L.?amazonensis IMPDH inhibition effect on PCD was evaluated through gene expression analysis, mitochondrial depolarization and detection of Annexin-V labeled parasites. We demonstrated a down-regulation of impdh expression under heat shock treatment, which mimics the natural mammalian host infection. Also, IMPDH inhibitors ribavirin and mycophenolic acid (MPA) prevented cell growth and generated an apoptosis-like phenotype in sub-populations of L.?amazonensis promastigotes. Our results are in accordance with previous results showing that a subpopulation of parasites undergoes apoptosis-like cell death in the nutrient poor environment of the vector gut. Here, we suggest the involvement of purine metabolism in previously observed apoptosis-like cell death during Leishmania infection. PMID:25499513

Pitaluga, A N; Moreira, M E C; Traub-Csekö, Y M

2015-02-01

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Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania) amazonensis. A comparative study between mefloquine and aminosidine / Ensaio terapêutico na leishmaniose tegumentar experimental causada por Leishmania (Leishmania) amazonensis. Um estudo comparativo entre mefloquina e aminosidine  

Scientific Electronic Library Online (English)

Full Text Available Foram utilizados 182 camundongos machos, isogênicos, da linhagem C57BL/6 inoculados na orelha direita com 3,0 x 10(6) formas promastigotas da cepa MHOM/BR/PH8 de Leishmania (Leishmania) amazonensis. Os animais foram separados em três grupos: 1) 52 animais tratados com mefloquina (16mg/kg/dia/10 dias [...] ), 2) 52 animais tratados com aminosidina [Paramomicina ®] (20mg/kg/dia/20 dias), 3) 78 animais controles, não manipulados. Vinte e seis animais de cada grupo tratado foram sacrificados nove e quinze semanas após a inoculação. Animais do grupo controle foram sacrificados na sexta, nona e décima quinta semanas após a inoculação. Ao final do tratamento, em relação à curva de peso da orelhas, somente nos animais tratados com aminosidina, houve nítida redução do peso em comparação com grupo controle. Na histopatologia verificou-se: a) não houve diferença entre o grupo tratado com mefloquina e o grupo controle; o grupo tratado com aminosidina, ao final do tratamento, teve menor infiltração por macrófagos vacuolizados; b) as avaliações da extensão das áreas de necrose e do nível da fibrose tecidual não mostraram diferenças entre os grupos tratados. Os animais do grupo controle apresentaram fibrose mais acentuada, seis semanas após o fim do tratamento. Pode-se concluir que ocorreu efeito terapêutico reduzido com a mefloquina e houve significativa melhora com a aminosidina. Entretanto, em todos os grupos as lesões não chegaram a curar. Abstract in english One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 106 Leishmania (Leishmania) amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1) oral mefloquine hydrochloride treatment (1 [...] 6mg/kg/day/10 days), 2) intramuscular aminosidine (Paromomycin®) treatment (20mg/kg/20 days) and 3) control. Twenty six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation), and one six weeks later (fifteen weeks after inoculation). Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine) and Group 3 (control) subjects. Group 2 animals (aminosidine) presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a) there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment). b) both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.

Letícia Oba, Galvão; Sebastião, Moreira Júnior; Pedro, Medeiros Júnior; Gleiser José Piantino, Lemos; Nara Fabiana, Cunha; Rosa Maria Parreiras, Antonino; Bráulio Silva, Santos Filho; Albino Verçosa, Magalhães.

2000-08-01

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Histopathological studies of visceralized Leishmania (Leishmania) amazonensis in mice experimentally infected.  

Science.gov (United States)

BALB/c, C57BL/6, and DBA/2 mice were subcutaneously infected in the left footpad by injecting 10(4) Leishmania (Leishmania) amazonensis amastigotes. Mice were sacrificed 20, 30, 40, 60 and 90 days post-infection. Fragments of liver, kidney, spleen, skin, and draining lymph node were collected for histological examination. Light microscopy showed that at 20 days after infection BALB/c mice presented discrete inflammatory infiltrates in the skin made up of eosinophils, lymphocytes, and rare parasitized macrophages. Ninety days post-infection, the dermis showed necrotic tissue, large numbers of mononuclear cells and vacuolated macrophages filled with amastigotes. Forty days post-infection, the draining lymph nodes showed hyperplastic germinal centers, increase of high endothelial venules and apoptosis in germinal center cells. After the first 3 months post-infection, the involvement of spleen, kidney and liver was discreet, being characterized by multifocal inflammatory infiltrates. Eight months after infection, the animals presented metastatic lesions in the contralateral footpad and nose. In deep dermis, there was remarkable proliferation of fibroblasts associated with collagen fibers. The liver showed multifocal granulomas and mononuclear infiltrate around the blood vessels, but no parasites were observed, except in one animal. In some mice there were immature cells of the hematopoietic lineage. Both BALB/c and C57BL/6 mice presented osteonecrosis, which is characterized by pycnotic osteocytes and empty lacunae at the point of inoculation and subsequently, replacement of this tissue by fibrous connective tissue and colonization of the bone marrow. A diffuse inflammatory process composed of mononuclear cells and rare parasites were seen in the kidneys. In one mouse, bone marrow cells were observed in the renal medulla along with where free amastigotes. DBA/2 mice developed a mild infection and they did not visceralize. In conclusion, our data demonstrates that in susceptible mice L. (L.) amazonensis, a causative agent of tegumentary leishmaniasis, causes pathological changes similar to those produced by Leishmania (L.) infantum in both humans and canids. PMID:15135858

Abreu-Silva, A L; Calabrese, K S; Cupolilo, S M N; Cardoso, F O; Souza, C S F; Gonçalves da Costa, S C

2004-05-26

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Reductions in Skin and Systemic Parasite Burdens as a Combined Effect of Topical Paromomycin and Oral Miltefosine Treatment of Mice Experimentally Infected with Leishmania (Leishmania) amazonensis?  

OpenAIRE

This study aimed to investigate the activity of a combination of topical paromomycin gel and oral miltefosine for the treatment of experimental cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis. The efficacy of the combination, evaluated by measuring lesion size and parasite burden in the skin and spleen, was assessed in BALB/c mice infected by L. (L.) amazonensis. The miltefosine was administered orally at 10 mg/kg of body weight/day for 10 days, while 10% paromomycin gel...

Aguiar, Marta Gontijo; Pereira, Aline Ma?rcia Machado; Fernandes, Ana Paula; Ferreira, Lucas Antonio Miranda

2010-01-01

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Immune responses induced by a Leishmania (Leishmania) amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A resposta imune induzida por uma proteína recombinante de Leishmania (Leishmania) amazonensis de 33 kD (Larp33) foi avaliada em linfócitos de indivíduos vacinados com a Leishvacin® e em camundongos através de vacinação. Larp33 foi expressa em Escherichia coli após clonagem de um fragmento genômico [...] de L. (L.) amazonensis de 2,2 kb no vetor pDS56-6His. Larp33 foi reconhecida por anticorpos IgG presentes no soro de indivíduos vacinados com Leishvacin® e induziu proliferação em linfócitos desses indivíduos em níveis comparáveis ao antígeno total de Leishmania. A análise por imunoblot indicou que Larp33 corresponde a uma proteína de aproximadamente 40 kD expressa em promastigotas de L. (L.) amazonensis e L. (Viannia) braziliensis. Hibridização com sonda de DNA correspondente a parte do fragmento clonado, também demonstrou que o gene codificador desta proteína é expresso em promastigotas destas duas espécies. Larp33 em associação com BCG (Bacille Calmette-Guerin) foi capaz de induzir 75% de proteção em camundongos C75BL/10 e BALB/c, suceptíveis à infecção por L. (L.) amazonensis. Linfócitos dos camundongos protegidos produziram IL-2 e IFN-g em resposta a Larp33. Nossos resultados indicam que Larp33 é imunogênica para linfócitos de indivíduos vacinados com Leishvacin ® e protetora para camundongos contra a infecção por L. (L.) amazonensis Abstract in english In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is recognized by antibodies and peripheral blood leukocytes (PBL) from subjects va [...] ccinated with Leishvacin ®, Larp33 was expressed in Escherichia coli after cloning of a 2,2 kb Sau3A digested genomic fragment of L. (L.) amazonensis into the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33 corresponds to an approximately 40-kD native protein expressed in promastigotes of L.(L.) amazonensis and L. (Viannia) braziliensis. Northern blots of total RNA also demonstrated that the gene coding for this protein is expressed in promastigotes of the major lineages of Leishmania causing American Cutaneous Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains (BALB/c and C57BL/10) against L. (L.) amazonensis after vaccination using Bacille Calmette-Guerin (BCG) as adjuvant. In vitro stimulation of splenocytes from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and IFN-g, suggesting that a Th1 cell-mediated protective response is associated with the resistance observed in these mice. As revealed by its immunogenic and antigenic properties, this novel recombinant antigen is a suitable candidate to compose a vaccine against cutaneous leishmaniasis

Ana Paula, FERNANDES; Elizabeth, Cortez HERRERA; Wilson, MAYRINK; Ricardo, T. GAZZINELLI; Wen Yu, LIU; Carlos Alberto da, COSTA; Carlos Alberto Pereira, TAVARES; Maria Norma, MELO; Marilene Susan Marques, MICHALICK; Reiner, GENTZ; Evaldo, NASCIMENTO.

1997-03-01

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Cross-Protective Immunity to Leishmania amazonensis is Mediated by CD4+ and CD8+ Epitopes of Leishmania donovani Nucleoside Hydrolase Terminal Domains  

OpenAIRE

The nucleoside hydrolase (NH) 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...

Nico, Dirlei; Gomes, Daniele Crespo; Alves-silva, Marcus Vini?cius; Freitas, Elisangela Oliveira; Morrot, Alexandre; Bahia, Diana; Palatnik, Marcos; Rodrigues, Mauricio M.; Palatnik-de-sousa, Clarisa B.

2014-01-01

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

OpenAIRE

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 ?g/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 ...

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

1999-01-01

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Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages  

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Full Text Available In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11 expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL-10 secretion and arginase activity while reducing nitric oxide (NO production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Daniel Ignacchiti Lacerda

2012-03-01

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

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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.

GIORGIO Selma

1998-01-01

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Identificação de espécies de Leishmania isoladas de casos humanos em Mato Grosso do Sul por meio da reação em cadeia da polimerase / Identification of Leishmania species isolated in human cases in Mato Grosso do Sul, by means of the polymerase chain reaction  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese As leishmanioses são zoonoses endêmicas em Mato Grosso do Sul e têm por agentes etiológicos nessa região Leishmania (Leishmania) chagasi, Leishmania (Leishmania) amazonensis e Leishmania (Viannia) braziliensis. Como método para identificação de espécies de Leishmania, a reação em cadeia da polimeras [...] e é uma ferramenta com elevada especificidade e sensibilidade. Analisaram-se 39 isolados de Leishmania criopreservados, obtidos por meio de aspirado medular e/ou biópsia de lesão, conforme a suspeita clínica. Os isolados foram submetidos à extração de DNA e à reação em cadeia da polimerase com os iniciadores: RV1/RV2 para Leishmania (Leishmania) chagasi, a1/a2 para a identificação de Leishmania (Leishmania) amazonensis e b1/b2 para Leishmania (Viannia) braziliensis. Leishmania (Leishmania) chagasi foi a única espécie identificada em 37 casos de leishmaniose visceral. Leishmania (Leishmania) amazonensis foi identificada em dois isolados de pacientes com diagnóstico de leishmaniose tegumentar. Os resultados obtidos confirmam a possibilidade do uso dos três pares de iniciadores como uma ferramenta na caracterização de isolados de Leishmania. Abstract in english Leishmaniases are endemic zoonoses in the State of Mato Grosso do Sul. Their etiological agents in this region of Brazil are Leishmania (Leishmania) chagasi, Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis. The polymerase chain reaction (PCR) is a tool with high specificity [...] and sensitivity for identifying Leishmania species. This study examined 39 cryopreserved isolates of Leishmania that had been collected by bone marrow aspiration and/or lesion biopsy, depending on the clinical suspicion. The isolates were subjected to DNA extraction and PCR using the following primers: RV1/RV2 for identifying Leishmania (Leishmania) chagasi, a1/a2 for Leishmania (Leishmania) amazonensis and b1/b2 for Leishmania (Viannia) braziliensis.Leishmania (Leishmania) chagasi was the only species identified in the 37 cases of visceral leishmaniasis.Leishmania (Leishmania) amazonensis was identified in two isolates from patients with a diagnosis of cutaneous leishmaniasis. The results obtained confirm that it is possible to use these three pairs of primers as a tool for characterizing Leishmania isolates.

Manoel Sebastião da Costa, Lima Junior; Renato, Andreotti; Maria Elizabeth Moraes Cavalheiros, Dorval; Elisa Teruya, Oshiro; Alessandra Gutierrez de, Oliveira; Maria de Fatima Cepa, Matos.

2009-06-01

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CrATP interferes in the promastigote-macrophage interaction in Leishmania amazonensis infection.  

Science.gov (United States)

Recent have shown the relationship between Ecto-Nucleoside-Triphosphate-Diphosphohydrolases (Ecto-NTPDases or ecto-nucleotidases) and virulence and infectivity in trypanosomatids. In this work, the inhibition of the ecto-ATPase activities and promastigote growth of Leishmania amazonensis by CrATP was characterized. Furthermore, this compound was used to investigate the role of ecto-nucleotidase in the interaction of L. amazonensis with resident peritoneal macrophages obtained from BALB/c mice. CrATP partially inhibits the ecto-ATPase activity, presenting Ki values of 575·7±199·1 and 383·5±79·0 ?m, in the presence or absence of 5 mm MgCl2, respectively. The apparent Kms for ATP (2·9±0·5 mm to Mg2+-dependent ecto-ATPase and 0·4±0·2 mm to Mg2+-independent ecto-ATPase activities) are not significantly altered by CrATP, suggesting a reversible non-competitive inhibition of both enzymes. When CrATP was added to the cultivation medium at 500 ?m, it drastically inhibited the cellular growth. The interaction of promastigote forms of L. amazonensis with BALB/c peritoneal macrophages is strongly affected by CrATP. When the parasites were treated with 500 ?m CrATP before interacting with macrophages, the adhesion and endocytic indices were strongly reduced to 53·0±14·8% and 39·8±1·1%, respectively. These results indicate that ecto-nucleotidase plays an important role in the infection process caused by Leishmania amazonensis. PMID:21679488

Ennes-Vidal, V; Castro, R O S; Britto, C; Barrabin, H; D'Avila-Levy, C M; Moreira, O C

2011-07-01

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In Vitro Metacyclogenesis of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis Clinical Field Isolates, as Evaluated by Morphology, Complement Resistance, and Infectivity to Human Macrophages  

Science.gov (United States)

This study was designed to assess in vitro metacyclogenesis of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis clinical field isolates obtained from patient lesions (L. braziliensis IMG3 and PPS6m; L. amazonensis MAB6). Metacyclogenesis was evaluated by different criteria, namely, promastigote size (morphometric analysis and flow cytometry), surface modifications (loss of lectin or monoclonal antibody (mAb) binding, complement resistance), and infectivity to human macrophages. Growth curves were similar for all parasites evaluated. The various features analyzed were expressed in a high percentage of promastigotes at 6th and 10th days of culture and a low percentage at the 2nd day. However, in most isolates, these features, considered as markers of metacyclogenesis, seemed to develop with different time courses, since the percentages of metacyclic forms detected with each technique were usually different. Parasites from 6th or 10th day and those negatively selected with lectin or mAb similarly infected human macrophages. From all isolates analyzed, L. amazonensis PH8 and MAB6 showed the highest and the lowest levels of susceptibility, respectively, to leishmanicidal activity of IFN-?/LPS-activated macrophages. Our results showed that by using different techniques to evaluate different aspects of metacyclogenesis (morphological and biochemical modifications) different percentages of metacyclic promastigotes can be detected in each isolate culture. PMID:25695070

da Silva, Ildefonso Alves; Morato, Camila Imai; Quixabeira, Valéria Bernadete Leite; Pereira, Ledice Inácia de Araújo; Dorta, Miriam Leandro; de Oliveira, Milton Adriano Pelli; Horta, Maria Fátima; Ribeiro-Dias, Fátima

2015-01-01

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IL-27 enhances Leishmania amazonensis infection via ds-RNA dependent kinase (PKR) and IL-10 signaling.  

Science.gov (United States)

The protozoan parasite Leishmania infects and replicates in macrophages, causing a spectrum of diseases in the human host, varying from cutaneous to visceral clinical forms. It is known that cytokines modulate the immunological response against Leishmania and are relevant for infection resolution. Here, we report that Interleukin (IL)-27 increases Leishmania amazonensis replication in human and murine macrophages and that the blockage of the IL-10 receptor on the surface of infected cells abolished the IL-27-mediated enhancement of Leishmania growth. IL-27 induced the activation/phosphorylation of protein kinase R (PKR) in macrophages, and PKR blockage or PKR gene deletion abrogated the enhancement of the parasite growth driven by IL-27, as well as the L. amazonensis-induced macrophage production of IL-27. We also observed that L. amazonensis-induced expression of IL-27 depends on type I interferon signaling and the engagement of Toll-like receptor 2. Treatment of Leishmania-infected mice with IL-27 increased lesion size and parasite loads in the footpad and lymph nodes of infected animals, indicating that this cytokine exerts a local and a systemic effect on parasite growth and propagation. In conclusion, we show that IL-27 is a L. amazonensis-enhancing factor and that the PKR/IFN1 axis and IL-10 are critical mediators of this IL-27 induced effect. PMID:25466588

Barreto-de-Souza, Victor; Ferreira, Pedro L C; de Carvalho Vivarini, Aislan; Calegari-Silva, Teresa; Soares, Deivid Costa; Regis, Eduardo G; Pereira, Renata M S; Silva, Aristóbolo M; Saraiva, Elvira M; Lopes, Ulisses G; Bou-Habib, Dumith Chequer

2015-04-01

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

International Nuclear Information System (INIS)

Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m (99mTc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of 99mTc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with 99mTc 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

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Destruction of leishmania mexicana amazonensis amastigotes within macrophages in culture by phenazine methosulfate and other electron carriers  

OpenAIRE

Exposure of macrophages infected with Leishmania mexicana amazonensis to phenazine methosulfate (PMS) resulted in rapid damage and disappearance of the intracellular amastigotes without obvious ill effects to the host cells. The reduction of the percent infection was related to the concentration of PMS and to the duration of the pulse. Most Leishmania disappeared within 2 h of a 2-h pulse with 10 ?M of the drug. In contrast, pretreatment of the macrophages with PMS followed by removal of the...

Rabinovitch, M.; Dedet, J-p; Ryter, A.; Robineaux, R.; Topper, G.; Brunet, E.

1982-01-01

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Experimental infection with Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) amazonensis in the marmoset, Callithrix penicillata (Primates: Callithricidae)  

Scientific Electronic Library Online (English)

Full Text Available Foureen marmosets (Callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of Leishmania (Viannia) brazilensis (L. (V) b.) strains MHOM/BR/83/LTB-300MHOM/BR/85/LTB-12 MHOM/BR/81/LTB-179 and MHOM/BR/82/LTB-250. The evolution of subsequent lesions was studied for 15 [...] to 75 weeks post-inoculation (PI). All but of the L. (V) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by the appearance of subcutaneous nodules containing parasites. parasites were isolated by culture (Difco Blood Agar) from all 11 positive animals. The maximum size of the lesions was variable and ranged between 37 mm² to 107 mm². Ulceration of primary nodules became evident after 3 to 12 weeks in all infected marmosets, but was faster and larger in 5 of the 11 animals. The active lesions persisted in 9 out of 11 Callithrix until the en of the observation period, which varied from 15-75 weeks. In 3 animals spontaneous healing of their lesions (13 to 25 weeks, PI) was observed buth with cryptic parasitism. In another 2 infected animals there was regression followed by reactivation of the cutaneous lesions. The appearance of smaller satellite lesions adjacent to primary ones, as well as metastatic lesions to the ear lobes, were documented in 2 animals. Promastigotes of L. (Leishmania) amazonensis (L.(L)a.) MHOM/BR/77/LTB-16 were inoculated in 1 marmoset. This animal remained chronically infected for 6 months and the lesions developed in a similar manner to L.(V)b. infected marmosets. No significant differences in clinical and parasitological behaviour were observed between promastigote or amastigote derived infections of the 2 species. Both produced chronic, long lasting lesions which eventually healed. The same was true for parameters of size and ulceration. Skin tests converted to parasite in 11 of 15 inected masmosets and in 10 of 12 parasite positive animnals. Moderate levels of circulating antibodies were also observed by IFAT /IgG assays. In spite of the failure to reproduce the mucosal form of the disease, an important aspect of the Callithrix model in experimental cutaneous leishmaniasis lies in the reproduction of 2 clinical events that are common in humans, namely, the chronic ulceration and spontaneous healing of the lesions.

César A. Cuba, Cuba; Vera, Ferreira; Maria, Bampi; Albino, Magalhães; Philip D., Marsden; Alejandro, Vexenat; Milton Thiago de, Mello.

1990-12-01

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Resveratrol is active against Leishmania amazonensis: in vitro effect of its association with Amphotericin B.  

Science.gov (United States)

Resveratrol is a polyphenol found in black grapes and red wine and has many biological activities. In this study, we evaluated the effect of resveratrol alone and in association with amphotericin B (AMB) against Leishmania amazonensis. Our results demonstrate that resveratrol possesses both antipromastigote and antiamastigote effects, with 50% inhibitory concentrations (IC50s) of 27 and 42 ?M, respectively. The association of resveratrol with AMB showed synergy for L. amazonensis amastigotes, as demonstrated by the mean sums of fractional inhibitory index concentration (mean ?FIC) of 0.483, although for promastigotes, this association was indifferent. Treatment with resveratrol increased the percentage of promastigotes in the sub-G0/G1 phase of the cell cycle, reduced the mitochondrial potential, and showed an elevated choline peak and CH2-to-CH3 ratio in the nuclear magnetic resonance (NMR) spectroscopy analysis; all these features indicate parasite death. Resveratrol also decreased the activity of the enzyme arginase in uninfected and infected macrophages with and without stimulation with interleukin-4 (IL-4), also implicating arginase inhibition in parasite death. The anti-Leishmania effect of resveratrol and its potential synergistic association with AMB indicate that these compounds should be subjected to further studies of drug association therapy in vivo. PMID:25114129

Ferreira, Christian; Soares, Deivid Costa; Nascimento, Michelle Tanny Cunha do; Pinto-da-Silva, Lucia Helena; Sarzedas, Carolina Galvão; Tinoco, Luzineide Wanderley; Saraiva, Elvira Maria

2014-10-01

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Evaluation of macroalgae sulfated polysaccharides on the Leishmania (L.) amazonensis promastigote.  

Science.gov (United States)

The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 ?g/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 ?g/mL and 137.4 ?g/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 ?g/mL, 49.3 ?g/mL, 73.2 ?g/mL, and 99.8 ?g/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites. PMID:23519148

Lehnhardt Pires, Camila; Rodrigues, Selma Dzimidas; Bristot, Daniel; Gaeta, Henrique Hessel; de Oliveira Toyama, Daniela; Lobo Farias, Wladimir Ronald; Toyama, Marcos Hikari

2013-03-01

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Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L. amazonensis Promastigote  

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Full Text Available The sulfated polysaccharides from Solieria filiformis (Sf, Botryocladia occidentalis (Bo, Caulerpa racemosa (Cr and Gracilaria caudata (Gc were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L. amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 ?g/mL. The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 ?g/mL and 137.4 ?g/mL. In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 ?g/mL, 49.3 ?g/mL, 73.2 ?g/mL, and 99.8 ?g/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L. amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.

Marcos Hikari Toyama

2013-03-01

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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)

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 LLCMK2 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 60Co irradiation most venom loses signi/sup>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)

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The stepwise selection for ketoconazole resistance induces upregulation of C14-demethylase (CYP51 in Leishmania amazonensis  

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Full Text Available Ketoconazole is a clinically safe antifungal agent that also inhibits the growth of Leishmania spp. A study was undertaken to determine whether Leishmania parasites are prone to becoming resistant to ketoconazole by upregulating C14-demethylase after stepwise pharmacological pressure. Leishmania amazonensis promastigotes [inhibitory concentration (IC50 = 2 µM] were subjected to stepwise selection with ketoconazole and two resistant lines were obtained, La8 (IC50 = 8 µM and La10 (IC50 = 10 µM. As a result, we found that the resistance level was directly proportional to the C14-demethylase mRNA expression level; we also observed that expression levels were six and 12 times higher in La8 and La10, respectively. This is the first demonstration that L. amazonensis can up-regulate C14-demethylase in response to drug pressure and this report contributes to the understanding of the mechanisms of parasite resistance.

Valter Viana Andrade-Neto

2012-05-01

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Entry and survival of Leishmania amazonensis amastigotes within phagolysosome-like vacuoles that shelter Coxiella burnetii in Chinese hamster ovary cells.  

OpenAIRE

Coxiella burnetii, a rickettsia, and Leishmania amazonensis, a protozoan flagellate, lodge in their host cells within large phagolysosome-like vacuoles. In the present study, C. burnetii-infected Vero or CHO cells were superinfected with L. amazonensis amastigotes to determine if these parasites can home to and survive within heterologous vacuoles. Six hours after superinfection, Leishmania amastigotes were located almost exclusively within large Coxiella-containing vacuoles. Thereafter, the ...

Veras, P. S.; Moulia, C.; Dauguet, C.; Tunis, C. T.; Thibon, M.; Rabinovitch, M.

1995-01-01

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In vitro activity of the hydroethanolic extract and biflavonoids isolated from Selaginella sellowii on Leishmania (Leishmania) amazonensis  

Scientific Electronic Library Online (English)

Full Text Available This study is the first phytochemical investigation of Selaginella sellowii and demonstrates the antileishmanial activity of the hydroethanolic extract from this plant (SSHE), as well as of the biflavonoids amentoflavone and robustaflavone, isolated from this species. The effects of these substances [...] were evaluated on intracellular amastigotes of Leishmania (Leishmania) amazonensis, an aetiological agent of American cutaneous leishmaniasis. SSHE was highly active against intracellular amastigotes [the half maximum inhibitory concentration (IC50) = 20.2 µg/mL]. Fractionation of the extract led to the isolation of the two bioflavonoids with the highest activity: amentoflavone, which was about 200 times more active (IC50 = 0.1 ?g/mL) and less cytotoxic than SSHE (IC50 = 2.2 and 3 ?g/mL, respectively on NIH/3T3 and J774.A1 cells), with a high selectivity index (SI) (22 and 30), robustaflavone, which was also active against L. amazonensis (IC50 = 2.8 µg/mL), but more cytotoxic, with IC50 = 25.5 µg/mL (SI = 9.1) on NIH/3T3 cells and IC50 = 3.1 µg/mL (SI = 1.1) on J774.A1 cells. The production of nitric oxide (NO) was lower in cells treated with amentoflavone (suggesting that NO does not contribute to the leishmanicidal mechanism in this case), while NO release was higher after treatment with robustaflavone. S. sellowii may be a potential source of biflavonoids that could provide promising compounds for the treatment of cutaneous leishmaniasis.

Yasmin Silva, Rizk; Alice, Fischer; Marillin de Castro, Cunha; Patrik Oening, Rodrigues; Maria Carolina Silva, Marques; Maria de Fátima Cepa, Matos; Mônica Cristina Toffoli, Kadri; Carlos Alexandre, Carollo; Carla Cardozo Pinto de, Arruda.

1050-10-01

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In vitro activity of the hydroethanolic extract and biflavonoids isolated from Selaginella sellowii on Leishmania (Leishmania) amazonensis  

Science.gov (United States)

This study is the first phytochemical investigation of Selaginella sellowii and demonstrates the antileishmanial activity of the hydroethanolic extract from this plant (SSHE), as well as of the biflavonoids amentoflavone and robustaflavone, isolated from this species. The effects of these substances were evaluated on intracellular amastigotes of Leishmania (Leishmania) amazonensis, an aetiological agent of American cutaneous leishmaniasis. SSHE was highly active against intracellular amastigotes [the half maximum inhibitory concentration (IC50) = 20.2 µg/mL]. Fractionation of the extract led to the isolation of the two bioflavonoids with the highest activity: amentoflavone, which was about 200 times more active (IC50 = 0.1 ?g/mL) and less cytotoxic than SSHE (IC50 = 2.2 and 3 ?g/mL, respectively on NIH/3T3 and J774.A1 cells), with a high selectivity index (SI) (22 and 30), robustaflavone, which was also active against L. amazonensis (IC50 = 2.8 µg/mL), but more cytotoxic, with IC50 = 25.5 µg/mL (SI = 9.1) on NIH/3T3 cells and IC50 = 3.1 µg/mL (SI = 1.1) on J774.A1 cells. The production of nitric oxide (NO) was lower in cells treated with amentoflavone (suggesting that NO does not contribute to the leishmanicidal mechanism in this case), while NO release was higher after treatment with robustaflavone. S. sellowii may be a potential source of biflavonoids that could provide promising compounds for the treatment of cutaneous leishmaniasis. PMID:25591109

Rizk, Yasmin Silva; Fischer, Alice; Cunha, Marillin de Castro; Rodrigues, Patrik Oening; Marques, Maria Carolina Silva; Matos, Maria de Fátima Cepa; Kadri, Mônica Cristina Toffoli; Carollo, Carlos Alexandre; de Arruda, Carla Cardozo Pinto

2014-01-01

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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)

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)

Bonetti, Franco Claudio

2002-07-01

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

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Full Text Available Abstract Background Mammal macrophages (M? 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 M?. Results Using BALB/c mouse bone marrow-derived M? loaded or not with amastigotes, we analyzed the transcriptional signatures of M? 24 h later, when the amastigote population was growing. Total RNA from M? 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 M? lipid and polyamine pathways. Moreover, these M? hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

Lang Thierry

2009-03-01

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Cell populations in lesions of cutaneous leishmaniasis of leishmania (L.) amazonensis- infected rhesus macaques, Macaca mulatta  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The cellular nature of the infiltrate in cutaneous lesion of rhesus monkeys experimentally infected with Leishmania (L.) amazonensis was characterized by immunohistochemistry. Skin biopsies from infected animals with active or healing lesions were compared to non-infected controls (three of each typ [...] e) to quantitate inflammatory cell types. Inflammatory cells (composed of a mixture of T lymphocyte subpopulations, macrophages and a small number of natural killer cells and granulocytes) were more numerous in active lesions than in healing ones. T-cells accounted for 44.7 ± 13.1% of the infiltrate in active lesions (versus CD2+= 40.3 ± 5.7% in healing lesions) and T-cell ratios favor CD8+ cells in both lesion types. The percentage of cells expressing class II antigen (HLA-DR+) in active lesions (95 ± 7.1%) was significantly higher (P

VF, Amaral; C, Pirmez; AJS, Gonçalves; V, Ferreira; G, Grimaldi Jr.

2000-04-01

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Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi  

Directory of Open Access Journals (Sweden)

Full Text Available Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1, 11alpha,12alpha-oxidetaraxeryl acetate (2 and lupeol (3, as well as the flavonoids apigenin (6, kaempferol (7, crysoeriol (8 and luteolin (9 were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6, (7 and (9 showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1, acetate de 11alfa,12-oxidotaraxeril (2 e lupeol (3, assim como os flavonóides apigenina (6, caenferol (7, crisoeriol (8 e luteolina (9 mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6, (7 e (9 apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi.

Elisandra Cristina Schinor

2007-06-01

65

Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi / Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1), acetate de 11alfa,12-oxidotaraxeril (2) e lupeol (3), assim como os flavonóides apigenina (6), caenferol (7), crisoeriol (8) e luteolina (9 [...] ) mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6), (7) e (9) apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi. Abstract in english Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteo [...] lin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.

Elisandra Cristina, Schinor; Marcos José, Salvador; Elisabeth Mieko Furusho, Pral; Silvia Celina, Alfieri; Sérgio, Albuquerque; Diones Aparecida, Dias.

2007-06-01

66

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  

OpenAIRE

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...

Patrícia Shima Luize; Tatiana Shioji Tiuman; Luis Gustavo Morello; Paloma Korehiza Maza; Tânia Ueda-Nakamura; Benedito Prado Dias Filho; Diógenes Aparício Garcia Cortez; João Carlos Palazzo de Mello; Celso Vataru Nakamura

2005-01-01

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Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi  

OpenAIRE

Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.O fra...

Elisandra Cristina Schinor; Marcos José Salvador; Elisabeth Mieko Furusho Pral; Silvia Celina Alfieri; Sérgio De Albuquerque; Diones Aparecida Dias

2007-01-01

68

Extracellular matrix alterations in experimental Leishmania amazonensis infection in susceptible and resistant mice  

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Full Text Available Abstract Leishmania is inoculated, by the bite of an infected sandfly, into the skin of the host, where the promastigotes are phagocyted by dermal macrophages. The dermal region comprises cells and abundant extracellular matrix. Studies show that matrix metalloproteinases play an important role in host defense responses against pathogens in mammals and that their activities lead to the production of antimicrobial peptides. The aim of this study is to evaluate the changes in the distribution of fibronectin and laminin as well as in the elastic system fibres during the course of infection caused by Leishmania amazonensis in mice with distinct genetic backgrounds of susceptibility to this parasite. The results showed that BALB/c presented an enhancement of fibronectin during the course of infection when compared to their control group while the infected or non-infected C3H.He showed a decrease of this protein at end of the experiment. Laminin, on the other hand, remained unaltered in both strains. Also in both BALB/c and C3H.He mice the elastic and elaunin fibres remained unchanged while the oxytalan fibres decreased along the experiment. Ninety days after the infection C3H.He mice had recovered their capacity to produce oxytalan fibres.

Silva-Almeida Mariana

2012-02-01

69

A microplate assay for Leishmania amazonensis promastigotes expressing multimeric green fluorescent protein.  

Science.gov (United States)

Convenient and economical assays capable of screening many compounds are vital to advance the development of drug therapy. This is particularly important for many of the infections that occur mainly in the Third World. The development of such a spectrofluorometric assay for the protozoan parasite Leishmania is presented here. Using multimeric (four monomers) green fluorescent protein (GFP), Leishmania amazonensis promastigotes were generated with brightness measurable in 96-well microtiter plates. The promastigotes maintained the parental characteristics, were infective to murine macrophages and to mice, and the level of GFP fluorescence corresponded to the number of inoculated cells. The feasibility of using this assay for testing drugs kinetically and in a concentration-dependent manner, under microplate culture condition, was demonstrated with amphotericin B and the herbicide oryzalin, respectively. This assay is the first to allow a real-time analysis of antileishmanial agents with live promastigotes. The method of expressing multimeric GFP for in vitro drug screening is likely to be extendable to many species of parasitic protozoa. PMID:12632163

Chan, Marion Man-Ying; Bulinski, J Chloe; Chang, Kwang-Poo; Fong, Dunne

2003-03-01

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Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania amazonensis. A comparative study between mefloquine and aminosidine  

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Full Text Available One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 106 Leishmania (Leishmania amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1 oral mefloquine hydrochloride treatment (16mg/kg/day/10 days, 2 intramuscular aminosidine (Paromomycin® treatment (20mg/kg/20 days and 3 control. Twenty six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation, and one six weeks later (fifteen weeks after inoculation. Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine and Group 3 (control subjects. Group 2 animals (aminosidine presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment. b both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.

Galvão Letícia Oba

2000-01-01

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Inmunización con subgenoteca de Leishmania amazonensis protege contra el reto a ratones BALB/c  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se construyó una genoteca de Leishmania amazonensis en vector de expresión en células eucariotas (pEF1HisA, pEF1HisB, pEF1HisC). Se prepararon 2 subgenotecas con un número aproximado de 500 clones cada una y ratones BALB/c fueron inmunizados con 50 mg/0,1 mL de ADN de cada una; 2 inmunizaciones por [...] vía IM, con 15 d de intervalo fueron realizadas. Grupos de ratones controles fueron inmunizados con ADN del plásmido vacío, con antígeno soluble del parásito (100 mg/0,1 mL) y solución salina fisiológica. Se midió el tamaño de las lesiones durante 12 semanas y al final del experimento, la carga parasitaria en los sitios de lesión fue determinada por el método de microtitulación en placas. Los ratones inmunizados con ADN 1, controlaron el tamaño de las lesiones, así como también los inmunizados con antígenos solubles, lo que alcanzó diferencia estadística (p Abstract in english A genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC) was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were a [...] dministered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL) and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNA1 and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p

Ana M, Montalvo Álvarez; Lianet, Monzote Fidalgo; Lisset, Fonseca Géigel; Ivón, Montano Goodridge; Luis, Fonte Galindo; Manuel, Soto.

2004-08-01

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Inmunización con subgenoteca de Leishmania amazonensis protege contra el reto a ratones BALB/c  

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Full Text Available Se construyó una genoteca de Leishmania amazonensis en vector de expresión en células eucariotas (pEF1HisA, pEF1HisB, pEF1HisC. Se prepararon 2 subgenotecas con un número aproximado de 500 clones cada una y ratones BALB/c fueron inmunizados con 50 mg/0,1 mL de ADN de cada una; 2 inmunizaciones por vía IM, con 15 d de intervalo fueron realizadas. Grupos de ratones controles fueron inmunizados con ADN del plásmido vacío, con antígeno soluble del parásito (100 mg/0,1 mL y solución salina fisiológica. Se midió el tamaño de las lesiones durante 12 semanas y al final del experimento, la carga parasitaria en los sitios de lesión fue determinada por el método de microtitulación en placas. Los ratones inmunizados con ADN 1, controlaron el tamaño de las lesiones, así como también los inmunizados con antígenos solubles, lo que alcanzó diferencia estadística (pA genomic library of Leishmania amazonensis in expression vector of eukaryote cells (pEF1HisA, pEF1HisB, pEF1HisC was prepared. Also two subgenomic libraries having each 500 clones approximately were created and BALB/c mice were immunized with 50 mg/0,1 mL of DNA from each. Two immunizations were administered intramuscularly at 15-day interval. Groups of control mice were immunized with DNA from empty plasmid pEF1His, with soluble parasite antigen (100 mg/0,1 mL and saline solution. The size of lesions was measured for 12 weeks and at the end of the experiment, the parasite load at lesion sites was determined by plaque microtitration method. In mice immunized with subgenomic library DNA1 and with soluble antigens,the size of lesions was controlled, which reached an statistical difference (p< 0,05 in relation to the rest of groups whose lesions increased. The parasite load found in lesion sites confirmed the previous results; the number of promastigots was significantly lower in those mice already protected. It was concluded that in subgenomic library DNA1 there should be genes or gene fragments whose in vivo expression induces protective immune response against the challenge in the murine model used

Ana M Montalvo Álvarez

2004-08-01

73

The stepwise selection for ketoconazole resistance induces upregulation of C14-demethylase (CYP51) in Leishmania amazonensis  

Scientific Electronic Library Online (English)

Full Text Available Ketoconazole is a clinically safe antifungal agent that also inhibits the growth of Leishmania spp. A study was undertaken to determine whether Leishmania parasites are prone to becoming resistant to ketoconazole by upregulating C14-demethylase after stepwise pharmacological pressure. Leishmania ama [...] zonensis promastigotes [inhibitory concentration (IC)50 = 2 µM] were subjected to stepwise selection with ketoconazole and two resistant lines were obtained, La8 (IC50 = 8 µM) and La10 (IC50 = 10 µM). As a result, we found that the resistance level was directly proportional to the C14-demethylase mRNA expression level; we also observed that expression levels were six and 12 times higher in La8 and La10, respectively. This is the first demonstration that L. amazonensis can up-regulate C14-demethylase in response to drug pressure and this report contributes to the understanding of the mechanisms of parasite resistance.

Valter Viana, Andrade-Neto; Herbert Leonel de, Matos-Guedes; Daniel Cláudio de Oliveira, Gomes; Marilene Marcuzzo do, Canto-Cavalheiro; Bartira, Rossi-Bergmann; Eduardo Caio, Torres-Santos.

2012-05-01

74

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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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.

Patrícia Shima Luize

2005-03-01

75

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  

Scientific Electronic Library Online (English)

Full Text Available 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. Abstract in english 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 Trypano [...] soma 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.

Patrícia Shima, Luize; Tatiana Shioji, Tiuman; Luis Gustavo, Morello; Paloma Korehiza, Maza; Tânia, Ueda-Nakamura; Benedito Prado, Dias Filho; Diógenes Aparício Garcia, Cortez; João Carlos Palazzo de, Mello; Celso Vataru, Nakamura.

2005-03-01

76

Determination of femto Newton forces and fluid viscosity using optical tweezers: application to Leishmania amazonensis  

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The objective of this research is to use the displacements of a polystyrene microsphere trapped by an optical tweezers (OT) as a force transducer in mechanical measurements in life sciences. To do this we compared the theoretical optical and hydrodynamic models with experimental data under a broad variation of parameters such as fluid viscosity, refractive index, drag velocity and wall proximities. The laser power was measured after the objective with an integration sphere because normal power meters do not provide an accurate measurement for beam with high numerical apertures. With this careful laser power determination the plot of the optical force (calculated by the particle displacement) versus hydrodynamic force (calculated by the drag velocity) under very different conditions shows an almost 45 degrees straight line. This means that hydrodynamic models can be used to calibrate optical forces and vice-versa. With this calibration we observed the forces of polystyrene bead attached to the protozoa Leishmania amazonensis, responsible for a serious tropical disease. The force range is from 200 femto Newtons to 4 pico Newtons and these experiments shows that OT can be used for infection mechanism and chemotaxis studies in parasites. The other application was to use the optical force to measure viscosities of few microliters sample. Our result shows 5% accuracy measurements.

Fontes, Adriana; Giorgio, Selma; de Castro, Archimedes B., Jr.; Neto, Vivaldo M.; Pozzo, Liliana d. Y.; Marques, Gustavo P.; Barbosa, Luiz C.; Cesar, Carlos L.

2005-03-01

77

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 t [...] he 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.

Angela Rapela, Medeiros; Wilson A, Silva Jr; Ana Maria, Roselino.

78

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

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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.

Angela Rapela Medeiros

2008-01-01

79

Determination of fluid viscosity and femto Newton forces of Leishmania amazonensis using optical tweezers  

Science.gov (United States)

The displacements of a polystyrene microsphere trapped by an optical tweezers (OT) can be used as a force transducer for mechanical measurements in life sciences such as the measurement of forces of living microorganisms or the viscosity of local fluids. The technique we used allowed us to measure forces on the 200 femto Newtons to 4 pico Newtons range of the protozoa Leishmania amazonensis, responsible for a serious tropical disease. These observations can be used to understand the infection mechanism and chemotaxis of these parasites. The same technique was used to measure viscosities of few microliters sample with agreement with known samples better than 5%. To calibrate the force as a function of the microsphere displacement we first dragged the microsphere in a fluid at known velocity for a broad range of different optical and hydrodynamical parameters. The hydrodynamical model took into account the presence of two walls and the force depends on drag velocity, fluid viscosity and walls proximities, while the optical model in the geometric optics regime depends on the particle and fluid refractive indexes and laser power. To measure the high numerical (NA) aperture laser beam power after the objective we used an integration sphere to avoid the systematic errors of usual power meters for high NA beams. After this careful laser power measurement we obtained an almost 45 degrees straight line for the plot of the optical force (calculated by the particle horizontal displacement) versus hydrodynamic force (calculated by the drag velocity) under variation of all the parameters described below. This means that hydrodynamic models can be used to calibrate optical forces, as we have done for the parasite force measurement, or vice-versa, as we did for the viscosity measurements.

Fontes, Adriana; Giorgio, Selma; de Castro, Archimedes, Jr.; Neto, Vivaldo M.; de Y. Pozzo, Liliana; de Thomaz, Andre A.; Barbosa, Luiz C.; Cesar, Carlos L.

2005-08-01

80

Episomal Expression of Specific Sense and Antisense mRNAs in Leishmania amazonensis: Modulation of gp63 Level in Promastigotes and Their Infection of Macrophages In Vitro  

OpenAIRE

The major surface glycoprotein (gp63) of Leishmania amazonensis is a metalloprotease implicated in the infection of mammalian macrophages. The expression of gp63 and its participation in this infection were further examined by modulating the level of this molecule in a virulent gp63-abundant wild-type clone. Promastigotes were transfected with gp63 genes cloned into a Leishmania-specific vector in two different orientations, leading to the expression of gp63 sense and antisense RNAs. With inc...

Chen, De-qiao; Kolli, Bala Krishna; Yadava, Nagendra; Lu, Hong Gang; Gilman-sachs, Alice; Peterson, Daniel A.; Chang, Kwang-poo

2000-01-01

81

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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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.

Debora B. Petropolis

2014-04-01

82

Epoxy-?-Lapachone Has In Vitro and In Vivo Anti-Leishmania (Leishmania) amazonensis Effects and Inhibits Serine Proteinase Activity in This Parasite.  

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Leishmania (Leishmania) amazonensis is a protozoan that causes infections with a broad spectrum of clinical manifestations. The currently available chemotherapeutic treatments present many problems, such as several adverse side effects and the development of resistant strains. Natural compounds have been investigated as potential antileishmanial agents, and the effects of epoxy-?-lapachone on L. (L.) amazonensis were analyzed in the present study. This compound was able to cause measurable effects on promastigote and amastigote forms of the parasite, affecting plasma membrane organization and leading to death after 3 h of exposure. This compound also had an effect in experimentally infected BALB/c mice, causing reductions in paw lesions 6 weeks after treatment with 0.44 mM epoxy-?-lapachone (mean lesion area, 24.9 ± 2.0 mm(2)), compared to untreated animals (mean lesion area, 30.8 ± 2.6 mm(2)) or animals treated with Glucantime (mean lesion area, 28.3 ± 1.5 mm(2)). In addition, the effects of this compound on the serine proteinase activities of the parasite were evaluated. Serine proteinase-enriched fractions were extracted from both promastigotes and amastigotes and were shown to act on specific serine proteinase substrates and to be sensitive to classic serine proteinase inhibitors (phenylmethylsulfonyl fluoride, aprotinin, and antipain). These fractions were also affected by epoxy-?-lapachone. Furthermore, in silico simulations indicated that epoxy-?-lapachone can bind to oligopeptidase B (OPB) of L. (L.) amazonensis, a serine proteinase, in a manner similar to that of antipain, interacting with an S1 binding site. This evidence suggests that OPB may be a potential target for epoxy-?-lapachone and, as such, may be related to the compound's effects on the parasite. PMID:25583728

Souza-Silva, Franklin; Bourguignon, Saulo Cabral; Pereira, Bernardo Acácio Santini; Côrtes, Luzia Monteiro de Castro; de Oliveira, Luiz Filipe Gonçalves; Henriques-Pons, Andrea; Finkelstein, Lea Cysne; Ferreira, Vitor Francisco; Carneiro, Paula Fernandes; de Pinho, Rosa Teixeira; Caffarena, Ernesto Raul; Alves, Carlos Roberto

2015-04-01

83

Therapeutic efficacy induced by the oral administration of Agaricus blazei Murill against Leishmania amazonensis.  

Science.gov (United States)

The development of therapeutic alternatives to treat leishmaniasis has received considerable attention. The present study aimed to investigate the efficacy of the Agaricus blazei Murill water extract (AbM) to treat BALB/c mice infected with Leishmania amazonensis. First, a dose-titration curve was performed. The most well-defined concentration able to induce the most effective results in the infected animals, considering a daily administration of the product, was that of 100 mg kg(-1) day(-1). In this context, the AbM was administered orally, beginning on day 0 up to 20 days postinfection. Additional animals were treated with amphotericin B (AmpB, 5 mg kg(-1) day(-1)) by peritoneal route for the same period of time, while the control group received distilled water. The animals were evaluated at 14 weeks post-infection, at which time the parasitological and immunological parameters were analyzed. Mice treated with the AbM presented a 60% reduction in the inflammation of infected footpads as compared to untreated control-infected mice. Moreover, in the treated mice, as compared to the untreated controls, approximately 60 and 66% reductions could be observed in the parasite burdens of the footpad and draining lymph nodes, respectively. In addition, no parasites could be detected in the spleen of treated mice at week 14 postinfection. These treated animals produced significantly higher levels of interferon gamma (IFN-?) and nitric oxide (NO), higher levels of parasite-specific IgG2a isotype antibodies, and lower levels of interleukin (IL)-4, and IL-10 in the spleen and lymph node cell cultures than did the controls. Differences could be observed by comparing animals treated with AbM to those treated with AmpB, as indicated by a significant reduction in tissue parasitism, higher levels of IFN-? and NO, and lower levels of IL-4 and IL-10, as well as by a decreased hepatic toxicity. In conclusion, the present study's data show that the A. blazei Murill water extract presents a high potential for the treatment of leishmaniasis, although additional studies on mice, as well as on other mammal hosts, are warranted in an attempt to determine this extract's true efficacy as compared to other known therapeutic products. PMID:22797606

Valadares, Diogo G; Duarte, Mariana C; Ramírez, Laura; Chávez-Fumagalli, Miguel A; Lage, Paula S; Martins, Vivian T; Costa, Lourena E; Ribeiro, Tatiana G; Régis, Wiliam C B; Soto, Manuel; Fernandes, Ana Paula; Tavares, Carlos A P; Coelho, Eduardo A F

2012-10-01

84

Salivary gland homogenates from wild-caught sand flies Lutzomyia flaviscutellata and Lutzomyia (Psychodopygus) complexus showed inhibitory effects on Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis infection in BALB/c mice.  

Science.gov (United States)

During the natural transmission of Leishmania parasites, the infected sand fly female regurgitates promastigotes into the host's skin together with its saliva. It has been reported that vector saliva contains immunomodulatory molecules that facilitate the establishment of infection. Thus, the main objective of this study was to evaluate the specificity of Lutzomyia (Lu.) flaviscutellata and Lu. (Psychodopygus) complexus salivas on the infectivity of Leishmania (L.) (Leishmania) amazonensis and L. (Viannia) braziliensis, respectively. BALB/c mice were inoculated into the skin of hind footpad with L. (L.) amazonensis and L. (V.) braziliensis promastigotes in the absence or presence of Lu. flaviscutellata and Lu. (P.) complexus salivary gland homogenates (SGHs). The evolution of the infection was evaluated by lesion size, histopathological analysis and determination of the parasite load in the skin biopsies collected from the site of infection at 4 and 8 weeks PI. The lesion size and the parasite load of both groups of mice infected in the presence of SGHs were smaller than the control groups. The histopathological features showed that the inflammatory reaction was less prominent in the groups of mice infected in the presence of both SGHs when compared to the control group. The results showed that the presence of SGHs of Lu. flaviscutellata and Lu. (P.) complexus led to induction of processes that were disadvantageous to parasite establishment during infection by L. (L.) amazonensis and L. (V.) braziliensis. An inhibitory effect on Leishmania infection could be observed in both groups inoculated with SGHs, especially when the SGH from Lu. (P.) complexus was used. PMID:25476864

Francesquini, Fernanda C; Silveira, Fernando T; Passero, Luiz Felipe D; Tomokane, Thaise Y; Carvalho, Ana Kely; Corbett, Carlos Eduardo P; Laurenti, Márcia D

2014-12-01

85

Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and B [...] a276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-?, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-? in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression.

Valderes L de, Souza; Patrícia ST, Veras; Marcus, Welby-Borges; Tânia MC, Silva; Bruna R, Leite; Rodrigo B, Ferraro; José R, Meyer-Fernandes; Aldina, Barral; Jackson Mauricio Lopes, Costa; Luiz AR de, Freitas.

2011-02-01

86

Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice  

Directory of Open Access Journals (Sweden)

Full Text Available Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125, diffuse cutaneous (Ba276 or visceral leishmaniasis (Ba109. Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-?, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-? in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression.

Valderes L de Souza

2011-02-01

87

Molecular Modeling Approaches for Determining Gene Function: application to a Putative Poly-A Binding Protein from Leishmania amazonensis (LaPABP)  

OpenAIRE

The great expansion in the number of genome sequencing projects has revealed the importance of computational methods to speed up the characterization of unknown genes. These studies have been improved by the use of three dimensional information from the predicted proteins generated by molecular modeling techniques. In this work, we disclose the structure-function relationship of a gene product from Leishmania amazonensis by applying molecular modeling and bioinformatics techniques. The analyz...

Fp, Silva-jr; Fz, Veyl; Clos, J.; Giovanni Simone, S.

2002-01-01

88

Cell-to-cell transfer of Leishmania amazonensis amastigotes is mediated by immunomodulatory LAMP-rich parasitophorous extrusions  

Science.gov (United States)

The last step of Leishmania intracellular life cycle is the egress of amastigotes from the host cell and their uptake by adjacent cells. Using multidimensional live imaging of long-term-infected macrophage cultures we observed that Leishmania amazonensis amastigotes were transferred from cell to cell when the donor host macrophage delivers warning signs of imminent apoptosis. They were extruded from the macrophage within zeiotic structures (membrane blebs, an apoptotic feature) rich in phagolysosomal membrane components. The extrusions containing amastigotes were selectively internalized by vicinal macrophages and the rescued amastigotes remain viable in recipient macrophages. Host cell apoptosis induced by micro-irradiation of infected macrophage nuclei promoted amastigotes extrusion, which were rescued by non-irradiated vicinal macrophages. Using amastigotes isolated from LAMP1/LAMP2 knockout fibroblasts, we observed that the presence of these lysosomal components on amastigotes increases interleukin 10 production. Enclosed within host cell membranes, amastigotes can be transferred from cell to cell without full exposure to the extracellular milieu, what represents an important strategy developed by the parasite to evade host immune system. PMID:24824158

Real, Fernando; Florentino, Pilar Tavares Veras; Reis, Luiza Campos; Ramos-Sanchez, Eduardo M; Veras, Patricia Sampaio Tavares; Goto, Hiro; Mortara, Renato Arruda

2014-01-01

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Ocular experimental leishmaniasis in C57BL/10 and BALB/c mice induced by Leishmania amazonensis infection.  

Science.gov (United States)

There are few studies on human ocular leishmaniasis found in the literature. The purpose of this study was to describe experimental ocular leishmaniasis, caused by Leishmania amazonensis evaluating two different infection routes: intravitreal and instillation in C57BL/10 and BALB/c mice. In this work all animals presented low anti-Leishmania IgM and IgG titers regardless of the infection route or mouse strain. The histopathological eye analysis showed that the mice inoculated by the intravitreal route developed more severe lesions, presenting parasites in the anterior region of the eye 60 days after infection. The C57BL/10 mice presented cells containing parasitophorous vacuoles associated with pigmented cells and inflammatory infiltrate, which included mast cells. Ninety days after infection no parasites could be found in either mouse strain, which led us to hypothesize that parasites had been eliminated. In this context, we show that both intravitreal and instillation routes were effective in promoting ocular leishmaniasis infections in C57BL/10 and BALB/c mice. There were no differences in the parasite infection between the two mouse models and it mimicked the ocular lesions described in symptomatic dogs in endemic areas of visceral leishmaniasis. PMID:23201219

Calabrese, K S; Silva, L S; Hardoim, D J; Souza, C S F; Abreu-Silva, A L

2013-02-01

90

Cell-to-cell transfer of Leishmania amazonensis amastigotes is mediated by immunomodulatory LAMP-rich parasitophorous extrusions.  

Science.gov (United States)

The last step of Leishmania intracellular life cycle is the egress of amastigotes from the host cell and their uptake by adjacent cells. Using multidimensional live imaging of long-term-infected macrophage cultures we observed that Leishmania amazonensis amastigotes were transferred from cell to cell when the donor host macrophage delivers warning signs of imminent apoptosis. They were extruded from the macrophage within zeiotic structures (membrane blebs, an apoptotic feature) rich in phagolysosomal membrane components. The extrusions containing amastigotes were selectively internalized by vicinal macrophages and the rescued amastigotes remain viable in recipient macrophages. Host cell apoptosis induced by micro-irradiation of infected macrophage nuclei promoted amastigotes extrusion, which were rescued by non-irradiated vicinal macrophages. Using amastigotes isolated from LAMP1/LAMP2 knockout fibroblasts, we observed that the presence of these lysosomal components on amastigotes increases interleukin 10 production. Enclosed within host cell membranes, amastigotes can be transferred from cell to cell without full exposure to the extracellular milieu, what represents an important strategy developed by the parasite to evade host immune system. PMID:24824158

Real, Fernando; Florentino, Pilar Tavares Veras; Reis, Luiza Campos; Ramos-Sanchez, Eduardo M; Veras, Patricia Sampaio Tavares; Goto, Hiro; Mortara, Renato Arruda

2014-10-01

91

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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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 incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas.

R. A. Freitas

1989-09-01

92

Molecular Modeling Approaches for Determining Gene Function: application to a Putative Poly-A Binding Protein from Leishmania amazonensis (LaPABP  

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Full Text Available The great expansion in the number of genome sequencing projects has revealed the importance of computational methods to speed up the characterization of unknown genes. These studies have been improved by the use of three dimensional information from the predicted proteins generated by molecular modeling techniques. In this work, we disclose the structure-function relationship of a gene product from Leishmania amazonensis by applying molecular modeling and bioinformatics techniques. The analyzed sequence encodes a 159 aminoacids polypeptide (estimated 18 kDa and was denoted LaPABP for its high homology with poly-A binding proteins from trypanosomatids. The domain structure, clustering analysis and a three dimensional model of LaPABP, basically obtained by homology modeling on the structure of the human poly-A binding protein, are described. Based on the analysis of the electrostatic potential mapped on the model's surface and conservation of intramolecular contacts responsible for folding stabilization we hypothesize that this protein may have less avidity to RNA than it's L. major counterpart but still account for a significant functional activity in the parasite. The model obtained will help in the design of mutagenesis experiments aimed to elucidate the mechanism of gene expression in trypanosomatids and serve as a starting point for its exploration as a potential source of targets for a rational chemotherapy.

FP Silva-Jr

2002-04-01

93

Molecular Modeling Approaches for Determining Gene Function: application to a Putative Poly-A Binding Protein from Leishmania amazonensis (LaPABP)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The great expansion in the number of genome sequencing projects has revealed the importance of computational methods to speed up the characterization of unknown genes. These studies have been improved by the use of three dimensional information from the predicted proteins generated by molecular mode [...] ling techniques. In this work, we disclose the structure-function relationship of a gene product from Leishmania amazonensis by applying molecular modeling and bioinformatics techniques. The analyzed sequence encodes a 159 aminoacids polypeptide (estimated 18 kDa) and was denoted LaPABP for its high homology with poly-A binding proteins from trypanosomatids. The domain structure, clustering analysis and a three dimensional model of LaPABP, basically obtained by homology modeling on the structure of the human poly-A binding protein, are described. Based on the analysis of the electrostatic potential mapped on the model's surface and conservation of intramolecular contacts responsible for folding stabilization we hypothesize that this protein may have less avidity to RNA than it's L. major counterpart but still account for a significant functional activity in the parasite. The model obtained will help in the design of mutagenesis experiments aimed to elucidate the mechanism of gene expression in trypanosomatids and serve as a starting point for its exploration as a potential source of targets for a rational chemotherapy.

FP, Silva-Jr; FZ, Veyl; J, Clos; S Giovanni, De Simone.

2002-04-01

94

Identification and characterization of new Leishmania promastigote surface antigens, LaPSA-38S and LiPSA-50S, as major immunodominant excreted/secreted components of L. amazonensis and L. infantum.  

Science.gov (United States)

We have previously demonstrated that sera from dogs vaccinated with excreted/secreted antigens (ESA) of Leishmania infantum promastigotes (LiESAp) mainly recognized an immunodominant antigen of 54 kDa. An anti-LiESAp-specific IgG2 humoral response was observed and associated to Th1-type response in vaccinated dogs. This response was highly correlated with a long-lasting and strong LiESAp-vaccine protection toward L. infantum experimental infection. In addition, it was also shown that dogs from the vaccinated group developed a selective IgG2 response against an immunodominant antigen of 45 kDa of Leishmania amazonensis ESA promastigotes (LaESAp). In order to identify and characterize these immunodominant antigens, a mouse monoclonal antibody (mAb F5) was produced by immunization against LaESAp. It was found to recognize the major antigenic targets of both LaESAp and LiESAp. Analysis with mAb F5 of L. amazonensis amastigote and promastigote cDNA expression libraries enabled the identification of clones encoding proteins with significant structural homology to the promastigote surface antigens named PSA-2/gp-46. Among them, one clone presented a full-length cDNA and encoded a novel L. amazonensis protein of 38.6 kDa calculated molecular mass (LaPSA-38S) sharing an amino acid sequence consistent with that of the PSA polymorphic family and a N-terminal signal peptide, characteristic of a secreted protein. We then screened a L. infantum promastigote DNA cosmid library using a cDNA probe derived from the LaPSA-38S gene and identified a full-length clone of a novel excreted/secreted protein of L. infantum with a calculated molecular mass of 49.2 kDa and named LiPSA-50S. The fact that a significant immunological reactivity was observed against PSA, suggests that these newly identified proteins could have an important immunoregulatory influence on the immune response. This hypothesis is supported by the fact that (i) these proteins were naturally excreted/secreted by viable Leishmania promastigotes and amastigotes, and (ii) they are selectively recognized by vaccinated and protected dogs. PMID:24614507

Bras-Gonçalves, Rachel; Petitdidier, Elodie; Pagniez, Julie; Veyrier, Renaud; Cibrelus, Prisca; Cavaleyra, Mireille; Maquaire, Sarah; Moreaux, Jérôme; Lemesre, Jean-Loup

2014-06-01

95

Enhancement of Leishmania amazonensis infection in BCG non-responder mice by BCG-antigen specific vaccine  

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Full Text Available Different patterns of cutaneous leishmaniasis can be induced when a challenge of alike dose of Leishmania amazonensis amastigotes in various inbred strains was applied. Two strains of mice, the Balb/c and C57 BL/10J, showed exceptional suscepbility, and 10(elevado a sexta potência amastigotes infective dose lead, to ulcerative progressive lesions with cutaneous metastasis and loss by necrosis of leg on wich the footpad primary lesion occured. Lesions were also progressive but in a lower degree when C3H/HeN and C57BL/6 were infected. Lesions progress slowly in DBA/2 mice presenting lesions wich reach a discreet peack after 12 weeks, do not heal but do not uncerate. DBA/2 mice is, therefore, a good model for immunomodualtion. In attempt to determine the influence of BCG in vaccination schedule using microsomal fraction, DBA/2 became an excellent model, since it is also a non-responder to BCG. Vaccination of DBA/2 mice, receiving the same 10(elevado a sexta potência BCG viable dose and 10 *g or 50 *g of protein content of microsomal fraction, lead to a progressive disease with time course similar to those observed in susceptible non-vaccinated C57BL/10J mice after 6 months of observation. An enhancement of infection in BCG non-responder mice suggests that use of BCG as immunostimulant in humans could be critical for both vaccination and immunoprophylactic strategies.

Kátia da Silva Calabrese

1992-01-01

96

In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13  

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Full Text Available SciELO Brazil | Language: English Abstract in english The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-? production. We have expanded such observations evaluating the profile and kinetics of [...] cytokines (IFN-?, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated of HV's PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-? responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-? production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-? responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-? is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection

Zirlane Castelo B, Coêlho; Maria Jania, Teixeira; Erika Freitas, Mota; Mércia Sindeaux, Frutuoso; João Santana da, Silva; Aldina, Barral; Manoel, Barral-Netto; Margarida Maria L, Pompeu.

2010-10-01

97

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

Science.gov (United States)

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 9?m 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.

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

2007-02-01

98

Sobre a sensibilidade da cultura de leucócitos circulantes na detecção de Leishmania no sangue periférico de pacientes com leishmaniose tegumentar  

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Full Text Available Foi investigada a presença de Leishmania, através da cultura de leucócitos circulantes, no sangue periférico de 60 pacientes portadores de leishmaniose tegumentar americana, nas suas diferentes formas clínicas, assim como nas principais fases evolutivas da doença. Biópsias de lesões cutâneas e/ou de mucosa desses pacientes foram obtidas com a finalidade de isolar e caracterizar os parasitas, através da técnica de anticorpos monoclonais. Dos 60 pacientes examinados, foram isoladas 40 amostras de Leishmania das lesões biopsiadas, sendo 5 de Leishmania (V. brasiliensis, 3 de L. (V. guyanensis, 1 de L. (V. lainsoni, 13 de L. (L. amazonensis e 18 não puderam ser caracterizados a nível específico, porém, reagiram com anticorpos monoclonais do grupo braziliensis. Quanto àpesquisa através das culturas de leucócitos circulantes, esta revelou resultados completamente negativos. Com base nesses achados, os autores concluíram ser pouco consistente atribuir valor à cultura de leucócitos para o diagnóstico da leishmaniose tegumentar.The possible presence of Leishmania in the peripheral blood of 60 patients with American cutaneous leishmaniasis was investigated by the culture of circulating leucocytes. Patients were selected with a variety ofclinical forms ofthe disease and in different evolutionary stages of infection. Biopsies of skin and/or mucosal lesions were made in order to isolate the parasites, which were identified using monoclonal antibodies. 40 isolations were obtained, including 5 of Leishmania (Viannia braziliensis, 3 L. (V. guyanensis, 1 L. (V. lainsoni, 13 L. (Leishmania amazonensis and 18 which could only be identified as parasites of the braziliensis complex. Cultures of circulanting leucocytes were consistently negative, and the authors conclude that this method is of little use in diagnosis of cutaneous or mucocutaneous leishmaniasis.

Fernando T. Silveira

1989-09-01

99

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

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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 60Co 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)

100

Chemotaxis study using optical tweezers to observe the strength and directionality of forces of Leishmania amazonensis  

Science.gov (United States)

The displacements of a dielectric microspheres trapped by an optical tweezers (OT) can be used as a force transducer for mechanical measurements in life sciences. This system can measure forces on the 50 femto Newtons to 200 pico Newtons range, of the same order of magnitude of a typical forces induced by flagellar motion. The process in which living microorganisms search for food and run away from poison chemicals is known is chemotaxy. Optical tweezers can be used to obtain a better understanding of chemotaxy by observing the force response of the microorganism when placed in a gradient of attractors and or repelling chemicals. This report shows such observations for the protozoa Leishmania amazomenzis, responsible for the leishmaniasis, a serious tropical disease. We used a quadrant detector to monitor the movement of the protozoa for different chemicals gradient. This way we have been able to observe both the force strength and its directionality. The characterization of the chemotaxis of these parasites can help to understand the infection mechanics and improve the diagnosis and the treatments employed for this disease.

Pozzo, Liliana d. Y.; Fontes, Adriana; de Thomaz, André A.; Barbosa, Luiz C.; Ayres, Diana C.; Giorgio, Selma; Cesar, Carlos L.

2006-08-01

101

Identification and purification of immunogenic proteins from nonliving promastigote polyvalent Leishmania vaccine (Leishvacin®) / Identificação e purificação de proteínas imunogênicas da vacina polivalente de promastigotas mortas de Leishmania (Leishvacin®)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Proteínas imunogênicas da vacina polivalente de promastigotas mortas de leishmanias (Leishvacin®) produzida pela Biobrás Bioquímica do Brasil, Montes Claros, Minas Gerais, Brasil foram identificadas e purificadas por eletroforese em gel de poliacrilamida e eletroeluição. Camundongos C57BL/10 foram v [...] acinados com proteínas de pesos moleculares estimados em 42, 46, 63, 66, 73, 87, 97 e 160kDa em três doses de 30µg de cada proteína combinada com 250µg de Corynebacteriumparvum em intervalos de 15 dias e desafiados com uma infecção desafio de 10(5) promastigotas infectantes de Leishmania (Leishmania) amazonensis na base da cauda. Foram avaliadas a habilidade dessas proteínas em induzir resposta imune e proteção dos animais vacinados após a infecção desafio. Nenhuma diferença estatística foi observada nos níveis de IFN-g nos grupos vacinados em comparação ao grupo controle. Proteção de 28,57; 42,86; 57,14; 42,86; 42,86, 57,14; 42,86; 57,14% foi demonstrado para cada proteína. Abstract in english Immunogenic proteins from nonliving promastigote polyvalent Leishmania vaccine against American tegumentary leishmaniasis (Leishvacin®), produced by Biobrás (Biochemistry of Brazil ), Montes Claros, State of Minas Gerais, Brazil, were identified and purified by polyacrylamide electrophoresis gel and [...] electroelution. C57BL/10 mice were vaccinated with proteins with estimated molecular weights of 42, 46, 63, 66, 73, 87, 97, and 160kDa in three doses of 30µg of each protein at 15-day intervals combined with 250µg of Corynebacterium parvum followed by a challenge infection with 10(5) infective promastigotes from Leishmania (Leishmania) amazonensis. The ability of these proteins to induce immune response and protection was analyzed. No statistical difference was observed in the level of IFN-g induced by proteins in vaccinated groups in comparison with control groups. Six months after challenge infection, protection levels of 28.57; 42.86; 57.14; 42.86; 42.86, 57.14; 42.86 and 57.14% were demonstrated for each purified protein.

Sandra Regina Afonso, Cardoso; João Carlos França da, Silva; Roberto Teodoro da, Costa; Wilson, Mayrink; Maria Norma, Melo; Marilene Suzan Marques, Michalick; Ibrahim Afrânio Willi, Liu; Ricardo Toshio, Fujiwara; Evaldo, Nascimento.

2003-04-01

102

The Leishmania amazonensis TRF (TTAGGG repeat-binding factor homologue binds and co-localizes with telomeres  

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Full Text Available Abstract Background Telomeres are specialized structures at the end of chromosomes essential for maintaining genome stability and cell viability. The importance of telomeric proteins for telomere maintenance has increased our interest in the identification of homologues within the genus Leishmania. The mammalian TRF1 and TRF2 proteins, for example, bind double-stranded telomeres via a Myb-like DNA-binding domain and are involved with telomere length regulation and chromosome end protection. In addition, TRF2 can modulate the activity of several enzymes and influence the conformation of telomeric DNA. In this work, we identified and characterized a Leishmania protein (LaTRF homologous to both mammalian TRF1 and TRF2. Results LaTRF was cloned using a PCR-based strategy. ClustalW and bl2seq sequence analysis showed that LaTRF shared sequence identity with the Trypanosoma brucei TRF (TbTRF protein and had the same degree of sequence similarities with the dimerization (TRFH and the canonical DNA-binding Myb-like domains of both mammalian TRFs. LaTRF was predicted to be an 82.5 kDa protein, indicating that it is double the size of the trypanosome TRF homologues. Western blot and indirect immunofluorescence combined with fluorescence in situ hybridization showed that LaTRF, similarly to hTRF2, is a nuclear protein that also associates with parasite telomeres. Native and full length LaTRF and a mutant bearing the putative Myb-like domain expressed in bacteria bound double-stranded telomeric DNA in vitro. Chromatin immunoprecipitation showed that LaTRF interacted specifically with telomeres in vivo. Conclusion The nuclear localization of LaTRF, its association and co-localization with parasite telomeres and its high identity with TbTRF protein, support the hypothesis that LaTRF is a Leishmania telomeric protein.

Freitas Lucio de H

2010-05-01

103

The 63-kilobase circular amplicon of tunicamycin-resistant Leishmania amazonensis contains a functional N-acetylglucosamine-1-phosphate transferase gene that can be used as a dominant selectable marker in transfection.  

OpenAIRE

Tunicamycin (TM)-resistant Leishmania amazonensis has been found previously to contain amplified chromosomal DNA, existing exclusively as extrachromosomal circles of 63 kb. Fragments of this DNA cloned into plasmids were functionally analyzed by transfection of wild-type cells. A clone with a 15-kb fragment of the 63-kb circle was initially found to confer TM resistance. A library of the 15-kb fragment was then prepared and used in toto to transfect wild-type cells. The transfectants that eme...

Liu, X.; Chang, K. P.

1992-01-01

104

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

Science.gov (United States)

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).

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

2012-08-01

105

LFR1 Ferric Iron Reductase of Leishmania amazonensis Is Essential for the Generation of Infective Parasite Forms*  

OpenAIRE

The protozoan parasite Leishmania is the causative agent of serious human infections worldwide. The parasites alternate between insect and vertebrate hosts and cause disease by invading macrophages, where they replicate. Parasites lacking the ferrous iron transporter LIT1 cannot grow intracellularly, indicating that a plasma membrane-associated mechanism for iron uptake is essential for the establishment of infections. Here, we identify and functionally characterize a second member of the Lei...

Flannery, Andrew R.; Huynh, Chau; Mittra, Bidyottam; Mortara, Renato A.; Andrews, Norma W.

2011-01-01

106

El rol de tres pruebas de ELISA con antígenos de promastigotes de Leishmania braziliensis, L. amazonensis y L. guyanensis en el diagnóstico de leishmaniasis tegumentaria / Role of three ELISA tests using promastigote homogenates of Leishmania braziliensis, L. amazonensis and L. guyanensis in the diagnosis of tegumentary leishmaniasis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Es importante conocer si la variabilidad de especies de Leishmania circulantes en una región afecta la performance de las pruebas de ELISA estandarizadas para el diagnostico de la leishmaniasis. El objetivo de este trabajo fue analizar la reactividad de la prueba de ELISA utilizando homogenados de p [...] romastigotes de Leishmania (V.) braziliensis (ELISAb), L (L) amazonensis (ELISAa) y L (V.) guyanensis (ELISAg) frente a distintos grupos de sueros. Se estudiaron muestras de personas con leishmaniasis cutánea (n = 37), leishmaniasis mucocutánea (n = 8), no infectados (n = 52), infectadas por Trypanosoma cruzi (n = 11) e infecciones mixtas (n = 14). Se calcularon las sensibilidades, especificidades, cut off, valores predictivos, y se compararon las tres pruebas usando ANOVA, índice de concordancia kappa, comparación de curvas ROC e intervalos de confianza construidos por el método de bootstrap. Se encontraron diferencias significativas al comparar los niveles de DO de los sueros de pacientes con leishmaniasis cutánea respecto a los controles negativos, pero no se encontraron diferencias entre pruebas. Las sensibilidades calculadas fueron de 84.6% para ELISAb y ELISAa y de 88.5 para ELISAg, mientras que el valor de especificidad para las tres pruebas fue de 96.2. El índice de concordancia kappa y la comparación de curvas ROC mostraron performances similares para las tres pruebas (p = 0.225). La elevada reactividad obtenida para estas ELISAs frente a sueros de pacientes con leishmaniasis mucocutánea indica un importante potencial de esta técnica como complemento en el diagnóstico de la enfermedad. Abstract in english It is important to know whether the variability of species of Leishmania parasites circulating in a region affects the performance of the ELISA test for the diagnosis of leishmaniasis. Therefore, the aim of this study was to analyze the reactivity of the ELISA using homogenates of promastigotes of L [...] eishmania (V.) braziliensis (ELISAb), Leishmania (L) amazonensis (ELISAa) and Leishmania (V.) guyanensis (ELISAg) against different sera groups. Samples from individuals with cutaneous leishmaniasis (n = 37), mucocutaneous leishmaniasis (n = 8), healthy controls (n = 52), persons infected with Trypanosoma cruzi (n = 11) and mixed infections (n = 14) were included in the study. We calculated sensitivities, specificities, cut offs, and predictive values for the three tests and compared them using ANOVA, kappa index, ROC curves comparison, and confidence intervals calculated by the bootstrap method. Significant differences were found when comparing the OD levels of sera from patients with cutaneous leishmaniasis against healthy controls, but there were no differences when comparing the different ELISAs. The sensitivities calculated for ELISAb and ELISAa were 84.6 and of 88.5% for ELISAg, while the value of specificity for the three tests was 96.2. The kappa index (0.87) and comparison of ROC curves showed similar performance for the three ELISAs (p = 0.225). The high reactivity obtained for these ELISAs in sera of patients with mucocutaneous leishmaniasis indicates this test as an important complement in the diagnosis of the disease.

José F., Gil; Carlos L., Hoyos; Rubén O., Cimino; Alejandro J., Krolewiecki; Inés, Lopéz Quiroga; Silvana P., Cajal; Marisa, Juárez; María F., García Bustos; María C., Mora; Jorge D., Marco; Julio R., Nasser.

2011-10-01

107

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  

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Full Text Available 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, cultivos celulares de macrófagos fueron expuestosa partículas de látex en diferentes proporciones buscando cargas fagocíticas y volúmenes defagosoma semejantes a los de la infección. Las concentraciones de nitrito y parámetros mor-fológicos se midieron a las 48 horas post fagocitosis e infección con 24 horas de activaciónmediante IFN-?y LPS. Se determinó que volúmenes similares de fagosomas generados porpartículas de látex o amastigotes de L. amazonensis, deterioran en la misma proporción laproducción de NO. Esto sugiere que este deterioro no depende de la naturaleza de la partículafagocitada. El incremento en el volumen de fagosoma se correlaciona con la disminución en laproducción de nitrito, por tanto, la expansión del fagosoma puede ser uno de los mecanismosimplicados en la disminución de la producción de NO. Los resultados apoyan la evidencia deque Leishmaniadisminuye la producción de NO pero contradicen la interpretación,comúnmente aceptada, de que este fenómeno es específico de la infección.Leishmaniasis is a parasitic disease caused by a protozoa of the genera Leishmania. Around 12million people are infected and 350 millions of people are risk to contract it. There is evidencethat infection by Leishmania amazonensisdecreases nitric oxide production; it has beeninterpreted that this impairment is induced by the parasite. This study confirmed this idea, butcontradicts that this impairment is exclusive of infection. In this work, cultured macrophageswere exposed to latex beads at diferents proportions, to simulate phagocitic loads andphagosome volumes resembling those of the infection. Nitrite concentration and morphologicalparameters were measured at 48 hours post phagocytosis and infection with 24 hours ofactivation induced by IFN-?and LPS. Our results determined that macrophages with similarvolume of phagosomes generated by latex beads or L. amazonensisamastigotes have the samedecrease in inducible NO production. This suggest that this partial inhibition does not depenton the nature of phagocited particle. Phagosome volume increase correlates with the decreasein inducible NO production. Therefore, phagosome expansion may be one of the mechanismimplicated in the disminution of inducible NO production. The results support the evidencethat Leishmaniareduces inducible NO production, but contradicts the common interpretationthat this fenomena is specific of infection.

Camargo Jiménez Maria Helena

2000-06-01

108

Combining diagnostic procedures for the management of leishmaniasis in areas with high prevalence of Leishmania guyanensis Procedimentos diagnósticos combinados no manejo da leishmaniose em áreas com alta prevalência de Leishmania guyanensis  

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Full Text Available BACKGROUND: The Amazon region corresponds to approximately 40% of the cases of leishmaniasis in Brazil. We report a prospective study with 180 patients conducted in a health care unit that diagnoses 10% of the cases of leishmaniasis in the Brazilian Amazon. The study addresses how a combination of procedures improves diagnosis in areas with high prevalence of Leishmania guyanensis. OBJECTIVES: to evaluate diagnostic methods in areas with high prevalence of Leishmania guyanensis. METHODS: All subjects were amastigote-positive by direct microscopic examination of lesion scarifications. We conducted skin biopsy and histopathology, polymerase chain reaction and parasite cultivation. RESULTS: Polymerase chain reaction detected almost ninety percent of infections when two amplification protocols were used (mini-exon and HSP-70. HSP-70 specific polymerase chain reaction matched the sensitivity of parasite cultivation plus histopathology. CONCLUSION: The best combination was polymerase chain reaction plus histopathology, which increased diagnostic sensitivity to 94%. Species discrimination by polymerase chain reaction disclosed prevalence of human infections with Leishmania guyanensis of 94% and with Leishmania braziliensis of 6% for this regionFUNDAMENTOS: O Amazonas corresponde a aproximadamente 40% dos casos de leishmaniose do país. Nós reportamos um estudo prospectivo com 180 pacientes de uma unidade de saúde que diagnostica 10% dos casos de leishmaniose da amazônia brasileira, com combinação de métodos diagnóstico em área de alta prevalência de Leishmania guyanensis. OBJETIVOS: avaliar métodos diagnóstico da Leishmaniose em área endêmica para Leishmania Amazonensis. MÉTODOS: Todos os pacientes tiveram exame direto positivo com presença de amastigotas. Foi feita também biópsia cutânea, com realização de exame histológico, reação em cadeia da polimerase e cultura. RESULTADO: A reação em cadeia da polimerase detectou aproximadamente 90% de infecção quando foram usados duas técnicas de amplificação (mini-exon and HSP-70. A reação em cadeia da polimerase com HSP-70 foi mais sensível que a cultura associada à histopatologia. CONCLUSÃO: A melhor combinação foi a reação em cadeia da polimerase com histopatologia, com sensibilidade de 94%. A discrimanação das espécies causadoras de infecção humana nessa região mostrou Leishmania guyanensis em 94% dos casos e Leishmania brasiliensis em 6%

Ednelza de Almeida Benicio

2011-12-01

109

Combining diagnostic procedures for the management of leishmaniasis in areas with high prevalence of Leishmania guyanensis / Procedimentos diagnósticos combinados no manejo da leishmaniose em áreas com alta prevalência de Leishmania guyanensis  

Scientific Electronic Library Online (English)

Full Text Available FUNDAMENTOS: O Amazonas corresponde a aproximadamente 40% dos casos de leishmaniose do país. Nós reportamos um estudo prospectivo com 180 pacientes de uma unidade de saúde que diagnostica 10% dos casos de leishmaniose da amazônia brasileira, com combinação de métodos diagnóstico em área de alta prev [...] alência de Leishmania guyanensis. OBJETIVOS: avaliar métodos diagnóstico da Leishmaniose em área endêmica para Leishmania Amazonensis. MÉTODOS: Todos os pacientes tiveram exame direto positivo com presença de amastigotas. Foi feita também biópsia cutânea, com realização de exame histológico, reação em cadeia da polimerase e cultura. RESULTADO: A reação em cadeia da polimerase detectou aproximadamente 90% de infecção quando foram usados duas técnicas de amplificação (mini-exon and HSP-70). A reação em cadeia da polimerase com HSP-70 foi mais sensível que a cultura associada à histopatologia. CONCLUSÃO: A melhor combinação foi a reação em cadeia da polimerase com histopatologia, com sensibilidade de 94%. A discrimanação das espécies causadoras de infecção humana nessa região mostrou Leishmania guyanensis em 94% dos casos e Leishmania brasiliensis em 6% Abstract in english BACKGROUND: The Amazon region corresponds to approximately 40% of the cases of leishmaniasis in Brazil. We report a prospective study with 180 patients conducted in a health care unit that diagnoses 10% of the cases of leishmaniasis in the Brazilian Amazon. The study addresses how a combination of p [...] rocedures improves diagnosis in areas with high prevalence of Leishmania guyanensis. OBJECTIVES: to evaluate diagnostic methods in areas with high prevalence of Leishmania guyanensis. METHODS: All subjects were amastigote-positive by direct microscopic examination of lesion scarifications. We conducted skin biopsy and histopathology, polymerase chain reaction and parasite cultivation. RESULTS: Polymerase chain reaction detected almost ninety percent of infections when two amplification protocols were used (mini-exon and HSP-70). HSP-70 specific polymerase chain reaction matched the sensitivity of parasite cultivation plus histopathology. CONCLUSION: The best combination was polymerase chain reaction plus histopathology, which increased diagnostic sensitivity to 94%. Species discrimination by polymerase chain reaction disclosed prevalence of human infections with Leishmania guyanensis of 94% and with Leishmania braziliensis of 6% for this region

Ednelza de Almeida, Benicio; Ellen Pricilla, Nunes Gadelha; Anette, Talhari; Roberto Moreira da, Silva Jr; Luis Carlos, Ferreira; Mayara Cristina Cordeiro dos, Santos; Marcelo Távora, Mira; Cintia Mara Costa de, Oliveira; Carolina, Talhari; Sinésio, Talhari; Paulo Roberto, Machado; Albert, Schriefer.

1141-11-01

110

Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae Avaliação do PCR na investigação de Leishmania spp em flebotomíneos experimentalmente infectados (Diptera: Psychodidae: Phlebotominae  

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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.Neste trabalho avaliamos o uso da reação em cadeia da polimerase (PCR na investigação da presença de parasitas Leishmania (Kinetoplastida:Trypanosomatidae em flebotomíneos individuais. Para isso, foram utilizados três pares flebotomíneo/parasita: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia migonei/Leishmania amazonensis e Lutzomyia migonei/Leishmania braziliensis, todos eles incriminados na transmissão de leishmaniose cutânea ou visceral. O DNA total a ser amplificado foi extraído de flebotomíneos inteiros, contendo ou não o parasita, sem dissecção prévia do trato digestivo ou combinação de indivíduos. Conteúdos do trato digestivo de flebotomíneos, em especial sangue de camundongo, não interferiram na reação de amplificação. Dez parasitas Leishmania sp. por flebotomíneo foram suficientes para detecção com iniciadores gênero-específicos. Com a utilização de iniciadores para os complexos L. braziliensis e L. mexicana, respectivamente, foi possível discriminar entre L. braziliensis e L. amazonensis, em flebotomíneos infectados experimentalmente (L. migonei.

Érika M. MICHALSKY

2002-10-01

111

Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae) / Avaliação do PCR na investigação de Leishmania spp em flebotomíneos experimentalmente infectados (Diptera: Psychodidae: Phlebotominae)  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste trabalho avaliamos o uso da reação em cadeia da polimerase (PCR) na investigação da presença de parasitas Leishmania (Kinetoplastida:Trypanosomatidae) em flebotomíneos individuais. Para isso, foram utilizados três pares flebotomíneo/parasita: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia [...] migonei/Leishmania amazonensis e Lutzomyia migonei/Leishmania braziliensis, todos eles incriminados na transmissão de leishmaniose cutânea ou visceral. O DNA total a ser amplificado foi extraído de flebotomíneos inteiros, contendo ou não o parasita, sem dissecção prévia do trato digestivo ou combinação de indivíduos. Conteúdos do trato digestivo de flebotomíneos, em especial sangue de camundongo, não interferiram na reação de amplificação. Dez parasitas Leishmania sp. por flebotomíneo foram suficientes para detecção com iniciadores gênero-específicos. Com a utilização de iniciadores para os complexos L. braziliensis e L. mexicana, respectivamente, foi possível discriminar entre L. braziliensis e L. amazonensis, em flebotomíneos infectados experimentalmente (L. migonei). Abstract in english 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 migo [...] nei/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).

Érika M., MICHALSKY; Consuelo L., FORTES-DIAS; Paulo F.P., PIMENTA; Nágila F.C., SECUNDINO; Edelberto S., DIAS.

2002-10-01

112

Cytolytic activity in the genus Leishmania: involvement of a putative pore-forming protein.  

OpenAIRE

We describe here that parasites of the genus Leishmania contain a cytolytic activity which acts optimally at pH 5.0 to 5.5 and at 37 degrees C in vitro. or the four species examined, Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) major presented considerable hemolytic activity, whereas Leishmania (Viannia) panamensis and Leishmania (Viannia) guyanensis showed little and no hemolytic activity, respectively. The cytolytic factor of L. amazonensis promastigotes was characterized...

Noronha, F. S.; Ramalho-pinto, F. J.; Horta, M. F.

1996-01-01

113

The Leishmania amazonensis TRF (TTAGGG repeat-binding factor) homologue binds and co-localizes with telomeres  

OpenAIRE

Abstract Background Telomeres are specialized structures at the end of chromosomes essential for maintaining genome stability and cell viability. The importance of telomeric proteins for telomere maintenance has increased our interest in the identification of homologues within the genus Leishmania. The mammalian TRF1 and TRF2 proteins, for example, bind double-stranded telomeres via a Myb-like DNA-binding domain and are involved with telomere length regulation and chromosome end protection. I...

Freitas Lucio de H; Siqueira-Neto Jair L; de Moraes Camila E; da Silveira Rita de Cássia V; Perez Arina M; da Silva Marcelo S; Cano Maria

2010-01-01

114

Characterisation of a new Leishmania META gene and genomic analysis of the META cluster.  

Science.gov (United States)

The META1 gene of Leishmania is upregulated in metacyclic promastigotes and encodes a 12 kDa virulence-related protein, conserved in all Leishmania species analysed. In this study, the genomic region adjacent to the Leishmania amazonensis META1 gene was characterised and compared to the Leishmania major META1 locus as well as to syntenic loci identified in Trypanosoma brucei and Trypanosoma cruzi. Three new genes expressed with increased abundance of steady state mRNA in L. amazonensis promastigotes were identified, two of which are upregulated in stationary phase promastigotes, sharing the pattern of expression previously described for the META1 mRNA. One of these new genes, named META2, encodes a polypeptide of 444 amino acid residues with a repetitive structure showing three repeats of the META domain (defined as a small domain family found in the Leishmania META1 protein and in bacterial proteins hypothetically secreted and/or implicated in motility) and a carboxyl-terminal region similar to several putative calpain-like proteins of Trypanosoma and Leishmania. PMID:15336424

Ramos, Camila S; Franco, Fernando A L; Smith, Deborah F; Uliana, Silvia R B

2004-09-01

115

Molecular and parasitological detection of Leishmania spp. in a dipteran of the species Tabanus importunus / Detecção molecular e parasitológica de Leishmania spp. em díptero da espécie Tabanus importunus  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese A leishmaniose é uma importante zoonose, de caráter crônico, causada por protozoários do gênero Leishmania spp. Esta protozoose tem como principal vetor os flebotomíneos, sendo que, no Brasil, o Lutzomyia longipalpis é a principal espécie incriminada na transmissão da leishmaniose Visceral Americana [...] . A presença do ácido desoxirribonucleico (DNA) do parasito em ectoparasitos, como carrapatos e pulgas, tem gerado especulações quanto a existência de novos vetores no ciclo da leishmaniose. Foi objetivo deste estudo relatar a detecção molecular de Leishmania spp. em uma mutuca da espécie Tabanus importunus que parasitava um cão oligossintomático infectado por Leishmania spp. A análise molecular amplificou o DNA do protozoário na cabeça, na região torácica e no abdomen do tabanídeo, resultando como positivo para complexo Leishmania. Este é o primeiro relato da presença de DNA de Leishmania spp. em insetos dipteros da espécie T. importunus. Abstract in english Leishmaniasis is an important chronic zoonosis caused by protozoa of the genus Leishmania spp. The major vectors of this protozoosis are sand flies, and Lutzomyia longipalpis is considered the main species implicated in the transmission of American Visceral Leishmaniasis in Brazil. The presence of t [...] he parasite's deoxyribonucleic acid (DNA) in ectoparasites such as ticks and fleas has prompted speculations about the existence of new vectors in the cycle of leishmaniasis. The aim of this paper is to report the molecular detection of Leishmania spp. in a horse fly of the species Tabanus importunus which parasitized an oligosymptomatic dog infected with Leishmania spp. Molecular amplification of the protozoan's DNA in the head, thoracic region and abdomen of the tabanid tested positive for Leishmania complex. This is the first report of the presence of DNA from Leishmania spp. in dipterous insects of the species T. importunus.

Willian Marinho Dourado, Coelho; Katia Denise Saraiva, Bresciani.

2013-12-01

116

Assessment of immunity induced in mice by glycoproteins derived from different strains and species of Leishmania  

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Full Text Available SciELO Brazil | Language: English Abstract in english A comparative study was undertaken on the immunogenic properties of 63kDa glycoproteins obtained from five different strains/species of Leishmania and assessed in C57BL/10 mice. The humoral immune response was assessed by ELISA against the five different antigens of the immunized animals. The cellul [...] ar immune response was derived from Leishmania. The response was found to be species-specific in all of determined by means of the cytokine profiles secreted by the spleen cells of immunized animals. The presence of ³-IFN and IL-2, and the absence of IL-4 in the supernatants of cells stimulated by L. amazonensis antigen established that the cellular response is of Th1 type. The five glycoproteins tested were equally effective in protecting C57BL/10 mice against challenge by L. amazonensis. About 50% of the immunized animals were protected for six months.

Tânia Mara Pinto Dabés, Guimarães; Vicente de Paulo Coelho Peixoto de, Toledo; Carlos Alberto da, Costa; Roberto Teodoro da, Costa; Odair, Genaro; Paul, Williams; Wilson, Mayrink.

1996-02-01

117

Glycosidases in Leishmania and their importance for Leishmania in phlebotomine sandflies with special reference to purification and characterization of a sucrase.  

Science.gov (United States)

Culture forms of Leishmania (Leishmania) amazonensis (IFLA/BR/67/PH8) produce an extracellular enzyme that hydrolyzes sucrose molecules into their component monosaccharides. This is important because phlebotomine sand flies, the invertebrate hosts of Leishmania, ingest plant sap or aphid and coccid honeydew rich in sucrose between blood meals and Leishmania promastigotes cannot uptake sucrose. The sucrase was purified and characterized; its molecular weight, estimated by gel filtration chromatography and SDS-PAGE electrophoresis, was about 73 kDa. K(m) and V(max) measured with sucrose as substrate were respectively 4.4 mM and 6.9 mumole glucose.min-1 (mg sucrase)-1, with maximum pH activity at pH 5.5. A series of natural and p-nitrophenyl-derived substrates were assayed, characterizing the enzyme as a highly specific beta-D-fructofuranoside fructohydrolase. When 11 species of Leishmania and 7 genera of trypanosomatids were screened, only the species of the genus Trypanosoma did not produce an enzyme with saccharolytic activity. These data are in agreement with the fact that the latter vectors do not acquire sucrose or raffinose in their meals. Searching for glycolytic enzymes other than sucrase, we found an N-acetyl-beta-D-galactosaminolytic activity. This N-acetyl-galactosaminidase, here described for the first time, might have a role in peritrophic membrane disruption. The importance of sucrase and N-acetyl-beta-D-galactosaminidase in the Leishmania life cycle is discussed. PMID:8654540

Gontijo, N F; Melo, M N; Riani, E B; Almeida-Silva, S; Mares-Guia, M L

1996-06-01

118

Diagnosis of Leishmania infantum infection by Polymerase Chain Reaction in wild mammals / Diagnóstico de infecção por Leishmania infantum pela reação em cadeia da polimerase em mamíferos silvestres  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A leishmaniose visceral é uma doença infecciosa crônica de mamíferos causada, no Brasil, pelo protozoário Leishmania infantum (sinonímia: Leishmania chagasi) e transmitida pelo flebótomo Lutzomyia longipalpis. Trata-se de uma zoonose endêmica em muitas regiões do Brasil, inclusive em Belo Horizonte, [...] Minas Gerais. Em centros urbanos, leishmaniose visceral acomete principalmente o cão doméstico. Entretanto, L. infantum já foi diagnosticada em outras espécies, incluindo canídeos e primatas de cativeiro em zoológicos. Este estudo buscou avaliar a presença do DNA deste agente em animais de cativeiro e de vida livre da Fundação Zoobotânica de Belo Horizonte através da reação em cadeia da polimerase. Foram analisadas oitenta e uma amostras de sangue oriundas de primatas, carnívoros, ruminantes, edentatos, marsupial e herbívoro de estômago simples. Três primatas Alouatta guariba (bugio marrom) e dois canídeos Speothos venaticus (cachorro-do-mato-vinagre), foram positivos, demonstrando a importância do controle da leishmaniose em áreas endêmicas com a finalidade de conservar a fauna silvestre mantida em cativeiro. Abstract in english Visceral leishmaniasis is a chronic infectious disease caused by Leishmania infantum (synonym: Leishmania chagasi) and transmitted by the sandfly Lutzomyia longipalpis in Brazil. It is an endemic zoonosis in several regions of the country, including Belo Horizonte (State of Minas Gerais). In urban a [...] reas, the domestic dog is susceptible and considered the most important animal reservoir. However, L. infantum has been previously diagnosed in other species, including captive primates and canids. This study aimed to evaluate the presence of the agent DNA in captive animals as well as some free ranging animals from the Zoo-Botanical Foundation of Belo Horizonte by Polymerase Chain Reaction. Eighty one blood samples from primates, carnivores, ruminants, edentates, marsupial, and a monogastric herbivore were analyzed. Three primates Alouatta guariba (brown howler monkey), and two canids Speothos venaticus (bush dog) were positive, demonstrating the importance of leishmaniasis control in endemic areas for preservation of wildlife species in captivity.

Mayara C., Lombardi; Andréia P., Turchetti; Herlandes P., Tinoco; Angela T., Pessanha; Semiramis A., Soave; Marcelo C.C., Malta; Tatiane A., Paixão; Renato L., Santos.

1243-12-01

119

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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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 pelo HIV também apresentavam o DNA de Leishmania (Viannia, detectável no sangue por PCR. A sorologia, pesquisa direta de Leishmania, cultura e PCR de lesões de pele foram negativas. A positividade da PCR não estava associada à contagem de linfócitos T CD4+, doença oportunista, tratamento, uso de inibidores de protease, tatuagem, uso de drogas injetáveis, ambiente da residência ou história prévia de LTA. Os resultados mostraram que indivíduos portadores do vírus HIV que residem em área endêmica podem apresentar o DNA de Leishmania sem manifestar sintomas de LTA. Estes resultados podem ser atribuídos a ação dos medicamentos anti retrovirais que controlam a replicação viral mantendo a integridade do sistema imunológico ou a uma possível atividade anti-Leishmania destas drogas.

Élide Aparecida Oliveira

2011-01-01

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Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae) Avaliação do PCR na investigação de Leishmania spp em flebotomíneos experimentalmente infectados (Diptera: Psychodidae: Phlebotominae)  

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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 whol...

Michalsky, E?rika M.; Fortes-dias, Consuelo L.; Pimenta, Paulo F. P.; Secundino, Na?gila F. C.; Dias, Edelberto S.

2002-01-01

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

OpenAIRE

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 whol...

Michalsky, E?rika M.; Fortes-dias, Consuelo L.; Pimenta, Paulo F. P.; Secundino, Na?gila F. C.; Dias, Edelberto S.

2002-01-01

122

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

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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 brasili [...] enses. 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. Abstract in english 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 tr [...] eatment 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 nine patients (40,9%) of the cohort, the time to healing after initiation of the lesion was calculated as six months of evolution. At twelve months, nineteen patients (86,3%) had complete healing of their lesions. In three patients an active lesion was present for longer than one year. The determinants of this variable natural evolution of human LVB lesion remains completely unknown. It is difficult for us to understand and compare the effects of therapeutic agents in mucocutaneous leishmaniasis.

Jackson Maurício Lopes, Costa; Kyola Costa, Vale; Flávio, França; Ana Cristina R., Saldanha; Joilda Oliveira da, Silva; Ednaldo L., Lago; Philip D., Marsden; Albino V., Magalhães; Conceição de Maria P. e, Silva; Artur, Serra Neto; Clóvis Eduardo S., Galvão.

1990-12-01

123

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

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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 nine patients (40,9% of the cohort, the time to healing after initiation of the lesion was calculated as six months of evolution. At twelve months, nineteen patients (86,3% had complete healing of their lesions. In three patients an active lesion was present for longer than one year. The determinants of this variable natural evolution of human LVB lesion remains completely unknown. It is difficult for us to understand and compare the effects of therapeutic agents in mucocutaneous leishmaniasis.

Jackson Maurício Lopes Costa

1990-12-01

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Estado atual da leishmaniose cutânea difusa (LCD no Estado do Maranhão: II. aspectos epidemiológicos, clínico-evolutivos  

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Full Text Available Os Autores fazem um estudo retrospectivo e prospectivo de 6 pacientes portadores de leishmaniose cutânea difusa, observados no Estado do Maranhão a partir de 1974. Os casos abordados são oriundos de diversas regiões do estado, observando-se em todos eles o envolvimento da leishmania (Leishmania amazonensis, sendo que 5 (84% dos pacientes apresentaram início de doença na 1ª década de vida. Em todos os pacientes envolvidos no estudo, houve relato de lesão inicial nodular única, que, posteriormente, em período variável de tempo, disseminou-se adquirindo outros aspectos. Evolutivamente apresentaram múltiplas lesões nodulares e ulceradas, intradermorreação de Montenegro(- e refratariedade aos esquemas terapêuticos utilizados até ao presente momento.The authors describe a retrospective and prospective study of 6 patients with diffuse cutaneous leishmaniasis observed in the State of Maranhão, since 1974. The patients comefromdifferentruralregions of the state and in all of them Leishmania (Leishmania amazonensis was the cause five of the patients initiated their disease in the first decade of life. All the patients first had a solitary, nodular lesion, that after a variable period of time, disseminated and acquired other aspects. Sequentially the patients presented multiple nodular and ulcerative lesions, negative leishmania skin-lests and a refractory response to the therapeutic schedules used up to the present.

Jackson Maurício Lopes Costa

1992-06-01

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The Diverse and Dynamic Nature of Leishmania Parasitophorous Vacuoles Studied by Multidimensional Imaging  

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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, ...

Real, Fernando; Mortara, Renato A.

2012-01-01

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Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 2. Resposta humoral tissular / Histopathology of mucocutaneous leishmaniasis caused by Leishmania brasiliensis brasiliensis. 2. Tissue humoral response  

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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 presenç [...] a 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. Abstract in english The Authors analysed the humoral response in biopsy material from 90 patients with Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis, utilising the immunoperoxidase method to identify IgA, IgG, IgM, C3 complement fraction and fibrin in the tissue. The presence of IgG, IgA an [...] d IgM was found in tissue plasma cells with a predominance of IgG and this was correlated significantly with the number of plasma cells in the lesion. The presence of immunoglobulins in the tissues stimulated the opsonisation of parasites and/or their antigens resulting in necrosis which represents one of the effective mechanisms to reduce parasite load. In ne- crotic areas and the walls of inflammed vessels immunoglobulins were deposited as well as the C3 fraction of complement and fibrin — immunocomplex fractions derived from the host. This tissue necrosis was interpreted as the result of the action of immunocomplexes in a region with equivalent or a smally excess of antigen (Arthus type reaction). The presence of parasite antigens expressed on the macrophage membrane in the initial phase of the lesion when in contact with tissue immunoglobulins, leads to the installation of an antigen-antibody reaction resulting in the appearance of necrosisin Mucocutaneous Leishmaniasis.

Albino Verçosa de, Magalhães; Mário A. P., Moraes; Alberto N., Raick; Alejandro, Llanos-Cuentas; Jackson M. L., Costa; César C., Cuba; Philip D., Marsden.

1986-10-01

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

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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)

128

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

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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.

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

129

DETECTION OF Leishmania (Viannia) IN Nyssomyia neivai AND Nyssomyia whitmani BY MULTIPLEX POLYMERASE CHAIN REACTION, IN SOUTHERN BRAZIL / Detecção de Leishmania (Viannia) em Nyssomyia neivai e Nyssomyia whitmani por Multiplex Reação em Cadeia da Polimerase, no sul do Brasil  

Scientific Electronic Library Online (English)

Full Text Available Flebotomíneos transmitem os patógenos das leishmanioses. Foi avaliada a infecção natural de flebotomíneos por Leishmania (Viannia) em municípios do Estado do Paraná, sul do Brasil. Os flebotomíneos foram coletados com armadilhas de Falcão e Shannon. Após dissecação para pesquisa de flagelados no tub [...] o digestório e identificação das espécies, as fêmeas de flebotomíneos foram submetidas a Multiplex Reação em Cadeia da Polimerase (multiplex PCR) para a detecção do fragmento do kDNA de Leishmania (Viannia) e do fragmento do gene IVS6 da cacofonia de flebotomíneos. A análise foi realizada em pools contendo sete a 12 tubos digestórios de fêmeas da mesma espécie. Um total de 510 fêmeas foram analisadas, incluindo nove Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai e 268 Nyssomyia whitmani. Embora nenhuma fêmea tenha sido encontrada naturalmente infectada com flagelados pela dissecação, o fragmento de DNA de Leishmania (Viannia) foi mostrado por multiplex PCR em uma amostra de Ny. neivai (0,46%) e três amostras de Ny. whitmani (1,12%). Conclui-se que Ny. neivai e Ny. whitmani são suscetíveis à infecção por Leishmania, e que multiplex PCR, devido à sua sensibilidade, especificidade e viabilidade, pode ser utilizada em estudos epidemiológicos para a detecção da infecção natural do inseto vetor. Abstract in english Sandflies transmit pathogens of leishmaniasis. The natural infection of sandflies by Leishmania (Viannia) was assessed in municipalities, in the state of Paraná, in Southern Brazil. Sandflies were collected with Falcão and Shannon traps. After dissection in search of flagellates in digestive tubes a [...] nd identification of the species, female sandflies were submitted to the Multiplex Polymerase Chain Reaction (multiplex PCR) for detection of the fragment of the kDNA of Leishmania (Viannia) and the fragment from the IVS6 cacophony gene region of the phlebotomine insects. The analysis was performed in pools containing seven to 12 guts from females of the same species. A total of 510 female sandflies were analyzed, including nine Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai, and 268 Nyssomyia whitmani. Although none of the females was found naturally infected by flagellates through dissection, the fragment of DNA from Leishmania (Viannia) was shown by multiplex PCR in one sample of Ny. neivai (0.46%) and three samples of Ny. whitmani (1.12%). It was concluded that Ny. neivai and Ny. whitmani are susceptible to Leishmania infection, and that multiplex PCR can be used in epidemiological studies to detect the natural infection of the sandfly vector, because of its sensitivity, specificity and feasibility.

Herintha Coeto, Neitzke-Abreu; Kárin Rosi, Reinhold-Castro; Mateus Sabaini, Venazzi; Regiane Bertin de Lima, Scodro; Alessandra de Cassia, Dias; Thaís Gomes Verzignassi, Silveira; Ueslei, Teodoro; Maria Valdrinez Campana, Lonardoni.

2014-09-01

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Characterization of Leishmania infantum species in dogs from the urban area of Cuiabá, State of Mato Grosso, Brazil / Caracterização da espécie Leishmania infantum em cães de área urbana de Cuiabá, Estado do Mato Grosso  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: A leishmaniose visceral apresenta comportamento urbano em algumas cidades brasileiras, sendo os cães domésticos as principais fontes de infecção. Em Cuiabá-MT, a leishmaniose visceral canina foi diagnosticada e caracterizada, como recomendação do Ministério da Saúde. MÉTODOS: Amostras bi [...] ológicas de cães suspeitos foram analisadas por eletroforese de isoenzimas. Foram utilizadas a enzima 6PGDH e a cepa de referência IOC/L0566 (MHOM/BR/1975/M2903) de Leishmania (Leishmania) infantum, como um dos controles. RESULTADOS: A análise eletroforética revelou que os isolados pertenciam à espécie L. (L.) infantum. CONCLUSÕES: Os autores ressaltam a importância da caracterização da espécie, principalmente em cidades com infecção mista, como Cuiabá. Abstract in english INTRODUCTION: Visceral leishmaniasis presents urban behavior in some Brazilian cities, with domestic dogs as the main infection source. In Cuiabá, MT, canine visceral leishmaniasis was diagnosed and characterized as recommended by the Ministry of Health. METHODS: Biological samples from suspected ca [...] nine carriers were analyzed by the isoenzyme electrophoresis technique. The 6PGDH enzyme and reference strain IOC/L0566 (MHOM/BR/1975/M2903) of Leishmania (Leishmania) infantum was used as one of the controls. RESULTS: Electrophoresis analysis revealed that the canine isolates belonged to the species L. (L.) infantum. CONCLUSIONS: The authors emphasize the importance of species characterization, particularly in areas of mixed infection like Cuiabá.

Bianca De, Santis; Elizabeth Gloria Oliveira Barbosa, Santos; Elisa, Cupolillo; Renato, Porrozzi; Amanda dos Santos, Cavalcanti; Bárbara Neves dos, Santos; Saulo Teixeira De, Moura; Kellen, Malhado; Sergio Augusto Miranda, Chaves.

2011-12-01

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Characterization of Leishmania infantum species in dogs from the urban area of Cuiabá, State of Mato Grosso, Brazil Caracterização da espécie Leishmania infantum em cães de área urbana de Cuiabá, Estado do Mato Grosso  

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Full Text Available INTRODUCTION: Visceral leishmaniasis presents urban behavior in some Brazilian cities, with domestic dogs as the main infection source. In Cuiabá, MT, canine visceral leishmaniasis was diagnosed and characterized as recommended by the Ministry of Health. METHODS: Biological samples from suspected canine carriers were analyzed by the isoenzyme electrophoresis technique. The 6PGDH enzyme and reference strain IOC/L0566 (MHOM/BR/1975/M2903 of Leishmania (Leishmania infantum was used as one of the controls. RESULTS: Electrophoresis analysis revealed that the canine isolates belonged to the species L. (L. infantum. CONCLUSIONS: The authors emphasize the importance of species characterization, particularly in areas of mixed infection like Cuiabá.INTRODUÇÃO: A leishmaniose visceral apresenta comportamento urbano em algumas cidades brasileiras, sendo os cães domésticos as principais fontes de infecção. Em Cuiabá-MT, a leishmaniose visceral canina foi diagnosticada e caracterizada, como recomendação do Ministério da Saúde. MÉTODOS: Amostras biológicas de cães suspeitos foram analisadas por eletroforese de isoenzimas. Foram utilizadas a enzima 6PGDH e a cepa de referência IOC/L0566 (MHOM/BR/1975/M2903 de Leishmania (Leishmania infantum, como um dos controles. RESULTADOS: A análise eletroforética revelou que os isolados pertenciam à espécie L. (L. infantum. CONCLUSÕES: Os autores ressaltam a importância da caracterização da espécie, principalmente em cidades com infecção mista, como Cuiabá.

Bianca De Santis

2011-12-01

132

Padronização de condições para detecção de DNA de Leishmania spp. em flebotomíneos (Diptera, Psychodidae pela reação em cadeia da polimerase Standardization of conditions for PCR detection of Leishmania spp. DNA in sand flies (Diptera, Psychodidae  

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Full Text Available A correta identificação dos agentes etiológicos em insetos vetores é de crucial importância aos estudos epidemiológicos. A pesquisa de flagelado nesses vetores, pela dissecção de seu trato digestivo, observação microscópica do seu conteúdo ou por isolamento dos parasitas provenientes de insetos em meios de cultura, tem-se mostrado operacionalmente inadequada e com baixa especificidade do diagnóstico, pois fêmeas de flebotomíneos também podem albergar outros flagelados como Trypanosoma e Endotrypanum. Acreditamos que por sua eficiência e especificidade, a amplificação de seqüências-alvo do DNA da Leishmania, por meio da reação em cadeia de polimerase, pode ser aplicada na investigação de sua presença em flebotomíneos, desde que estes estejam devidamente acondicionados e o DNA do parasita extraído a partir de metodologia adequada. Este trabalho descreve metodologias utilizadas na padronização da conservação dos espécimes de flebotomíneos e extração do DNA da Leishmania como uma alternativa mais prática que os métodos tradicionais.The correct identification of etiological agents in vector insects is crucial for epidemiological studies. Identification of flagellates in such vectors, usually by dissection of the digestive tract and microscopic observation of the contents as well as attempts at parasite isolation from insects in culture media, have proven operationally inadequate and with poor diagnostic specificity, since female sand flies are also hosts for other flagellates like Trypanosoma and Endotrypanum. Due to the efficiency and specificity of DNA target sequence amplification by polymerase chain reaction (PCR, the latter could be used to investigate the presence of Leishmania in sand flies, although the insects need to be properly stored and the Leishmania DNA extracted using appropriate methodology. This paper describes methodologies to standardize sand fly storage and Leishmania DNA extraction in such specimens as a more practical method in field studies.

Byanca Regina de Paiva

2007-01-01

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LA Leishmania spp. COMO ESTRATEGIA DE DIAGNÓSTICO Y TRATAMIENTO DE LA LeishmaniaSIS, UN ARTÍCULO DE REVISIÓN / Leishmania spp. AS A DIAGNOSTIC STRATEGY AND AS A TREATMENT OF LeishmaniaSIS; AN ARTICLE OF REVISION. / A Leishmania spp. COMO ESTRATÉGIA DE DIAGNÓSTICO E TRATAMIENTO DA LeishmaniaSIS, UM ARTIGO DE REVISÃO  

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Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese Algumas enfermidades emergentes e reemergentes têm aumentado de maneira quase indecifrável, quanto ao lugar de origem. Tais são os casos do Mal de Chagas, malária, dengue, febre amarela, raiva e leishmaniose, devido entre outros, a fatores de mobilidade populacional, demográficos, sociais e econômic [...] os que levam microrganismos a gerarem adaptações ao meio mutante, dificultando seu diagnóstico e tratamento por métodos convencionais. Métodos Realizou-se uma busca exaustiva nas bases de dados relacionadas com genômica e proteômica, como o NCBI (National Center for Biotechnology Information), auspiciada pela U.S National Library of Medicine e o National Institute of Health, onde se conta com aceso a PubMed. Resultados Na atualidade aplicam-se técnicas de marcadores moleculares, PCR (Reação em cadeia da polimerasa) que complementam as provas bioquímicas e microbiológicas empregadas comumente no diagnóstico. Conhecendo a expressão genômica destes parasitas, se poderão desenhar métodos novos mais efetivos contra cepas resistentes aos fármacos disponíveis na atualidade e de prevenção rápida. Conclusões Neste artigo se apresenta uma revisão bibliográfica, onde a informação clínica do paciente é determinante para o diagnóstico, o qual pode ser confirmado com técnicas moleculares desenvolvidas em tempo real, para contribuir ao conhecimento molecular da Leishmania spp, como estratégia de diagnóstico e tratamento desta patologia. Abstract in spanish Introducción: Algunas enfermedades emergentes y reemergentes han venido en aumento de manera casi impredecible, en cuanto al sitio de origen. Tal es el caso de la enfermedad de Chagas, malaria, dengue, fiebre amarilla, rabia, Leishmaniasis, debido entre otros a factores de movilidad poblacional, dem [...] ográficos, sociales y económicos que han llevado a que los microorganismos generen adaptaciones al medio cambiante, dificultando su diagnóstico y tratamiento por métodos convencionales. Métodos: Se realizó una búsqueda exhaustiva en las bases de datos relacionadas con genómica y proteómica como el NCBI (National Center for Biotechnology Information), auspiciado por la U.S National Library of Medicine y el National Institute of Health, donde se cuenta con acceso a PubMed Resultados: En la actualidad se han venido aplicando técnicas de marcadores moleculares, PCR (Reacción en Cadena de la Polimerasa) que complementan las pruebas bioquímicas y microbiológicas empleadas comúnmente en el diagnóstico. Conociendo la expresión genómica de estos parásitos, se podrán diseñar métodos nuevos más efectivos contra cepas resistentes a los fármacos disponibles en la actualidad y de prevención temprana. Conclusiones: En este artículo se presenta una revisión bibliográfica, donde la información clínica del paciente es determinante para el diagnóstico, el cual puede ser confirmado con técnicas moleculares desarrolladas en tiempo real, para aportar al conocimiento molecular de la Leishmania spp, como estrategia de diagnóstico y tratamiento de esta patología. Abstract in english Introduction: Some emerging and reemerging infirmities have been increasing in an almost unpredictable manner as far as site of origin. Such is the case with such diseases as Chagas, malaria, dengue, yellow fever, rabies, and Leishmaniasis. Various demographic, social, and economic factors, as well [...] as population mobility have allowed microorganisms to generate adaptations to changing environments and thus make diagnosis and treatment by conventional methods more difficult. Methodology: An exhaustive search was undertaken in the data bases related to genome and protein sequence information found at the NCBI (National Center for Biotechnology Information), part of the United States National Library of Medicine and the National Institutes of Health, all with direct access to PubMed. Results: Today techniques using molecular markers, PCR (Polymerase Chain Reaction), are being

Martha Cecilia, Beltrán Cifuentes; Patricia, Durán Ospina; Luisa Fernanda, Corredor Arias.

2007-09-01

134

Immunogold labeling and cerium cytochemistry of the enzyme ecto-5'-nucleotidase in promastigote forms of Leishmania species  

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Full Text Available We have applied both enzyme cytochemistry and immunological labeling techniques to characterize the enzyme 5'-nucleotidase (5'-Nase, at the ultrastructural level, in promastigote forms of four Leishmania species: Leishmania amazonensis, Leishmania mexicana, Leishmania donovani and Leishmania chagasi. The cerium phosphate staining was localized at the surface of the cell body, the flagellum and the flagellar pocket membranes of all the parasites studied. The immunogold labelling technique confirmed these results. In this report we localized 5'-Nase in L. chagasi and L. amazonensis which have been implicated respectively in visceral and cutaneous forms of leishmaniasis. In addition, we confirmed the localization of this phosphomonoesterase in the other two species studied. The superior quality of the images, obtained with both methodologies, confirms that these parasites possess mechanisms capable of hydrolyzing nucleotide monophosphates, and that the expression of 5'-Nase is associated with the outer surface of the plasma membrane.

Suzana Corte-Real

1993-09-01

135

Immunogold labeling and cerium cytochemistry of the enzyme ecto-5'-nucleotidase in promastigote forms of Leishmania species  

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Full Text Available SciELO Brazil | Language: English Abstract in english We have applied both enzyme cytochemistry and immunological labeling techniques to characterize the enzyme 5'-nucleotidase (5'-Nase), at the ultrastructural level, in promastigote forms of four Leishmania species: Leishmania amazonensis, Leishmania mexicana, Leishmania donovani and Leishmania chagas [...] i. The cerium phosphate staining was localized at the surface of the cell body, the flagellum and the flagellar pocket membranes of all the parasites studied. The immunogold labelling technique confirmed these results. In this report we localized 5'-Nase in L. chagasi and L. amazonensis which have been implicated respectively in visceral and cutaneous forms of leishmaniasis. In addition, we confirmed the localization of this phosphomonoesterase in the other two species studied. The superior quality of the images, obtained with both methodologies, confirms that these parasites possess mechanisms capable of hydrolyzing nucleotide monophosphates, and that the expression of 5'-Nase is associated with the outer surface of the plasma membrane.

Suzana, Corte-Real; Renato, Porrozzi; Maria de Nazareth Leal de, Meirelles.

1993-09-01

136

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

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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. PMID:22348167

Real, Fernando; Mortara, Renato A

2012-01-01

137

Estudo evolutivo da leishmaniose mucosa (7 a 17 anos de seguimento) causada por Leishmania (Viannia ) braziliensis em Três Braços, Bahia  

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Full Text Available No período de agosto a dezembro de 1993 realizou-se um levantamento de 77 pacientes da casuística de leishmaniose mucosa do programa de Três Braços, registrada no período de 1976 a 1986. Encontrou-se 65 pacientes vivos e 12 falecidos. Os primeiros foram submetidos a exame clínico geral e otorrinolar [...] ingológico e à pesquisa de anticorpos por imunofluorescência indireta. Os pacientes com lesões ativas foram submetidos à biópsia da mucosa nasal para isolar o parasita em meio de cultura NNN a partir da inoculação direta do material ou das lesões desenvolvidas no hamster e para estudo histopatológico. Todos os isolados foram caracterizados como Leishmania (Viannia) braziliensis utilizando anticoipos monoclonais. Cinqüenta e seis (86%) pacientes estavam curados e nove (13%) encontravam-se com lesões ativas. Entre os pacientes falecidos, cinco (41%) estavam curados no momento do óbito. O programa teve 79% de pacientes curados ao longo de 17 anos. O tempo médio de seguimento clínico foi de 10 anos (7-17 anos). A doença como causa-mortis foi sugerida em 3 casos. Abstract in english Seventy seven (68%) patients with mucosal leishmaniasis recorded during the period 1976- 1986 in the region of Três Braços, Bahia were traced and re-evaluated clinically, diagnostically and therapeutically. Sixty-five patients were alive. The families of 12 dead patients were interviewed about proba [...] ble cause of death. The 65 patients had a fresh clinical examination supplemented when necessary by a skilled ENT examination. All had a titre of circulating immunofluorescent antibodies estimated at the time. Eight patients with active mucosal lesions had triturated biopsies which were cultivated in NNN medium and inoculated in hamsters to attempt to recover Leishmania. The isolates were identified by monoclonal antibodies as Leishmania (Viannia) braziliensis. Fifty-six (86%) patients were judged clinically cured. Nine (13%) bad active lesions. Of the 12 patients who died 5 (41%) had no signs of activity at death. Mucosal leishmaniasis was thought to be the direct cause of death in 3 patients. The field treatment programme at Três Braços has managed to clinically cure 61 patients (79%) during 17 years. Follow-up periods were a mean of 10 years (range 7-17).

Maria Regina Fernandes de, Oliveira; Vanize de Oliveira, Macêdo; Edgar Marcelino de, Carvalho; Aldina, Barral; Jaqueline Guerreiro, Marotti; Achiléa, Bittencourt; Maria Virgínia Avelar de, Abreu; Maria de La Glória, Orge Orge; Hélio de Andrade, Lessa; Philip Davis, Marsden.

1995-12-01

138

An agent-based model for Leishmania major infection  

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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].

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

139

Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis  

OpenAIRE

FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA) ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respostas terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia) guyanensis. MÉTODOS: 185 pacientes foram...

Leandro Ourives Neves; Anette Chrusciak Talhari; Ellen Priscilla Nunes Gadelha; Roberto Moreira da Silva Júnior; Jorge Augusto de Oliveira Guerra; Luiz Carlos Lima Ferreira; Sinésio Talhari

2011-01-01

140

Avaliação da atividade anti-Trypanosoma e anti-Leishmania de Mentha arvensis e Turnera ulmifolia  

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Full Text Available Tripanosomiasis or "Chagas disease", caused by Trypanosoma cruzi, affect 10 million people in Latin America. Today, the chemotherapy is the only specific treatment against this disease, being the most used drugs the nifurtimox and benznidazole. Leishmaniasis is a disease caused by parasites of the genus Leishmania, mainly founded in regions with forests, as the Amazonia. Recent reports about the Leishmaniasis indicate a deficit of therapeutical drugs available against this disease and reinforce the necessity of the discovering of new drugs. An interesting approach against these diseases is the use of natural products, as the extracts of plants as Mentha arvensis and Turnera ulmifolia. For the in vitro assays against T. cruzi and Leishmania, was used the clone CL-B5 and promastigote forms, respectively. The cytotoxic assay was performed using fibroblasts. Our results indicated that M. arvensis was active against all strains assayed, inhibiting 65 e 47% of the assayed strains (IC50 = 192.3 and 531.9 ¿g/mL respectively, representing an interesting and alternative source of natural products with anti-kinetoplastida activity.

Karla K.A. SANTOS

2012-01-01

141

Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population / Prevalência da infecção por Trypanosoma cruzi e Leishmania chagasi e fatores de risco numa população indígena da Colômbia  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este estudo foi realizado para obter a linha de base da epidemiologia da Leishmaniose Visceral Americana e da Doença de Chagas numa comunidade indígena, onde o governo está desenvolvendo um programa de melhoramento da habitação. A coleta de dados referentes aos fatores sócio-econômicos e do meio amb [...] iente associados ao risco de transmissão de Leishmania chagasi e Trypanosoma cruzi foi feita por meio de respostas a questionário endereçado aos componentes acima mencionados. O inquérito foi realizado em 242 unidades domiciliárias (1440 indivíduos). Foi realizada a prova de Montenegro em 385 indivíduos e colhidas 454 amostras de sangue em papel de filtro, para pesquisar o teor de anticorpos contra L. chagasi por meio das técnicas de ELISA e IFI e o teor de anticorpos contra T. cruzi por meio de ELISA. A prevalência sorológica foi de 8,7% para T. cruzi, 4,6% e 5,1% para L. chagasi por meio de IFI e ELISA, respectivamente. Ao se comparar estas duas provas foi encontrado que por meio de ELISA a sensibilidade e especificidade para detecção de anticorpos contra L. chagasi foi de 57% e 97% respectivamente. Os resultados da intradermo-reação de Montenegro revelaram uma positividade de 19%. Os resultados dos três testes de imunodiagnóstico mostraram uma prevalência da infecção por L. chagasi de 17,1%. Além disso, 2,7% da população estudada apresentou reações sorológicas positivas para os dois parasitos, evidenciando uma possível reação cruzada. A soropositividade para L. chagasi e T. cruzi aumentou com a idade, e não houve associação com o gênero. Idade (p Abstract in english This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas’ Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 peopl [...] e), by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was applied to 385 people and 454 blood samples were collected on filter paper in order to detect L. chagasi antibodies by ELISA and IFAT and T. cruzi antibodies by ELISA. T. cruzi seroprevalence was 8.7% by ELISA, L. chagasi was 4.6% and 5.1% by IFAT and ELISA, respectively. ELISA sensitivity and specificity for L. chagasi antibodies were 57% and 97.5% respectively, as compared to the IFAT. Leishmanin skin test positivity was 19%. L. chagasi infection prevalence, being defined as a positive result in the three-immunodiagnostic tests, was 17.1%. Additionally, 2.7% of the population studied was positive to both L. chagasi and T. cruzi, showing a possible cross-reaction. L. chagasi and T. cruzi seropositivity increased with age, while no association with gender was observed. Age (p

Augusto, CORREDOR ARJONA; Carlos Arturo, ALVAREZ MORENO; Carlos Alberto, AGUDELO; Martha, BUENO; Myriam Consuelo, LÓPEZ; Elvia, CÁCERES; Patricia, REYES; Sofia, DUQUE BELTRAN; Luis Eduardo, GÜALDRON; Maria Mercedes, SANTACRUZ.

1999-07-01

142

BODY WEIGHT AS A DETERMINANT OF CLINICAL EVOLUTION IN HAMSTERS (Mesocricetus auratus) INFECTED WITH Leishmania (Viannia) panamensis / Peso como determinante da evolução clínica em hamsters (Mesocricetus auratus) infectados com Leishmania (Viannia) panamensis  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese RESUMO O resultado clínico da infecção por espécies de Leishmania do subgênero Viannia no modelo de hamster (Mesocricetus auratus) tem se mostrado diferente, dependendo do protocolo experimental. O peso corporal tem sido um importante determinante da evolução clínica da infecção em hamsters com lei [...] shmaniose visceral, mas sua importância como parâmetro clínico em hamsters com leishmaniose cutânea não é conhecido. Neste estudo, a evolução clínica da infecção com L. (V) panamensis foi avaliada em jovens e adultos hamsters machos durante 11 semanas, comparando os parâmetros clínicos tais como a atitude, a temperatura, a frequência respiratória, a aparência das fezes, e o peso corporal entre infectado e grupos não infectados. Os resultados mostraram que o peso corporal diminuiu em hamsters adultos após infecção por L. (V) panamensis. Esta observação suporta a utilização do peso corporal, como um parâmetro adicional para definir a administração ou o tratamento de leishmaniose cutânea em hamsters adultos infectados usados como modelo animal experimental para a leishmaniose. Abstract in english SUMMARY The clinical outcome of infection with Leishmania species of the subgenus Viannia in hamster model (Mesocricetus auratus) has shown to be different depending on experimental protocol. Body weight has been a relevant determinant of the clinical outcome of the infection in hamsters with visce [...] ral leishmaniasis but its importance as a clinical parameter in hamsters with cutaneous leishmaniasis is not known. In this study, the clinical evolution of infection with L. (V) panamensis was evaluated in juvenile and adult male hamsters during 11 weeks by comparing clinical parameters such as attitude, temperature, respiratory rate, appearance of the stool, and body weight between infected and non-infected groups. Results showed that body weight decreased in adult hamsters after infection by L. (V) panamensis; this observation supports the use of body weight as an additional parameter to define the management or treatment of cutaneous leishmaniasis in infected adult hamsters used as an animal experimental model for leishmaniasis.

Angela Maria, Gomez-Galindo; Lucy Gabriela, Delgado-Murcia.

2013-09-01

143

Tentativa de transmissão da Leishmania donovani pela picada do Lutzomyia longipalpis entre cães / Attempts to transmit L. donovani from dog to dog by the bite of Lutzomyia longipalpis  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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. [...] Abstract in english In 1958, attempts were made to transmit Leishmania donovani (Leveran & Mensnil) from dog to dog by the bite of Lutzomya longipalpis (Lutz & Neiva) in the State of Ceará, Brazil. Two young, healthy dogs (2-3 months old) were bitten by 31 laboratory reared sanflies fed previously on infected dogs; nin [...] e of the sandflies were later found to be infected with L. donovani, but none of the healthy dogs on which they fed became infected.

Ítalo A., Sherlock; Vilmia A., Sherlock.

1972-02-01

144

Estado atual da leishmaniose cutânea difusa (LCD) no Estado do Maranhão: II. aspectos epidemiológicos, clínico-evolutivos  

Scientific Electronic Library Online (English)

Full Text Available Os Autores fazem um estudo retrospectivo e prospectivo de 6 pacientes portadores de leishmaniose cutânea difusa, observados no Estado do Maranhão a partir de 1974. Os casos abordados são oriundos de diversas regiões do estado, observando-se em todos eles o envolvimento da leishmania (Leishmania) ama [...] zonensis, sendo que 5 (84%) dos pacientes apresentaram início de doença na 1ª década de vida. Em todos os pacientes envolvidos no estudo, houve relato de lesão inicial nodular única, que, posteriormente, em período variável de tempo, disseminou-se adquirindo outros aspectos. Evolutivamente apresentaram múltiplas lesões nodulares e ulceradas, intradermorreação de Montenegro(-) e refratariedade aos esquemas terapêuticos utilizados até ao presente momento. Abstract in english The authors describe a retrospective and prospective study of 6 patients with diffuse cutaneous leishmaniasis observed in the State of Maranhão, since 1974. The patients comefromdifferentruralregions of the state and in all of them Leishmania (Leishmania) amazonensis was the cause five of the patien [...] ts initiated their disease in the first decade of life. All the patients first had a solitary, nodular lesion, that after a variable period of time, disseminated and acquired other aspects. Sequentially the patients presented multiple nodular and ulcerative lesions, negative leishmania skin-lests and a refractory response to the therapeutic schedules used up to the present.

Jackson Maurício Lopes, Costa; Ana Cristina Rodrigues, Saldanha; Ana Carla de Melo e, Silva; Artur, Serra Neto; Clovis Eduardo Santos, Galvão; Conceição de Maria Pedroso e, Silva; Antonio Rafael da, Silva.

1992-06-01

145

Lectin-binding properties of different Leishmania species.  

Science.gov (United States)

Carbohydrate cell-surface residues on stationary promastigotes of 19 isolates of Leishmania were studied with a panel of 27 highly purified lectins, which were specific for N-acetyl-D-glucosamine, D-mannose, L-fucose, D-galactose, N-acetyl-D-galactosamine, and sialic acid. The specificity of the cell-surface carbohydrates was analyzed by agglutination and radioiodinated lectin-binding assays. L. (L.) amazonensis and L. (L.) donovani were agglutinated by 12 and 10 of the 27 lectins used, respectively. Artocarpus integrifolia lectin (Jacalin) was incapable of agglutinating the tested species of the donovani complex, and this result was confirmed by radioiodinated Jacalin-binding assays. Jacalin had an average of 3.8 x 10(6) receptors/L. (L) amazonensis promastigote and bound with an association constant of 5 x 10(6) M(-1). PMID:10382607

Andrade, A F; Saraiva, E M

1999-07-01

146

Leishmania metacyclogenesis is promoted in the absence of purines.  

Science.gov (United States)

Leishmania parasites, the causative agent of leishmaniasis, are transmitted through the bite of an infected sand fly. Leishmania parasites present two basic forms known as promastigote and amastigote which, respectively, parasitizes the vector and the mammalian hosts. Infection of the vertebrate host is dependent on the development, in the vector, of metacyclic promastigotes, however, little is known about the factors that trigger metacyclogenesis in Leishmania parasites. It has been generally stated that "stressful conditions" will lead to development of metacyclic forms, and with the exception of a few studies no detailed analysis of the molecular nature of the stress factor has been performed. Here we show that presence/absence of nucleosides, especially adenosine, controls metacyclogenesis both in vitro and in vivo. We found that addition of an adenosine-receptor antagonist to in vitro cultures of Leishmania amazonensis significantly increases metacyclogenesis, an effect that can be reversed by the presence of specific purine nucleosides or nucleobases. Furthermore, our results show that proliferation and metacyclogenesis are independently regulated and that addition of adenosine to culture medium is sufficient to recover proliferative characteristics for purified metacyclic promastigotes. More importantly, we show that metacyclogenesis was inhibited in sand flies infected with Leishmania infantum chagasi that were fed a mixture of sucrose and adenosine. Our results fill a gap in the life cycle of Leishmania parasites by demonstrating how metacyclogenesis, a key point in the propagation of the parasite to the mammalian host, can be controlled by the presence of specific purines. PMID:23050028

Serafim, Tiago Donatelli; Figueiredo, Amanda Braga; Costa, Pedro Augusto Carvalho; Marques-da-Silva, Eduardo Almeida; Gonçalves, Ricardo; de Moura, Sandra Aparecida Lima; Gontijo, Nelder Figueiredo; da Silva, Sydnei Magno; Michalick, Marilene Suzan Marques; Meyer-Fernandes, José Roberto; de Carvalho, Roberto Paes; Uliana, Silvia Reni Bortolin; Fietto, Juliana Lopes Rangel; Afonso, Luís Carlos Crocco

2012-01-01

147

Leishmania infection in a population of dogs: an epidemiological investigation relating to visceral leishmaniasis control / Infecção por Leishmania em uma população de cães: uma investigação epidemiológica relacionada ao controle da leishmaniose visceral  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A identificação dos fatores associados à infecção por Leishmania em cães é essencial para o direcionamento das ações de controle da leishmaniose visceral. Desta forma, o presente estudo analisa alguns destes fatores em uma população de cães, bem como as limitações das estratégias de controle executa [...] das em um município brasileiro. Por meio de modelos de regressão logística, analisou-se a associação entre as variáveis de exposição e a ocorrência de infecção. As ações de controle da doença foram analisadas qualitativamente. Dos 755 animais avaliados por meio de sorologia, 13,6% (103/755) foram soro-reagentes. Destes, 23,3% (24/103) eram assintomáticos e 76,7% (79/103) apresentaram pelo menos um sinal clínico possivelmente associado com a leishmaniose visceral. Com associações fracas, cães de raça pura, de pelo curto, com mais de cinco anos, machos e de grande porte foram mais propensos à infecção. As duas últimas variáveis compuseram o modelo final de regressão, sendo significativa a associação com o tamanho do cão. As estratégias de controle desenvolvidas apresentaram limitações e um número elevado de cães sorologicamente negativos foi submetido a eutanásia. Os dados apresentados contribuem para um melhor entendimento da dinâmica da infecção na leishmaniose visceral canina e indicam que ações visando a adequada execução do programa de controle da doença em áreas endêmicas brasileiras devem ser priorizadas. Abstract in english Identification of factors associated with Leishmania infection in dogs is essential for targeting visceral leishmaniasis control actions. Thus, the present study analyzed some of these factors in a population of dogs in a Brazilian municipality, along with the limitations of control strategies imple [...] mented there. The association between the exposure variables and occurrences of infection was analyzed through logistic regression models. The disease control interventions were treated qualitatively. Out of the 755 animals examined, 13.6% (103/755) were seropositive. Of these, 23.3% (24/103) were asymptomatic and 76.7% (79/103) presented at least one clinical sign possibly associated with visceral leishmaniasis. With weak associations, purebred, shorthaired, over 5 years of age, male and large dogs were more prone to infection. The latter two variables formed the final regression model and the association with dog size was statistically significant. The control strategies developed presented limitations and a great number of seronegative dogs was culled. The data presented contribute towards better understanding of the dynamics of infection in canine visceral leishmaniasis and indicate that actions aimed towards adequate implementation of Visceral Leishmaniasis control program in Brazilian endemic areas should be prioritized.

Klauber Menezes, Penaforte; Vinicius Silva, Belo; Rafael Goncalves, Teixeira-Neto; Renata Aparecida Nascimento, Ribeiro; Robson Bruniera de, Oliveira; Dante Alighieri, Schettini; Eduardo Sergio da, Silva.

2013-12-01

148

Avaliação do teste de aglutinação direta na detecção da infecção por Leishmania (Viannia braziliensis em possíveis reservatórios de leishmaniose tegumentar americana no estado do Ceará  

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Full Text Available Com o objetivo de avaliar a aplicabilidade do Teste de Aglutinação Direta (TAD como método de detecção da infecção natural canina por Leishmania (Viannia braziliensis, foi realizado um estudo envolvendo soros de cães residentes em uma área endêmica de leishmaniose tegumentar, Serra de Baturité, CE e soros de cães provenientes da cidade de Curitiba, PR, área não endêmica de leishmaniose. Os resultados obtidos com o TAD neste trabalho indicam a possibilidade do uso deste teste sorológico para levantamentos epidemiólogicos da infecção em reservatórios; neste estudo, o cão doméstico.In order to evaluate the aplicability of the Direct Agglutination Test (DAT as a method of detection of the natural canine infection for Leishmania (Viannia braziliensis, it was realized a study involving the serum of naive dogs from Serra de Baturite, Ceara State, an endemic area of cutaneous leishmaniasis, and others from Curitiba, Parana State, a non endemic area. The results indicate the possibility of using this sorologic test to the epidemiologic research of the infection in the reservoir host; in this case, the dog.

Haroldo Sérgio da S. Bezerra

1996-04-01

149

Avaliação do teste de aglutinação direta na detecção da infecção por Leishmania (Viannia) braziliensis em possíveis reservatórios de leishmaniose tegumentar americana no estado do Ceará  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com o objetivo de avaliar a aplicabilidade do Teste de Aglutinação Direta (TAD) como método de detecção da infecção natural canina por Leishmania (Viannia) braziliensis, foi realizado um estudo envolvendo soros de cães residentes em uma área endêmica de leishmaniose tegumentar, Serra de Baturité, CE [...] e soros de cães provenientes da cidade de Curitiba, PR, área não endêmica de leishmaniose. Os resultados obtidos com o TAD neste trabalho indicam a possibilidade do uso deste teste sorológico para levantamentos epidemiólogicos da infecção em reservatórios; neste estudo, o cão doméstico. Abstract in english In order to evaluate the aplicability of the Direct Agglutination Test (DAT) as a method of detection of the natural canine infection for Leishmania (Viannia) braziliensis, it was realized a study involving the serum of naive dogs from Serra de Baturite, Ceara State, an endemic area of cutaneous lei [...] shmaniasis, and others from Curitiba, Parana State, a non endemic area. The results indicate the possibility of using this sorologic test to the epidemiologic research of the infection in the reservoir host; in this case, the dog.

Haroldo Sérgio da S., Bezerra; Joseval da Rocha, Viana; Maria Jania, Texeira; Cristina Sousa, Chaves; Daniela Bastos de, Araújo; José Hermênio C., Lima Filho.

1996-04-01

150

Leishmania (Viannia) braziliensis is the main species causing cutaneous leishmaniasis in the Federal District of Brazil  

Scientific Electronic Library Online (English)

Full Text Available The first autochthonous case of American cutaneous leishmaniasis was reported in the Federal District in 1980, and the species involved in this type of leishmaniasis was unknown. This study aimed to identify the species that causes the disease in the Federal District and to investigate its clinical [...] and epidemiological aspects. Between 2000 and 2007, 71 autochthonous cases of leishmaniasis were reported in the Federal District. Leishmania species were identified by means of direct immunofluorescence reactions using monoclonal antibodies and restriction fragment length polymorphism. The species of 40 (56.33%) out of 71 samples were identified. Thirty-six (90%) were identified as Leishmania (Viannia) braziliensis and four (10%) were identified as Leishmania (Leishmania) amazonensis. In this area, the disease had clinical and epidemiological characteristics similar to those found in other Brazilian regions.

GM, Santos; SA, Kückelhaus; AM, Roselino; WK, Chaer; RNR, Sampaio.

151

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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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 negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis e camundongos C57BL/6 (resistentes apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

Regina Coeli Cunha Dórea

2003-11-01

152

Polymerase chain reaction and real-time PCR for diagnosing of Leishmania infantum chagasi in dogs / Reação em Cadeia da Polimerase e PCR em tempo real para diagnóstico de Leishmania infantum chagasi em cães  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese A importância do cão como reservatório de L. infantum chagasi no meio urbano tem estimulado a realização de inúmeros trabalhos de avaliação de técnicas de diagnóstico, uma vez que este procedimento, quando realizado corretamente, torna-se um importante passo na prevenção da doença em humanos. Dentre [...] os métodos de diagnóstico, as técnicas moleculares têm adquirido destaque. Objetivou-se neste trabalho verificar o desempenho da Reação em Cadeia da Polimerase (PCR) e da PCR em tempo real (qPCR) para diagnóstico da Leishmaniose Visceral Canina (LVC) utilizando diferentes amostras biológicas. Para tanto foram utilizados 35 cães provenientes de uma área endêmica para LVC, onde foram utilizados para o diagnóstico molecular, aspirado de medula óssea, fragmentos de linfonodo e baço. Neste estudo a qPCR foi capaz de detectar um maior número de animais positivos quando comparada com a PCR. Já entre as diferentes amostras biológicas utilizadas não foi observada diferença significativa na detecção de DNA de L. infantumchagasi por meio da PCR e qPCR. Mesmo assim, considerando a facilidade de obtenção, o linfonodo pode ser considerada como a melhor amostra para diagnóstico molecular da infecção por L. infantum chagasi. Abstract in english The importance of dogs as a reservoir for Leishmania infantumchagasi in urban environments has stimulated numerous studies assessing diagnostic techniques. When performed properly, such procedures are an important step in preventing leishmaniasis in humans. Molecular methods have become prominent fo [...] r this purpose. The aim of the present study was to determine the performance of the polymerase chain reaction (PCR) and real-time PCR (qPCR) for diagnosing of canine visceral leishmaniasis (CVL) using different biological samples. For this, 35 dogs from an area endemic for CVL were used. Bone marrow aspirate and lymph node and spleen fragments from these dogs were used for the molecular diagnosis. In the present study, qPCR was able to detect a greater number of positive animals than seen with PCR. Among the different biological samples used, there was no significant difference in L. infantumchagasi DNA detection between PCR and qPCR. However, considering that lymph nodes are easy to acquire, these can be considered to be the best samples for making molecular diagnoses of L. infantum chagasi infection.

Rafael Antonio do Nascimento, Ramos; Carlos Alberto do Nascimento, Ramos; Márcia Mariza Gomes, Jusi; Flábio Ribeiro de, Araújo; Rosangela Zacarias, Machado; Maria Aparecida da Glória, Faustino; Leucio Câmara, Alves.

2012-09-01

153

Polymerase chain reaction and real-time PCR for diagnosing of Leishmania infantum chagasi in dogs Reação em Cadeia da Polimerase e PCR em tempo real para diagnóstico de Leishmania infantum chagasi em cães  

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Full Text Available The importance of dogs as a reservoir for Leishmania infantumchagasi in urban environments has stimulated numerous studies assessing diagnostic techniques. When performed properly, such procedures are an important step in preventing leishmaniasis in humans. Molecular methods have become prominent for this purpose. The aim of the present study was to determine the performance of the polymerase chain reaction (PCR and real-time PCR (qPCR for diagnosing of canine visceral leishmaniasis (CVL using different biological samples. For this, 35 dogs from an area endemic for CVL were used. Bone marrow aspirate and lymph node and spleen fragments from these dogs were used for the molecular diagnosis. In the present study, qPCR was able to detect a greater number of positive animals than seen with PCR. Among the different biological samples used, there was no significant difference in L. infantumchagasi DNA detection between PCR and qPCR. However, considering that lymph nodes are easy to acquire, these can be considered to be the best samples for making molecular diagnoses of L. infantum chagasi infection.A importância do cão como reservatório de L. infantum chagasi no meio urbano tem estimulado a realização de inúmeros trabalhos de avaliação de técnicas de diagnóstico, uma vez que este procedimento, quando realizado corretamente, torna-se um importante passo na prevenção da doença em humanos. Dentre os métodos de diagnóstico, as técnicas moleculares têm adquirido destaque. Objetivou-se neste trabalho verificar o desempenho da Reação em Cadeia da Polimerase (PCR e da PCR em tempo real (qPCR para diagnóstico da Leishmaniose Visceral Canina (LVC utilizando diferentes amostras biológicas. Para tanto foram utilizados 35 cães provenientes de uma área endêmica para LVC, onde foram utilizados para o diagnóstico molecular, aspirado de medula óssea, fragmentos de linfonodo e baço. Neste estudo a qPCR foi capaz de detectar um maior número de animais positivos quando comparada com a PCR. Já entre as diferentes amostras biológicas utilizadas não foi observada diferença significativa na detecção de DNA de L. infantumchagasi por meio da PCR e qPCR. Mesmo assim, considerando a facilidade de obtenção, o linfonodo pode ser considerada como a melhor amostra para diagnóstico molecular da infecção por L. infantum chagasi.

Rafael Antonio do Nascimento Ramos

2012-09-01

154

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)

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 ?g/ml (EC50), L.(V.) panamensis (0.78 |?g/ml) and L.(L.) chagasi (0.63 (?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 EC50 of 11|?g/ml. Irradiation of LAO with 60Co 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 EC50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

155

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis: 4. Classificação histopatológica / Histopathology of Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis: 4. A histopathological classification  

Scientific Electronic Library Online (English)

Full Text Available Os A A. analisaram as alterações histológicas encontradas em 162 casos de Leishmaniose Tegumentar da localidade de Três Braços, Estado da Bahia, dos quais 131 (80,9%) eram de portadores de lesões cutâneas e 31 (19,1%) de portadores de lesões mucosas. Analisaram, também, o comportamento clínico dos c [...] inco padrões histopatológicos, já antes descritos, em relação à terapêutica. O melhor prognóstico esteve sempre ligado ao padrão de Reação Exsudativa e Granulomatosa, ou seja, a uma fase na qual o organismo, tendo lançado mão de um mecanismo endógeno de lise parasitária, já circunscreveu a área de necrose por uma reação granulomatosa, e esta é agora apenas o elemento residual. A ação terapêutica nessa fase somente acelera a resolução natural do caso. O grupo seguinte é amplo, e compreende os casos em que a lesão pertence aos padrões de Reação Exsudativa Celular (formas cutâneas), Reação Exsudativa e Necrótica e Reação Exsudativa e Necrótico-Granulomatosa. Nesses casos, o mecanismo de auto-controle da lesão encontra-se ainda em curso, e a ação terapêutica encurta o período de evolução natural. Os f.asos do padrão de Reação Exsudativa e Tuberculóide tiveram um prognóstico variável. Houve boa resposta à terapêutica quando o granuloma tuberculóide característico desse padrão surgiu em pacientes jovens, com curto tempo de evolução da doença e intradermorreação não exacerbada. Nos demais casos tuberculóides —. principalmente em pacientes adultos, com longo tempo de evolução da doença e intradermorreação exacerbada —, a resposta foi menos satisfatória. Em último lugar, com prognóstico reservado, ficaram os casos da forma mucosa que apresentaram o padrão de Reação Exsudativa Celular, onde o infiltrado pode estar desempenhando papel de auto-agressão. O presente estudo evoluiu para a proposição de uma classificação da Leishmaniose Tegumentar, baseada nos padrões histopatológicos observados. Esta classificação, estritamente morfológica, deverá ser de fácil aplicação para o Patologista e, como apresenta também uma correspondência clínico-evolutiva poderá constituir auxílio valioso ao médico envolvido no diagnóstico e tratamento da Leishmaniose Tegumentar. Abstract in english The Authors have analysed the histopathological alterations observed in 162 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 131 (80,9%) had purely cutaneous lesions and 31 (19,1%) had only mucosal lesions. The clinical behavior of 5 histopathological forms was documented in rel [...] ation to treatment. The best prognosis was associated with the exudative granulomatous histopathology, a phase where the a host mechanism to use the parasite is evident leading to necrosis and granuloma formation as a residual sign. Therapy in this phase merely hastened the process. In a further large group the lesions were classified as exudative cellular reaction (cutaneous forms), an exudative necrotic reaction and an exudative necrotic gra- nulomatous reaction. In these cases the mechanisms of host defense are still being developed and the effect of therapy is to reduce the time to healing. Cutaneous cases with an exudative tuberculoid reaction had a worse prognosis, although there was a favourable response to treatment if the patient was young, the lesion was of short duration and the intradermal leishmanin test was not exaggerated Lastly are a group of mucosal cases with an exudative cellular reaction where this infiltrate may be a manifestation of auto agression. These cases, also classified as exudative tuberculoid, occur in adult patients with longstanding lesions and an exaggerated leishmanin skin test. They have a poor prognosis. This study develops suggestions for a classification based on the histopathological picture which could be valuable in predicting prognosis and influencing the choice of treatment. This classification is strictly morphological and is easy for the pathologist to apply. It appears to, correspond to

Albino Verçosa de, Magalhães; Mario A. P., Moraes; Alberto N., Raick; Alejandro, Llanos-Cuentas; Jackson M. L., Costa; César C., Cuba; Philip D., Marsden.

1986-12-01

156

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 3. Reação celular nos tecidos / Histopathology of mucocutaneous leishmaniasis caused by Leishmania braziliensis brasiliensis. 3. Cellular reaction.  

Scientific Electronic Library Online (English)

Full Text Available Os A.A. analisam as alterações histopatológicas observadas em 378 casos de Leishmaniose Tegumentar da localidade de Três Braços Estado da Bahia, dos quais 307 eram de portadores de lesões exclusivamente cutâneas, 54 de portadores de lesões exclusivamnte mucosas e 17 de portadores de lesões cutâneo-m [...] ucosas. A infiltração histiolinfoplasmocitária, na maioria dos casos, parece desempenhar o papel de resposta celular inespecífica à presença de um irritante tecidual, porém, nos casos de forma mucosa, não se pode afastar a possibilidade de que esse infiltrado esteja participando de uma reação de tipo autoagressivo. O plasmócito constitui um elemento quase constante nas lesões desenvolvidas, mas não tem sido observado nas lesões residuais, quer em via de cura ou já cicatrizadas; sua presença nestes casos denota, quase sempre, tendência à recidiva. Os mastdcitos foram observados em lesões tanto da forma cutânea como da forma mucosa, mas predominavam nas primeiras. Seu número foi significantemente maior no padrão de Reação Exsudativa e Neerótico Granulomatosa, onde os fenômenos necróticos são bem desenvolvidos. Os eosinófilos apresentaram associação significativa com os mastócitos, confirmando a existência de um eixo bidirecional entre estás duas células, o qual deve participar da modulação inflamatória, na Leishmaniose Tegumentar. Dois tipos de reação granulomatosa foram observados: um desorganizado, em relação, muitas vezes, com a necrose tissular, e outro organizado, mais raro, do tipo tuberculóide. O primeiro foi interpretado como de origem pós-necrótica, surgindo com a redução da carga parasitária, propiciada pelos fenômenos necróticos: eliminado o antígeno e mantidos os níveis de anticorpos, surgem as condições necessárias ao estabelecimento do granuloma, semelhante àquele observado nas lesões por imunocomplexo em excesso de anticorpos. O outro tipo de reação foi o granuloma de células epiteliódes, que surgiu em dois grupos de pacientes. Nos pacientes jovens, com doença de curto tempo de evolução e intradermorreação não exacerbada, este tipo de granuloma talvez seja a expressão da Hipersensibilidade Granulomatosa Específica, descrita por EPSTEIN (1977). No outro grupo de pacientes, havia em todos intradermorreação exacerbada. Nestes casos a hipersensibilidade granulomatosa, associando-se ã hipersensibilidade mediada por células — agora ampliada pelo seqüestro do antígeno —, reforçaria o processo granulomatoso, através da reverberação do estímulo antígênico; isso tornaria o tratamento mais difícil e pior o prognóstico para o caso. Abstract in english The Authors analyse the histopathological alterations observed in 378 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 307 (81,4%) were only cutaneous, 54 (14,2%) only mucosae and in 17 (4,4%) both integuments were involved simultaneously. A cellular infiltration of lymphocytes [...] and plasma cells was invariably present in all forms and during healing. In mucosal cases, this reaction may have an important role in maintaining an auto agression in the presence of few or no parasites. The plasma cell is a constant ele-ment in well developed lesions but not present in healing lesions. Its presence almost always denotes a tendancy to relapse. Mast cells were observed in both cutaneous and mucosal lesions but predominate in the former. Its number was significantly greater in those with an exudative and necrotic granulomatous reaction where necrotic phenomena are marked. Eosinophils were significantly associated with mast cells suggesting the existence of association between these cells in the modulation of the inflammatory response. Two types of granulomatous reaction were observed: a disorganized one, often related to tissue necrosis, and an organized, tuberculoid type granuloma. The first type is interpreted as of post necrotic origin resulting in a reduction in antigenic load with maintenance of antibody levels, creating the conditio

Albino Verçosa de, Magalhães; Mário A. P., Moraes; Alberto N., Raick; Alejandro, Llanos-Cuentas; Jackson M. L., Costa; César C., Cuba; Philip D., Marsden.

1986-10-01

157

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis. 3. Reação celular nos tecidos Histopathology of mucocutaneous leishmaniasis caused by Leishmania braziliensis brasiliensis. 3. Cellular reaction.  

Directory of Open Access Journals (Sweden)

Full Text Available Os A.A. analisam as alterações histopatológicas observadas em 378 casos de Leishmaniose Tegumentar da localidade de Três Braços Estado da Bahia, dos quais 307 eram de portadores de lesões exclusivamente cutâneas, 54 de portadores de lesões exclusivamnte mucosas e 17 de portadores de lesões cutâneo-mucosas. A infiltração histiolinfoplasmocitária, na maioria dos casos, parece desempenhar o papel de resposta celular inespecífica à presença de um irritante tecidual, porém, nos casos de forma mucosa, não se pode afastar a possibilidade de que esse infiltrado esteja participando de uma reação de tipo autoagressivo. O plasmócito constitui um elemento quase constante nas lesões desenvolvidas, mas não tem sido observado nas lesões residuais, quer em via de cura ou já cicatrizadas; sua presença nestes casos denota, quase sempre, tendência à recidiva. Os mastdcitos foram observados em lesões tanto da forma cutânea como da forma mucosa, mas predominavam nas primeiras. Seu número foi significantemente maior no padrão de Reação Exsudativa e Neerótico Granulomatosa, onde os fenômenos necróticos são bem desenvolvidos. Os eosinófilos apresentaram associação significativa com os mastócitos, confirmando a existência de um eixo bidirecional entre estás duas células, o qual deve participar da modulação inflamatória, na Leishmaniose Tegumentar. Dois tipos de reação granulomatosa foram observados: um desorganizado, em relação, muitas vezes, com a necrose tissular, e outro organizado, mais raro, do tipo tuberculóide. O primeiro foi interpretado como de origem pós-necrótica, surgindo com a redução da carga parasitária, propiciada pelos fenômenos necróticos: eliminado o antígeno e mantidos os níveis de anticorpos, surgem as condições necessárias ao estabelecimento do granuloma, semelhante àquele observado nas lesões por imunocomplexo em excesso de anticorpos. O outro tipo de reação foi o granuloma de células epiteliódes, que surgiu em dois grupos de pacientes. Nos pacientes jovens, com doença de curto tempo de evolução e intradermorreação não exacerbada, este tipo de granuloma talvez seja a expressão da Hipersensibilidade Granulomatosa Específica, descrita por EPSTEIN (1977. No outro grupo de pacientes, havia em todos intradermorreação exacerbada. Nestes casos a hipersensibilidade granulomatosa, associando-se ã hipersensibilidade mediada por células — agora ampliada pelo seqüestro do antígeno —, reforçaria o processo granulomatoso, através da reverberação do estímulo antígênico; isso tornaria o tratamento mais difícil e pior o prognóstico para o caso.The Authors analyse the histopathological alterations observed in 378 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 307 (81,4% were only cutaneous, 54 (14,2% only mucosae and in 17 (4,4% both integuments were involved simultaneously. A cellular infiltration of lymphocytes and plasma cells was invariably present in all forms and during healing. In mucosal cases, this reaction may have an important role in maintaining an auto agression in the presence of few or no parasites. The plasma cell is a constant ele-ment in well developed lesions but not present in healing lesions. Its presence almost always denotes a tendancy to relapse. Mast cells were observed in both cutaneous and mucosal lesions but predominate in the former. Its number was significantly greater in those with an exudative and necrotic granulomatous reaction where necrotic phenomena are marked. Eosinophils were significantly associated with mast cells suggesting the existence of association between these cells in the modulation of the inflammatory response. Two types of granulomatous reaction were observed: a disorganized one, often related to tissue necrosis, and an organized, tuberculoid type granuloma. The first type is interpreted as of post necrotic origin resulting in a reduction in antigenic load with maintenance of antibody levels, creating the conditions to establish a granuloma similar to

Albino Verçosa de Magalhães

1986-10-01

158

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis: 4. Classificação histopatológica Histopathology of Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis: 4. A histopathological classification  

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Full Text Available Os A A. analisaram as alterações histológicas encontradas em 162 casos de Leishmaniose Tegumentar da localidade de Três Braços, Estado da Bahia, dos quais 131 (80,9% eram de portadores de lesões cutâneas e 31 (19,1% de portadores de lesões mucosas. Analisaram, também, o comportamento clínico dos cinco padrões histopatológicos, já antes descritos, em relação à terapêutica. O melhor prognóstico esteve sempre ligado ao padrão de Reação Exsudativa e Granulomatosa, ou seja, a uma fase na qual o organismo, tendo lançado mão de um mecanismo endógeno de lise parasitária, já circunscreveu a área de necrose por uma reação granulomatosa, e esta é agora apenas o elemento residual. A ação terapêutica nessa fase somente acelera a resolução natural do caso. O grupo seguinte é amplo, e compreende os casos em que a lesão pertence aos padrões de Reação Exsudativa Celular (formas cutâneas, Reação Exsudativa e Necrótica e Reação Exsudativa e Necrótico-Granulomatosa. Nesses casos, o mecanismo de auto-controle da lesão encontra-se ainda em curso, e a ação terapêutica encurta o período de evolução natural. Os f.asos do padrão de Reação Exsudativa e Tuberculóide tiveram um prognóstico variável. Houve boa resposta à terapêutica quando o granuloma tuberculóide característico desse padrão surgiu em pacientes jovens, com curto tempo de evolução da doença e intradermorreação não exacerbada. Nos demais casos tuberculóides —. principalmente em pacientes adultos, com longo tempo de evolução da doença e intradermorreação exacerbada —, a resposta foi menos satisfatória. Em último lugar, com prognóstico reservado, ficaram os casos da forma mucosa que apresentaram o padrão de Reação Exsudativa Celular, onde o infiltrado pode estar desempenhando papel de auto-agressão. O presente estudo evoluiu para a proposição de uma classificação da Leishmaniose Tegumentar, baseada nos padrões histopatológicos observados. Esta classificação, estritamente morfológica, deverá ser de fácil aplicação para o Patologista e, como apresenta também uma correspondência clínico-evolutiva poderá constituir auxílio valioso ao médico envolvido no diagnóstico e tratamento da Leishmaniose Tegumentar.The Authors have analysed the histopathological alterations observed in 162 cases of Mucocutaneous Leishmaniasis from Três Braços, Bahia, of whom 131 (80,9% had purely cutaneous lesions and 31 (19,1% had only mucosal lesions. The clinical behavior of 5 histopathological forms was documented in relation to treatment. The best prognosis was associated with the exudative granulomatous histopathology, a phase where the a host mechanism to use the parasite is evident leading to necrosis and granuloma formation as a residual sign. Therapy in this phase merely hastened the process. In a further large group the lesions were classified as exudative cellular reaction (cutaneous forms, an exudative necrotic reaction and an exudative necrotic gra- nulomatous reaction. In these cases the mechanisms of host defense are still being developed and the effect of therapy is to reduce the time to healing. Cutaneous cases with an exudative tuberculoid reaction had a worse prognosis, although there was a favourable response to treatment if the patient was young, the lesion was of short duration and the intradermal leishmanin test was not exaggerated Lastly are a group of mucosal cases with an exudative cellular reaction where this infiltrate may be a manifestation of auto agression. These cases, also classified as exudative tuberculoid, occur in adult patients with longstanding lesions and an exaggerated leishmanin skin test. They have a poor prognosis. This study develops suggestions for a classification based on the histopathological picture which could be valuable in predicting prognosis and influencing the choice of treatment. This classification is strictly morphological and is easy for the pathologist to apply. It appears to, correspond to the clinical course of the illness and c

Albino Verçosa de Magalhães

1986-12-01

159

Efficacy of the photodynamic antimicrobial therapy (PACT) with the use of methylene blue associated with the ?660nm laser in Leishmania (Leishmania) amazonesis: in vitro study  

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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

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

160

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  

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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)

Cardoso, Andre Gustavo Tempone

1999-07-01

161

Actividad in vitro de la mezcla de alcaloides de Ervatamia coronaria (Jacq) Staff. Apocynaceae sobre amastigotes de Leishmania braziliensis / In vitro activity of the alkaloids mixture of Ervatamia coronaria (Jacq) Staff. Apocynaceae on Leishmania braziliensis amastigotes / Atividade in vitro da mistura de alcalóides de Ervatamia coronaria (Jacq) Staff. Apocynaceae sobre amastigotas de Leishmania braziliensis  

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Full Text Available SciELO Brazil | Language: Spanish Abstract in portuguese 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. Abstract in spanish [...] Abstract in english Leishmaniasis, caused by Leishmania sp., is one of the mean reason of considerable mortality and morbidity throughout the world, especially in the tropics. Cutaneous and mucocutaneous manifestations are caused by Leishmania braziliensis, and the cutaneous form is the most common one in Colombia. In [...] the search for antileishmanial compounds from natural sources, we studied the alkaloids mixture from Ervatamia coronaria against L. braziliensis at six different concentrations (1.0, 10, 20, 25, 50 and 100 µg/mL). Macrophages J774 infected with L. braziliensis were treated with alkaloids one hour, and once a day for three days, after parasitic infection and preserving the same culture medium. Cytotoxicity with trypan blue was undertaken in macrophages J774 by using the same concentrations. Three different cultures samples were carried out. As a control we used medium alone. The alkaloids mix showed a dose/dependent activity on amastigote, but by increasing concentrations from 50 to 100 µg/mL for three days, we saw a high index of infection, probably caused by cellular death. We did not see any toxic effect on macrophages J774 at 100 µg/mL, LD50/24h= 233.52 µg/mL. These results revealed a novel pharmacological activity of alkaloids from E. coronaria against amastigotes of L. braziliensis IC50 = 2.6 and 12.4 µg/mL without toxicity on host cells.

Amanda, Moreno Rodríguez; Jorge, Robles Camargo; Felio J., Bello García.

2008-09-01

162

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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Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo. Abstract in english 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 Leishm [...] ania 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.

Regina Coeli Cunha, Dórea; Carlos Gomes, Barboza-Filho; Dayson Friaça, Moreira; Mirian, Guirro; Ágtha de Alencar Muniz, Chaves; Ricardo José, Dunder; Elaine Amorim, Soares; Vitório, Santos-Júnior; Wilma, Spinosa.

2003-11-01

163

Combining diagnostic procedures for the management of leishmaniasis in areas with high prevalence of Leishmania guyanensis Procedimentos diagnósticos combinados no manejo da leishmaniose em áreas com alta prevalência de Leishmania guyanensis  

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BACKGROUND: The Amazon region corresponds to approximately 40% of the cases of leishmaniasis in Brazil. We report a prospective study with 180 patients conducted in a health care unit that diagnoses 10% of the cases of leishmaniasis in the Brazilian Amazon. The study addresses how a combination of procedures improves diagnosis in areas with high prevalence of Leishmania guyanensis. OBJECTIVES: to evaluate diagnostic methods in areas with high prevalence of Leishmania guyanensis. METHODS: All ...

Ednelza de Almeida Benicio; Ellen Pricilla Nunes Gadelha; Anette Talhari; Roberto Moreira da Silva Jr; Luis Carlos Ferreira; Mayara Cristina Cordeiro dos Santos; Marcelo Távora Mira; Cintia Mara Costa de Oliveira; Carolina Talhari; Sinésio Talhari; Paulo Roberto Machado; Albert Schriefer

2011-01-01

164

Terpenes Increase the Lipid Dynamics in the Leishmania Plasma Membrane at Concentrations Similar to Their IC50 Values  

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Although many terpenes have shown antitumor, antibacterial, antifungal, and antiparasitic activity, the mechanism of action is not well established. Electron paramagnetic resonance (EPR) spectroscopy of the spin-labeled 5-doxyl stearic acid revealed remarkable fluidity increases in the plasma membrane of terpene-treated Leishmania amazonensis promastigotes. For an antiproliferative activity assay using 5×106 parasites/mL, the sesquiterpene nerolidol and the monoterpenes (+)-limonene, ?-terp...

Camargos, Heverton Silva; Moreira, Rodrigo Alves; Mendanha, Sebastia?o Antonio; Fernandes, Kelly Souza; Dorta, Miriam Leandro; Alonso, Antonio

2014-01-01

165

In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis  

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PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb)...

Chamakh-ayari, Rym; Bras-gonc?alves, Rachel; Bahi-jaber, Narges; Petitdidier, Elodie; Markikou-ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-agapito, Francesca; Privat, Angela; Cruz, Maria

2014-01-01

166

Studies on cocktails of 31-kDa, 36-kDa and 51-kDa antigens of Leishmania donovani along with saponin against murine visceral leishmaniasis.  

Science.gov (United States)

A substantial number of antigens of Leishmania donovani have been described in the past. However, identifying candidate antigens is not enough. Appropriate antigen delivery to induce the right type of immune response against leishmaniasis (i.e. induction of a strong antigen-specific Th1 type of immune response) is another crucial component of an effective vaccine. Therefore, 'cocktail' vaccines are proposed based on the assumption that such cocktails will show enhanced efficacy. Studies have been carried out on LD31 and LD51 polypeptides from L. donovani promastigotes, which have proven to be potential vaccine candidates. This study was designed to check the protective efficacy of various cocktails of low molecular weight antigens alone and along with saponin as adjuvant. Mice were sacrificed on different post-challenge days for evaluation of parasite load and other immunological parameters. Protective efficacy of different vaccine formulations was revealed by significant decline in parasite burden and increased DTH Delayed Type Hypersenstivity responses. The antibody response was of IgG type with elevated IgG2a and decreased production of IgG1, whereas cytokine levels pointed towards the generation of protective Th1 type of immune response. Among all vaccine formulations, cocktail of 31+51+saponin was found to be highly immunogenic and imparted maximum protection. PMID:25615543

Kaur, H; Thakur, A; Kaur, S

2015-04-01

167

Leishmania braziliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of American Cutaneous Leishmaniasis / Leishmania braziliensis: isolamento de antígeno contendo carboidrato e a possibilidade de sua aplicação no imunodiagnóstico da Leishmaniose Tegumentar Americana  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese A Leishmania braziliensis é um dos agentes causadores da Leishmaniose Tegumentar Americana (LTA). A cepa 034-JCG, isolada de paciente da região norte do estado do Paraná, Brasil, foi cultivada em meio Blood Agar Base, liofilizada e submetida a extração com fenol-água e o extrato obtido foi tratado c [...] om RNase I. O antígeno contendo carboidrato (Ag-CHO) mostrou-se imunogênico para coelhos e apresentou pelo menos uma fração com poucas cargas negativas em pH 8,2. Este antígeno apresenta reação cruzada com extrato fenólico do meio de cultura usado para o cultivo de promastigotas e com antígenos de superfície de promastigotas. É composto por 24,3% de açúcares totais, dos quais 11,2% de galactose, 7,5% de manose e 5,6% de ribose. As proteínas foram estimadas em 5,4% e fosfato em 18,5%. A atividade antigênica foi mantida após: congelamentos e descongelamentos repetidos; liofilização; aquecimento a 100ºC durante 30 minutos; tratamento com RNase, ácido tricloroacético e periodato de sódio. As linhas obtidas nas reações de precipitação coram-se pelo Ácido Periódico de Schiff. A utilização do Ag-CHO na reação de contraimunoeletroforese para o imunodiagnóstico de LTA mostrou 60% de sensibilidade, e nenhuma reação cruzada com os 5 soros de pacientes com Doença de Chagas testados. O uso deste antígeno com técnicas mais sensíveis, e com um maior número de amostras poderá melhorar estes resultados. Abstract in english Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL). The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treate [...] d with RNase I. The carbohydrate containing-antigen (Ag-CHO) was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100ºC for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.

T. G. V., Silveira; C, Kemmelmeier.

1995-06-01

168

Leishmania braziliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of American Cutaneous Leishmaniasis Leishmania braziliensis: isolamento de antígeno contendo carboidrato e a possibilidade de sua aplicação no imunodiagnóstico da Leishmaniose Tegumentar Americana  

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Full Text Available Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL. The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treated with RNase I. The carbohydrate containing-antigen (Ag-CHO was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100ºC for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.A Leishmania braziliensis é um dos agentes causadores da Leishmaniose Tegumentar Americana (LTA. A cepa 034-JCG, isolada de paciente da região norte do estado do Paraná, Brasil, foi cultivada em meio Blood Agar Base, liofilizada e submetida a extração com fenol-água e o extrato obtido foi tratado com RNase I. O antígeno contendo carboidrato (Ag-CHO mostrou-se imunogênico para coelhos e apresentou pelo menos uma fração com poucas cargas negativas em pH 8,2. Este antígeno apresenta reação cruzada com extrato fenólico do meio de cultura usado para o cultivo de promastigotas e com antígenos de superfície de promastigotas. É composto por 24,3% de açúcares totais, dos quais 11,2% de galactose, 7,5% de manose e 5,6% de ribose. As proteínas foram estimadas em 5,4% e fosfato em 18,5%. A atividade antigênica foi mantida após: congelamentos e descongelamentos repetidos; liofilização; aquecimento a 100ºC durante 30 minutos; tratamento com RNase, ácido tricloroacético e periodato de sódio. As linhas obtidas nas reações de precipitação coram-se pelo Ácido Periódico de Schiff. A utilização do Ag-CHO na reação de contraimunoeletroforese para o imunodiagnóstico de LTA mostrou 60% de sensibilidade, e nenhuma reação cruzada com os 5 soros de pacientes com Doença de Chagas testados. O uso deste antígeno com técnicas mais sensíveis, e com um maior número de amostras poderá melhorar estes resultados.

T. G. V. Silveira

1995-06-01

169

Activity of Brazilian and Bulgarian propolis against different species of Leishmania  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species - Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L. major from the Old World - associated to different clinical forms of leishmaniasis. The composition of the extra [...] cts has been previously characterized by high temperature high resolution gas chromatography coupled to mass spectrometry. Considering the chemical differences among the extracts and the behavior of the parasites, it was observed significant differences in the leishmanicidal activities with IC50/1 day values in the range of 2.8 to 229.3 µg/ml . An overall analysis showed that for all the species evaluated, Bulgarian extracts were more active than the ethanol Brazilian extract. As the assayed propolis extracts have their chemical composition determined it merits further investigation the effect of individual components or their combinations on each Leishmania species.

Gérzia Maria de Carvalho, Machado; Leonor Laura, Leon; Solange Lisboa de, Castro.

2007-02-01

170

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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Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 e nenhum sinal clínico, parasito ou anticorpo foi detectado em novos exames realizados ao longo de seis meses. Os resultados desse trabalho sugerem portanto, a presença de uma co-infecção entre os três parasitos citados nas áreas endêmicas e não a reação cruzada entre eles, nos testes sorológicos de RIFI e ELISA descritos. Abstract in english 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.

Trícia Maria F. de Sousa, Oliveira; Patrícia I., Furuta; Débora de, Carvalho; Rosangela Z., Machado.

2008-03-01

171

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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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 e nenhum sinal clínico, parasito ou anticorpo foi detectado em novos exames realizados ao longo de seis meses. Os resultados desse trabalho sugerem portanto, a presença de uma co-infecção entre os três parasitos citados nas áreas endêmicas e não a reação cruzada entre eles, nos testes sorológicos de RIFI e ELISA descritos.

Trícia Maria F. de Sousa Oliveira

2008-03-01

172

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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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.

L. Ryan

1987-09-01

173

Purification and biochemical characterization of three myotoxins from Bothrops mattogrossensis snake venom with toxicity against Leishmania and tumor cells.  

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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. PMID:24724078

de Moura, Andréa A; Kayano, Anderson M; Oliveira, George A; Setúbal, Sulamita S; Ribeiro, João G; Barros, Neuza B; Nicolete, Roberto; Moura, Laura A; Fuly, Andre L; Nomizo, Auro; da Silva, Saulo L; Fernandes, Carla F C; Zuliani, Juliana P; Stábeli, Rodrigo G; Soares, Andreimar M; Calderon, Leonardo A

2014-01-01

174

Evaluation of Leishmania (Leishmania chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis Avaliação de amostras de Leishmania (Leishmania chagasi isoladas de cães oriundos de duas áreas endêmicas de leishmaniose visceral no Brasil através da eletroforese de isoenzimas  

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Full Text Available INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57 and Belo Horizonte (n = 96, where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP. RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75. Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme.INTRODUÇÃO: Cães domésticos são considerados os reservatórios mais importantes no ciclo peridoméstico de transmissão de Leishmania (Leishmania chagasi. No entanto, a variabilidade genética de sub-populações que circulam neste hospedeiro é ainda pouco explorada no Brasil, sendo tal conhecimento de grande importância no contexto clínico-epidemiológico. MÉTODOS: O objetivo deste estudo foi avaliar e comparar a variabilidade fenotípica de 153 amostras de L. chagasi isoladas de cães oriundos dos municípios do Rio de Janeiro (n = 57 e Belo Horizonte (n = 96, onde a doença é endêmica. Foram selecionadas somente amostras isoladas de pele íntegra e analisadas por eletroforese de isoenzimas (MLEE empregando nove sistemas enzimáticos (6PG, GPI, NH1 e NH2, G6P, PGM, MDH, ME, IDHNADP. RESULTADOS: Todas as amostras analisadas apresentaram perfil eletroforético idêntico entre si e com a amostra de L. chagasi utilizada como referência neste estudo (MHOM/BR/74/PP75. A análise fenética demonstrou índice de similaridade igual a um para todas as amostras, revelando um compartilhamento de 100% dos caracteres avaliados. CONCLUSÕES: A partir desses resultados, podemos inferir que as populações de L. chagasi que estão circulando nos cães do Rio de Janeiro e Belo Horizonte podem ser agrupadas em um único zimodema.

Carlos Eduardo Ribeiro Coutinho

2011-10-01

175

Clavulina amazonensis, an Amazonian fungus discovered in the Atlantic Forest / Clavulina amazonensis, un hongo amazónico descubierto en la Mata Atlántica  

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Full Text Available SciELO Argentina | Language: English Abstract in spanish Se reporta Clavulina amazonensis por primera vez para la Selva Atlántica del Nordeste de Brasil con base en material de herbario. La especie se caracteriza por basidiosporas subglobosas pequeñas, basidios con dos a tries esterigmas cornudos y contexto con hifas marrón anaranjadas. Se presenta descri [...] pción, ilustraciones y una discusión sobre su distribución. Abstract in english Clavulina amazonensis is reported for the first time in the Atlantic Forest of Northeastern Brazil from herbarium material. C. amazonensis is characterized by branched basidiomes with, hymenium, small subglobose basidiospores, frequency of three sterigmata per basidia and context bearing orange-brow [...] n hyphae. Description, drawings, and discussion on its biogeography are provided here.

Felipe, Wartchow.

2012-06-01

176

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity  

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Full Text Available Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by [...] recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 µM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 µM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (~40%) in the presence of SNAP (30-150 µM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.

P.R.T., Romão; J., Tovar; S.G., Fonseca; R.H., Moraes; A.K., Cruz; J.S., Hothersall; A.A., Noronha-Dutra; S.H., Ferreira; F.Q., Cunha.

2006-03-01

177

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity  

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Full Text Available Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP, a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7 parasites, regardless Leishmania species. The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7 parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 µM. The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 µM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (~40% in the presence of SNAP (30-150 µM. In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.

P.R.T. Romão

2006-03-01

178

A novel A2 allele found in Leishmania (Leishmania infantum chagasi Novo alelo do gene A2 descrito em Leishmania (Leishmania infantum chagasi  

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Full Text Available Visceral leishmaniasis (VL is a widely spread zoonotic disease. In Brazil the disease is caused by Leishmania (Leishmania infantum chagasi. Peridomestic sandflies acquire the etiological agent by feeding on blood of infected reservoir animals, such as dogs or wildlife. The disease is endemic in Brazil and epidemic foci have been reported in densely populated cities all over the country. Many clinical features of Leishmania infection are related to the host-parasite relationship, and many candidate virulence factors in parasites that cause VL have been studied such as A2 genes. The A2 gene was first isolated in 1994 and then in 2005 three new alleles were described in Leishmania (Leishmania infantum. In the present study we amplified by polymerase chain reaction (PCR and sequenced the A2 gene from the genome of a clonal population of L. (L. infantum chagasi VL parasites. The L. (L. infantum chagasi A2 gene was amplified, cloned, and sequenced in. The amplified fragment showed approximately 90% similarity with another A2 allele amplified in Leishmania (Leishmania donovani and in L.(L. infantum described in literature. However, nucleotide translation shows differences in protein amino acid sequence, which may be essential to determine the variability of A2 genes in the species of the L. (L. donovani complex and represents an additional tool to help understanding the role this gene family may have in establishing virulence and immunity in visceral leishmaniasis. This knowledge is important for the development of more accurate diagnostic tests and effective tools for disease control.A leishmaniose visceral (LV é uma zoonose amplamente disseminada, causada no Brasil pela Leishmania (Leishmania infantum chagasi. Flebotomíneos vetores adquirem o agente etiológico, alimentando-se do sangue de animais contaminados, como cachorros ou animais selvagens. A doença é endêmica no Brasil, e focos de epidemia são relatados em cidades densamente povoadas por todo o país. Muitas manifestações clínicas relacionadas à infecção por Leishmania estão ligadas à relação parasito-hospedeiro, e vários possíveis fatores de virulência dos parasitas, que causam a LV, são alvos de estudo, tais como os genes A2. O gene A2 foi isolado pela primeira vez em 1994 e, em seguida, em 2005, três novos alelos foram descritos em Leishmania (Leishmania infantum. No presente estudo, um fragmento do gene A2 de uma população clonal de L.(L. infantum chagasi foi amplificado por PCR e sua sequência de nucleotídeos determinada. O fragmento mostrou 90% de similaridade com alelos do gene A2 de Leishmania (Leishmania donovani e de L. (L. infantum, descritos na literatura. Entretanto, a tradução da sequência de nucleotídeos mostra diferenças na sequência de aminoácidos da proteína, que podem ser essenciais em determinar a variabilidade do gene A2 em espécies do complexo L. (L. donovani e representa uma ferramenta adicional na compreenssão do papel dessa família de genes na virulência e imunidade da leishmaniose visceral. O conhecimento dessa variação é importante para o desenvolvimento de testes diagnósticos mais precisos e ferramentas mais eficazes no controle da doença.

Trícia Maria Ferreira de Sousa Oliveira

2011-03-01

179

Experimental infection of canine peritoneal macrophages with visceral and dermotropic Leishmania strains  

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Full Text Available A study was carried out using macrophages cultured from the peritoneal exudate of dogs infected in vitro with three species of Leishmania: L. (L. chagasi, L. (Viannia braziliensis and L. (L. amazonensis with the aim of investigating the growth kinetics and infectivity of these species in the host cell. Results were expressed as the percentage of macrophages infected measured at 24 hr intervals over six days in RPMI - 1640 culture medium at a temperature of 34-35oC. The findings open the possibility of using canine peritoneal cells as a model for the screenning of leishmanicide drugs and to study the pathogenesis of these species.

Madeira MF

1999-01-01

180

Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium / Isolamento e crescimento de Leishmania (Leishmania) infantum chagasi em meio de crescimento condicionado de cultura celular  

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Full Text Available Leishmânias podem ser produzidas em meio de crescimento condicionado, após o cultivo de células McCoy (MCC). Promastigotas crescidas em meio semi-sólido NNN foram inoculadas em MCC, inicialmente, 100 parasitos por poço com 2,5 mL de McCoyMCC, em placas com 24 poços, sua multiplicação foi observada p [...] or uma cinética de 120 horas. Após este tempo, o meio estava saturado de promastigotas. A reprodução das leishmânias foi acompanhada a cada 24 horas, com contagem do número de parasitos por campo fotomicrografado. Como vantagem da técnica do crescimento da leishmânia em MCC tem-se o seu baixo custo, com pequena quantidade de parasitos pode-se obter o aumento da densidade de promastigotas em tempo reduzido. Com o emprego dessa técnica pode-se estudar o comportamento e a multiplicação das leishmânias nos vertebrados e invertebrados, assim como, obter antígenos, tanto brutos (leishmânia) como solúveis, produzidos pelos parasitos, que poderão ser úteis para se desenvolver kits de diagnósticos. Abstract in english Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After [...] day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.

Yeda L., Nogueira; Eunice A.B., Galati.

2006-06-01

181

Reproduction of Leishmania (Leishmania infantum chagasi in conditioned cell culture growth medium Isolamento e crescimento de Leishmania (Leishmania infantum chagasi em meio de crescimento condicionado de cultura celular  

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Full Text Available Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM. Leishmania (Leishmania infantum chagasi (100 parasites grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells and its multiplication was observed for five days (120 hours. After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes. The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.Leishmânias podem ser produzidas em meio de crescimento condicionado, após o cultivo de células McCoy (MCC. Promastigotas crescidas em meio semi-sólido NNN foram inoculadas em MCC, inicialmente, 100 parasitos por poço com 2,5 mL de McCoyMCC, em placas com 24 poços, sua multiplicação foi observada por uma cinética de 120 horas. Após este tempo, o meio estava saturado de promastigotas. A reprodução das leishmânias foi acompanhada a cada 24 horas, com contagem do número de parasitos por campo fotomicrografado. Como vantagem da técnica do crescimento da leishmânia em MCC tem-se o seu baixo custo, com pequena quantidade de parasitos pode-se obter o aumento da densidade de promastigotas em tempo reduzido. Com o emprego dessa técnica pode-se estudar o comportamento e a multiplicação das leishmânias nos vertebrados e invertebrados, assim como, obter antígenos, tanto brutos (leishmânia como solúveis, produzidos pelos parasitos, que poderão ser úteis para se desenvolver kits de diagnósticos.

Yeda L. Nogueira

2006-06-01

182

In vitro cytokines profile and ultrastructural changes of microglia and macrophages following interaction with Leishmania.  

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In the present study, we assessed morphological changes and cytokine production after in vitro interaction with causative agents of American cutaneous leishmaniasis and compared the microglia and macrophage immune responses. Cultures of microglia and macrophages infected with stationary-phase promastigotes of Leishmania (Viannia) shawi, Leishmania (Viannia) braziliensis or Leishmania (Leishmania) amazonensis were evaluated 24, 48 and 72 h after interaction. Macrophages only presented the classical phagocytic process while microglia also displayed large cytoplasmic projections similar to the ruffles described in macropinocytosis. In the macrophage cultures, the percentage of infected cells increased over time, in a fashion that was dependent on the parasite species. In contrast, in microglial cells as the culture time progressed, there was a significant reduction in the percentage of infected cells independent of parasite species. Measurements of cytokines in macrophage cultures 48 h after interactions revealed distinct expression patterns for different parasites, whereas in microglial cultures they were similar for all Leishmania tested species. Taken together, our results suggest that microglia may have a higher phagocytic ability and cytotoxic potential than macrophages for all investigated species. The robust response of microglia against all parasite species may suggest microglia have an important role in the defence against cerebral leishmaniasis. PMID:24717447

Ramos, Patricia Karla Santos; Brito, Maysa de Vasconcelos; Silveira, Fernando Tobias; Salgado, Cláudio Guedes; De Souza, Wanderley; Picanço-Diniz, Cristovam Wanderley; Picanço-Diniz, José Antonio Junior

2014-07-01

183

Genetic variation in populations of Leishmania species in Brazil.  

Science.gov (United States)

The population structure of strains of Leishmania (Viannia) braziliensis sensu lato from Pará State and Paraná State in Brazil, of L. (V.) shawi and L. (Leishmania) amazonensis from Pará State, and the relationships of type strains of the subgenera L. (Viannia) and L. (Leishmania) were examined by the random-amplified polymorphic deoxyribonucleic acid (RAPD) technique. Four different primers (M13-40, QG1, L15996 and delta gt11R) were used. The bands were analysed using the neighbor-joining (NJ) and unweighted pair-group method with arithmetic averages (UPGMA) algorithms of the MEGA package. The topology of the NJ and UPGMA trees was very similar but they were not always identical. Both trees differentiated the standard strains of the different species. Strains from the same location were grouped together only in the UPGMA phenogram of the M13-40 primer. L. (V.) braziliensis isolates from Paraná State were genetically closer to those from Paragominas, Pará State than to those from the Amazonian regions of Carajás in Pará State and Peru. The relationship was not dependent on geographical distance. It is postulated that the groups arose from different origins, in which the Amazonian stocks were related to Psychodopygus sand flies while the Paraná strains originated from a gene pool transmitted by Lutzomyia sand flies such as Lutzomyia (Nyssomyia) whitmani. Transmission by Ps. complexus in Paragominas is considered to be a secondary adaptation from the Lutzomyia leishmanial gene pool. Although the vectors of L. (V.) braziliensis are poorly known in the Amazon region, there is strong evidence that the major vectors are all Psychodopygus spp. There was a high degree of genetic variability amongst the L. (V.) shawi strains and there was no clear grouping according to the strains' origins. The genetic variability amongst L. (L.) amazonensis strains from the same locations was much lower but they formed 2 groups which coincided with their origin. Our results support the clonal population structure of Leishmania isolates and suggest that their distribution is related to the origin of the gene pool as well as to present vector and reservoir movements. PMID:12055823

Ishikawa, E A Y; Silveira, F T; Magalhães, A L P; Guerra júnior, R B; Melo, M N; Gomes, R; Silveira, T G V; Shaw, J J

2002-04-01

184

The role of surface glycoconjugates in Leishmania midgut attachment examined by competitive binding assays and experimental development in sand flies.  

Science.gov (United States)

Binding of promastigotes to the sand fly midgut epithelium is regarded as an essential part of the Leishmania life cycle in the vector. Among Leishmania surface molecules putatively involved in attachment to the sand fly midgut, two GPI-anchored molecules are the most prominent: lipophosphoglycan (LPG) and promastigote surface protease gp63. In this work, we examined midgut attachment of Leishmania lines mutated in GPI-anchored molecules and compared results from 2 different techniques: in vivo development in sand flies and in vitro competitive binding assays using fluorescently labelled parasites. In combination with previous studies, our data provide additional support for (1) an LPG-independent parasite-binding mechanism of Leishmania major within the midgut of the permissive vector Phlebotomus perniciosus, and provide strong support for (2) the crucial role of L. major LPG in specific vector Phlebotomus papatasi, and (3) a role for Leishmania amazonensis gp63 in Lutzomyia longipalpis midgut binding. Moreover, our results suggest a critical role for GPI-anchored proteins and gp63 in Leishmania mexicana attachment to L. longipalpis midguts, as the wild type (WT) line accounted for over 99% of bound parasites. PMID:23611086

Jecna, Lucie; Dostalova, Anna; Wilson, Ray; Seblova, Veronika; Chang, Kwang-Poo; Bates, Paul A; Volf, Petr

2013-07-01

185

Molecular differentiation of Leishmania protozoarium using CdS quantum dots as biolabels  

Science.gov (United States)

In this work we applied core-shell CdS/Cd(OH)2 quantum dots (QDs) as fluorescent labels in the Leishmania amazonensis protozoarium. The nanocrystals (8-9 nm) are obtained via colloidal synthesis in aqueous medium, with final pH=7 using sodium polyphosphate as the stabilizing agent. The surface of the particles is passivated with a cadmium hydroxide shell and the particle surface is functionalized with glutaraldehyde. The functionalized and non-functionalized particles were conjugated to Leishmania organisms in the promastigote form. The marked live organisms were visualized using confocal microscopy. The systems exhibit a differentiation of the emission color for the functionalized and non-functionalized particles suggesting different chemical interactions with the promastigote moieties. Two photon emision spectra (? exc=795nm) were obtained for the promastigotes labeled with the functionalized QDs showing a significant spectral change compared to the original QDs suspension. These spectral changes are discussed in terms of the possible energy deactivation processes.

Santos, Beate S.; de Farias, Patrícia M. A.; de Menezes, Frederico D.; Mariano, Erick L.; de C. Ferreira, Ricardo; Giorgio, Selma; Bosetto, Maira C.; Ayres, Diana C.; Lima, Paulo M.; Fontes, Adriana; de Thomas, André A.; Cesar, Carlos L.

2006-02-01

186

Peripheral blood fibrocytes: new information to explain the dynamics of Leishmania infection  

Scientific Electronic Library Online (English)

Full Text Available Fibrocytes are important for understanding the progression of many diseases because they are present in areas where pathogenic lesions are generated. However, the morphology of fibrocytes and their interactions with parasites are poorly understood. In this study, we examined the morphology of periph [...] eral blood fibrocytes and their interactions with Leishmania (L.) amazonensis . Through ultrastructural analysis, we describe the details of fibrocyte morphology and how fibrocytes rapidly internalise Leishmania promastigotes. The parasites differentiated into amastigotes after 2 h in phagolysosomes and the infection was completely resolved after 72 h. Early in the infection, we found increased nitric oxide production and large lysosomes with electron-dense material. These factors may regulate the proliferation and death of the parasites. Because fibrocytes are present at the infection site and are directly involved in developing cutaneous leishmaniasis, they are targets for effective, non-toxic cell-based therapies that control and treat leishmaniasis.

Roger Magno, Macedo-Silva; Carina de Lima Pereira dos, Santos; Vanessa Alvaro, Diniz; Jorge Jose de, Carvalho; Camila, Guerra; Suzana, Corte-Real.

2014-02-01

187

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 T [...] richomonas 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.

Sergio, Sifontes-Rodríguez; Lianet, Monzote-Fidalgo; Nilo, Castañedo-Cancio; Ana Margarita, Montalvo-Álvarez; Yamilé, López-Hernández; Niurka Mollineda, Diogo; Juan Francisco, Infante-Bourzac; Oliver, Pérez-Martín; Alfredo, Meneses-Marcel; José Antonio Escario, García-Trevijano; Miguel Ángel, Cabrera-Pérez.

188

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in spanish 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 Abstract in english 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 lesion evolution and the primary or recurrent nature of the lesions. In addition, the combined use of IgM titer and Montenegro reactivity is of potential utility in the diagnosis of early lesions.

Maricel, Labrada; Kristen, Weigle; Liliana, Valderrama; Nancy G., Saravia.

1989-09-01

189

Estudo, ao microscópio óptico e eletrônico, do rim de caes natural e experimentalmente infectados com Leishmania (Leishmania) chagasi Optical and electron microscopical studies of canine kidney naturally and experimentally infected with Leishmania (Leishmania) chagasi  

OpenAIRE

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 ...

Washington Luiz Tafuri; Marilena Suzan Marques Michalick; Magno Dias; Odair Genaro; Virginia Hora Rios Leite; Alfredo José Afonso Barbosa; Eduardo Alves Bambirra; Carlos Alberto Da Costa; Maria Norma de Melo; Wilson Mayrink

1989-01-01

190

An outbreak of american cutaneous leishmaniasis (Leishmania braziliensis braziliensis) in a periurban area of Rio de Janeiro city, Brazil: clinical and epidemiological studies / Um surto de leishmaniose cutânea americana (Leishmania braziliensis braziliensis) numa área periurbana da cidade do Rio de Janeiro, Brasil: estudos clínicos e epidemiológicos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese De julho de 1984 a setembro de 1986, 105 casos de leishmaniose cutânea foram estudados numa localidade situada na imediata vizinhança da área urbanizada da região metropolitana da cidade do Rio de Janeiro. A ocupação do sítio deu-se aproximadamente há 20 anos, mas os primeiros casos foram registrado [...] s somente seis meses antes do início de nosso estudo. Os casos eram quase que exclusivamente cutâneos, da forma clínica ulcerada com um e seis meses de evolução. O teste de Montenegro foi positivo em todos os casos e anticorpos antileishmania foram detectados por imunofluorescência indireta em 74,3% dos pacientes. A demonstração do parasito foi obtida em 69,5%. Animais domésticos infectados foram facilmente encontrados: 32% dos cães examinados e 30,8% dos equinos mostravam presença de leishmânia em lesões ulceradas. Parasitos isolados, tanto de casos humanos como de cães e equinos, foram imulogicamente caracterizados e identificados com L. b. braziliensis. Da população de flebotomíneos encontrados 73% eram de Lutzomyia intermedia capturados principalmente com iscas humanas e de animais domésticos. Nossas observações sugerem que esta é uma área de estabelecimento recente da infecção por L. b. braziliensis e que a transmissão ocorre provavelmente tanto no peridomicílio como no interior das habitações. Abstract in english From July 1984 to September 1986, 105 cases of American cutaneous leishmaniasis were studied in a locality closely situated to an urbanized area of the city of Rio de Janeiro, Brazil. Settement in this area was established at least 20 years ago but the first cases were noted six months prior to the [...] beginning of this study. Cases were almost exlusively cutaneous and ulcerated, with one to six months of evolution. Montenegro's skin tests were positive in all cases and anti-Leishmania antibodies were detected by indirect immunofluorescence test in 74.3% of the patients. Parasites were demonstrated in 69.5% of cases. Domestic animals were easily found infected; 32% of the examined dogs and 30.8% of the examined equines were positive to the presence of Leishmania in cutaneous ulcerated lesions. Parasite isolates from human, dog andequines were immunologically characterized and identified as L. b. braziliensis. 73,0% of the sandfly population were Lutzomyia intermedia mainly caught on human baits and on domestic animals. Our observations suggest that this is an area of recent established L. b. braziliensis infection and that transmission probably occurs indoors or outdoors close to the houses.

Manoel P., Oliveira-Neto; Claude, Pirmez; Elizabeth, Rangel; Armando, Schubach; Gabriel, Grimaldi Júnior.

1988-12-01

191

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

International Nuclear Information System (INIS)

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

192

In vitro and in vivo antileishmanial efficacy of a combination therapy of diminazene and artesunate against Leishmania donovani in BALB/c mice / Estudo in vitro e in vivo da eficácia anti leishmaniótica de terapêutica combinada de Diminazene e Artesunate contra Leishmania donovani em camundongos Balb/c  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A atividade in vitro e in vivo de Diminazene (Dim), Artezunate (Art) e a combinação Dim e Art (Dim-Art) contra Leishmania donovani foi comparada com a droga de referência Anfotericina B. IC50 da Dim-Art foi 2,28 ± 0,24 µg/mL enquanto aquelas de Dim e Art foram 9,16 ± 0,3 µg/mL e 4,64 ± 0,48 µg/mL re [...] spectivamente. O IC50 da Anfotericina B foi 0,16 ± 0,32 µg/mL contra a fase estacionária de promastigotas. A avaliação in vivo do modelo de L. donovani em camundongos Balb/c indicou que os tratamentos com a terapêutica de drogas combinadas em doses de 12,5 mg/kg por 28 dias consecutivos significantemente (p Abstract in english The in vitro and in vivo activity of diminazene (Dim), artesunate (Art) and combination of Dim and Art (Dim-Art) against Leishmania donovani was compared to reference drug; amphotericin B. IC50 of Dim-Art was found to be 2.28 ± 0.24 µg/mL while those of Dim and Art were 9.16 ± 0.3 µg/mL and 4.64 ± 0 [...] .48 µg/mL respectively. The IC50 for Amphot B was 0.16 ± 0.32 µg/mL against stationary-phase promastigotes. In vivo evaluation in the L. donovani BALB/c mice model indicated that treatments with the combined drug therapy at doses of 12.5 mg/kg for 28 consecutive days significantly (p

Joshua Muli, Mutiso; John Chege, Macharia; Mustafa, Barasa; Evans, Taracha; Alain J., Bourdichon; Michael M., Gicheru.

2011-06-01

193

Leishmania Exploit Sex  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. Leishmania are the last of the three major groups of trypanosomatid parasites to give up their secret--a healthy capacity for genetic exchange.

Michael Miles (London School of Hygiene and Tropical Medicine; )

2009-04-10

194

Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis / A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA) ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respost [...] as terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia) guyanensis. MÉTODOS: 185 pacientes foram selecionados, conforme critérios de elegibilidade, e distribuídos, aleatoriamente, em 3 grupos - 2 com 74 enfermos e outro com 37 - que receberam, respectivamente, antimoniato de meglumina, isotionato de pentamidina e anfotericina B em doses, períodos e vias de administração padronizados. Os enfermos foram reexaminados um, dois e seis meses após o final dos tratamentos. RESULTADOS: Não houve diferença entre os grupos terapêuticos em relação ao sexo, idade, número ou local das lesões. A análise por intenção de tratar (ITT) mostrou eficácias de 58,1% para a pentamidina e 55,5% para o antimoniato (p=0,857). O grupo da anfotericina B foi analisado separadamente, pois 28 (75,7%) pacientes negaram-se a continuar no estudo após a randomização. Eventos adversos leves ou moderados foram relatados por 74 (40%) pacientes, principalmente artralgia (20,3%), para o grupo do antimoniato, e dor (35,1%) ou enduração (10,8%) no local das injeções para a pentamidina. CONCLUSÕES: A pentamidina tem eficácia similar ao antimonial pentavalente para o tratamento da LTA ocasionada por L. guyanensis. Face aos baixos resultados de eficácia apresentados por ambas as drogas, necessita-se, com urgência, investigar novas opções terapêuticas para esta enfermidade. Abstract in english FUNDAMENTALS: American tegumentary leishmaniasis (ATL) treatment remains a challenge, since most available drugs are injectable and only a small number of comparative, randomized clinical trials have been performed to support their use. Moreover, treatment outcome may depend on the causative species [...] of Leishmania. OBJECTIVES: To evaluate and compare the efficacy and tolerability of meglumine antimoniate, pentamidine isethionate, and amphotericin B in the treatment of ATL caused by Leishmania (Viannia) guyanensis. METHODS: 185 patients were selected according to the eligibility criteria and randomly allocated into three groups - two groups with 74 patients each, and one group with 37 patients, which underwent meglumine, pentamidine and amphotericin B treatment, respectively. Doses, mode of administration and time periods of treatment followed the current recommendations for each drug. Patients were re-examined one, two and six months after completion of treatment. RESULTS: No differences were observed among the therapeutic groups in relation to gender, age, number or site of lesions. Intention-to-treat (ITT) analysis showed efficacy of 58.1% for pentamidine and 55.5% for meglumine (p=0.857). The amphotericin B group was analyzed separately, since 28 patients (75.7%) in this group refused to continue participating in the study. Mild or moderate adverse effects were reported by 74 (40%) patients, especially arthralgia (20.3%) in the meglumine group, and pain (35.1%) or induration (10.8%) at the site of injection in the pentamidine group. CONCLUSION: Pentamidine and meglumine show similar efficacy in the treatment of ATL caused by L. guyanensis. Given the low efficacy of both drugs, there is an urgent need for new therapeutical approaches.

Leandro Ourives, Neves; Anette Chrusciak, Talhari; Ellen Priscilla Nunes, Gadelha; Roberto Moreira da, Silva Júnior; Jorge Augusto de Oliveira, Guerra; Luiz Carlos de Lima, Ferreira; Sinésio, Talhari.

1092-11-01

195

Estudo clínico randomizado comparando antimoniato de meglumina, pentamidina e anfotericina B para o tratamento da leishmaniose cutânea ocasionada por Leishmania guyanensis A randomized clinical trial comparing meglumine antimoniate, pentamidine and amphotericin B for the treatment of cutaneous leishmaniasis by Leishmania guyanensis  

Directory of Open Access Journals (Sweden)

Full Text Available FUNDAMENTOS: O tratamento da leishmaniose tegumentar americana (LTA ainda constitui desafio, pois a maioria dos medicamentos é injetável e têm-se poucos ensaios clínicos randomizados comparando a eficácia das drogas. Além disso, é provável que as espécies de Leishmania tenham influência nas respostas terapêuticas. OBJETIVOS: Avaliar e comparar a eficácia e a segurança dos esquemas de tratamento na LTA, ocasionada por Leishmania (Viannia guyanensis. MÉTODOS: 185 pacientes foram selecionados, conforme critérios de elegibilidade, e distribuídos, aleatoriamente, em 3 grupos - 2 com 74 enfermos e outro com 37 - que receberam, respectivamente, antimoniato de meglumina, isotionato de pentamidina e anfotericina B em doses, períodos e vias de administração padronizados. Os enfermos foram reexaminados um, dois e seis meses após o final dos tratamentos. RESULTADOS: Não houve diferença entre os grupos terapêuticos em relação ao sexo, idade, número ou local das lesões. A análise por intenção de tratar (ITT mostrou eficácias de 58,1% para a pentamidina e 55,5% para o antimoniato (p=0,857. O grupo da anfotericina B foi analisado separadamente, pois 28 (75,7% pacientes negaram-se a continuar no estudo após a randomização. Eventos adversos leves ou moderados foram relatados por 74 (40% pacientes, principalmente artralgia (20,3%, para o grupo do antimoniato, e dor (35,1% ou enduração (10,8% no local das injeções para a pentamidina. CONCLUSÕES: A pentamidina tem eficácia similar ao antimonial pentavalente para o tratamento da LTA ocasionada por L. guyanensis. Face aos baixos resultados de eficácia apresentados por ambas as drogas, necessita-se, com urgência, investigar novas opções terapêuticas para esta enfermidade.FUNDAMENTALS: American tegumentary leishmaniasis (ATL treatment remains a challenge, since most available drugs are injectable and only a small number of comparative, randomized clinical trials have been performed to support their use. Moreover, treatment outcome may depend on the causative species of Leishmania. OBJECTIVES: To evaluate and compare the efficacy and tolerability of meglumine antimoniate, pentamidine isethionate, and amphotericin B in the treatment of ATL caused by Leishmania (Viannia guyanensis. METHODS: 185 patients were selected according to the eligibility criteria and randomly allocated into three groups - two groups with 74 patients each, and one group with 37 patients, which underwent meglumine, pentamidine and amphotericin B treatment, respectively. Doses, mode of administration and time periods of treatment followed the current recommendations for each drug. Patients were re-examined one, two and six months after completion of treatment. RESULTS: No differences were observed among the therapeutic groups in relation to gender, age, number or site of lesions. Intention-to-treat (ITT analysis showed efficacy of 58.1% for pentamidine and 55.5% for meglumine (p=0.857. The amphotericin B group was analyzed separately, since 28 patients (75.7% in this group refused to continue participating in the study. Mild or moderate adverse effects were reported by 74 (40% patients, especially arthralgia (20.3% in the meglumine group, and pain (35.1% or induration (10.8% at the site of injection in the pentamidine group. CONCLUSION: Pentamidine and meglumine show similar efficacy in the treatment of ATL caused by L. guyanensis. Given the low efficacy of both drugs, there is an urgent need for new therapeutical approaches.

Leandro Ourives Neves

2011-12-01

196

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

Directory of Open Access Journals (Sweden)

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.

Mimori Tatsuyuki

2006-09-01

197

Características epidemiológicas da leishmaniose tegumentar americana em uma região endêmica do Estado da Bahia: III. Fauna flebotomínica / Epidemiological characteristics of American tegumentary leishmaniasis in an endemic region of the State of Bahia: III. Phlebotomine fauna  

Scientific Electronic Library Online (English)

Full Text Available A fauna flebotomínica da região de Três Braços, uma área endêmica de leishmaniose cutânea-mucosa localizada no sudeste do Estado da Bahia, na região cacaueira, é muito variada. Foram identificadas 30 espécies de Lutzomyia em 13.535 exemplares coletados entre os anos de 1976 e 1984. Lu. withmani foi [...] a espécie altamente predominante no ambiente peridoméstico e no interior das residências, com percentuais de 99,0 e 97,5, respectivamente. Na floresta, as espécies predominantes foram Lu. ayrozai e Lu. yuilli, aparecendo Lu. whitmani com apenas 1,0% do total de exemplares examinados. Lu. flaviscutellata, vetor comprovado da Leishmania mexicana amazonensis, foi também coletada em baixos índices. Lu. wellcomei, vetor da L. braziliensis braziliensis na Serra dos Carajás, Pará, Brasil, não foi encontrada na região de Três Braços onde o parasito causando infecções humanas é predominantemente L. b. braziliensis. Embora não se tenha encontrado infecção natural por promastigotas em 1.832 fêmeas de diversas espécies examinadas, discute-se a possibilidade de Lu. whitmani ser um vetor da L.b. braziliensis na região, mantendo, provavelmente, a transmissão entre o cão e o homem. Abstract in english The phlebotomine fauna is highly varied in três Braços, an endemic area american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of Bahia State, brazil. Thirty species of the Lutzomyia genus were identified in 13,535 spcecimens collected between 1976 and 1984. Lutzomyi [...] a whitmani was the dominant species accounting for 99% or flies in the periodomicile and 97.5% of those caught in homes. In the forest the predominant species were Lu. ayrozai and Lu. yulli. Lu whitmani accounted for only 1.0% of the specimens examined. Lu. flaviscutellata, the proven vector of Leishmania mexicana amazonensis, was also collected in small numbers, I.u. wellcomei, a known vector of L. braziliensis braziliensis in the Serra dos Carajás, Pará, Brazil was not encountered in the Três Braços region where the parasite causing human infections is usually L.b. braziliensis. Although we have not encountered a natural infection with leishmanial promastigotes in 1.832 females of the various species examined, we discuss the probability that Lu. whitmani is the vector of L.b braziliensis in the region mantaining transmission in dogs and man.

Julio A., Vexenat; Air C., Barreto; César A. Cuba, Cuba; Philip Davis, Marsden.

1986-09-01

198

Infecção natural de Lutzomyia longipalpis por Leishmania sp. em Teresina, Piauí, Brasil Natural infection of Lutzomyia longipalpis by Leishmania sp. in Teresina, Piauí State, Brazil  

OpenAIRE

No Brasil, o controle do vetor Lutzomyia longipalpis é uma das principais estratégias utilizadas para limitar a expansão da leishmaniose visceral americana. Entretanto, poucos são os estudos sobre a infecção natural destes flebotomíneos por espécies de Leishmania. Um estudo sobre a infecção natural de Lu. longipalpis por Leishmania sp. foi realizado no bairro Bela Vista, Teresina, Piauí, um dos principais focos urbanos da leishmaniose visceral americana no Brasil. Entre fevereiro d...

Silva, Jackellyne Geo?rgia Dutra E.; Werneck, Guilherme L.; Cruz, Maria Do Socorro Pires E.; Carlos Henrique Nery Costa; Ivete Lopes de Mendonça

2007-01-01

199

DISEÑO Y PRODUCCIÓN DE UNA HERRAMIENTA MOLECULAR PARA EL ESTUDIO DEL N-TERMINAL DE LA NICOTINAMIDA MONONUCLEÓTIDO ADENILIL TRANSFERASA (NMNAT) EN Leishmania braziliensis / DESIGN AND PRODUCTION OF A MOLECULAR TOOL TO STUDY OF N-TERMINAL NICOTINAMIDE MONONUCLEOTIDE ADENYLYL TRANSFERASE (NMNAT) IN Leishmania braziliensis / DESIGN E PRODUÇÃO DE UMA FERRAMENTA MOLECULAR PARA O ESTUDO DO TERMINALN DA NICOTINAMIDA CICLASE MONONUCLEÓTIDO TRANSFERASE (NMNAT) EM Leishmania braziliensis  

Scientific Electronic Library Online (English)

Full Text Available Leishmania braziliensis é um parasita protozoário que causa a maioria dos casos de leishmaniose cutânea em pelo menos 15 países das Américas. A Organização Mundial de Saúde (OMS) informou que cerca de 12 milhões de pessoas estão infectadas em todo o mundo e esse número aumenta a cada ano. Devido ao [...] delicado problema de saúde pública decorrentes da prevalência desta doença é necessário estudar o metabolismo do parasita. A este respeito temos estudado a proteína NMNAT deste parasita, que é uma enzima central no metabolismo de todos os organismos de estar envolvido na produção de NAD+, um importante cofator em reações redox de processos centrais de celulares metabolismo. No L. braziliensis NMNAT encontrou uma seqüencia de 43 aminoácidos no terminal N homologia com a proteína faltando host. Este estudo produziu anticorpos IgG específicos para esta seqüência, usando como peptídeos de antígeno contendo a seqüência mencionada. Os anticorpos obtidos mostraram um reconhecimento da NMNAT L. braziliensis recombinantes por meio de julgamento por western blot. Abstract in spanish Leishmania braziliensis es un parásito protozoario causante de la mayor parte de casos de leishmaniasis cutánea en al menos quince países del continente americano. La Organización Mundial de la Salud (OMS) ha reportado que cerca de doce millones de personas están infectadas en el mundo y que este nú [...] mero aumenta cada año. Debido al delicado problema de salud pública derivado de la prevalencia de esta enfermedad se hace necesario el estudio del metabolismo de este parásito. En tal sentido se ha estudiado la proteína NMNAT de este parásito, la cual es una enzima central del metabolismo de todos los organismos al estar encargada de la síntesis del NAD+, un importante cofactor en reacciones redox de procesos centrales del metabolismo celular. En la NMNAT de L. braziliensis se ha encontrado una secuencia de 44 aminoácidos en el extremo N-terminal carente de homología con la proteína del hospedero. En este estudio se produjeron anticuerpos IgG específicos contra esta secuencia, utilizando como antígenos péptidos que contuvieran la secuencia mencionada. Los anticuerpos obtenidos mostraron un reconocimiento de la NMNAT recombinante de L. braziliensis mediante ensayo por western blot. Abstract in english Leishmania braziliensis is a protozoan which is cause of the most of the cutaneous leishmaniasis cases in at least 15 countries from America. World Health Organization (WHO) has reported that around 12 millions of people are infected in the world and this number increase every year. Because of the d [...] elicate problem of public health due to the prevalence of this disease, it is necessary the metabolism study in this parasite. In this way has been studied NMNAT protein of the parasite, which is a central enzyme of the metabolism of all organisms, since it is in charge of synthesizing NAD+, an important cofactor in oxidation-reduction reactions of central processes in the cellular metabolism. In The NMNAT of L. has been found a 43 amino acids sequence in the N terminal, which does not have homology with the protein in the human host. In this study were produced IgG antibodies against this sequence, using like antigens peptides that had the mentioned sequence. The produced antibodies recognized the recombinant NMNAT of L. braziliensis through western blot assay.

Jesús D, Castaño; Zuly J, Rivera; María H, Ramírez.

2012-08-01

200

In vitro effects of triterpenic acids from olive leaf extracts on the mitochondrial membrane potential of promastigote stage of Leishmania spp.  

Science.gov (United States)

Protozoan diseases, such as leishmaniasis, are a cause of considerable morbidity throughout the world, affecting millions every year. In this study, two triterpenic acids (maslinic and oleanolic acids) were isolated from Tunisian olive leaf extracts and their in vitro activity against the promastigotes stage of Leishmania (L.) infantum and Leishmania (L.) amazonensis was investigated. Maslinic acid showed the highest activity with an IC50 of 9.32 ± 1.654 and 12.460 ± 1.25 ?g/ml against L. infantum and L. amazonensis, respectively. The mechanism of action of these drugs was investigated by detecting changes in the phosphatidylserine (PS) exposure, the plasma membrane permeability, the mitochondrial membrane potential and the ATP level production in the treated parasites. By using the fluorescent probe SYTOX® Green, both triterpenic acids showed that they produce a time-dependent plasma membrane permeabilization in the treated Leishmania species. In addition, spectrofluorimeteric data revealed the surface exposure of PS in promastigotes. Both molecules reduced the mitochondrial membrane potential and decreased the ATP levels to 15% in parasites treated with IC90 for 24h. We conclude that the triterpenic acids tested in this study, show potential as future therapeutic alternative against leishmaniasis. Further studies are needed to confirm this. PMID:25442278

Sifaoui, Ines; López-Arencibia, Atteneri; Martín-Navarro, Carmen Maria; Ticona, Juan Carlos; Reyes-Batlle, María; Mejri, Mondher; Jiménez, Antonio Ignacio; Lopez-Bazzocchi, Isabel; Valladares, Basilio; Lorenzo-Morales, Jacob; Abderabba, Manef; Piñero, José E

2014-10-15

201

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

Scientific Electronic Library Online (English)

Full Text Available As formas de cultura de 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) e L. mexicana amazonensis (H-JMMO, M-JOF, H-21, H-PLL, M-1696) foram testadas com as seguintes lectinas: Canavalia ensiformis, Ricinus communis- [...] 120, Axinella polypoides, Phaseolus vulgaris, Evonymus europaeus, Lotus tetragonolobus, Dolichos biflorus, Aaptos papilata II, Laburnum alpinum, Ulex europaeus, Arachis hypogaea and Soja hispida. Todas as cepas de leishmania aglutinadas por C. ensiformis, R. communis-120 e A. polypoides. Nenhuma reação de aglutinação foi observada com P. vulgaris, D. biflorus, A. papillata II, E. europaeus e L. tetragonolobus. Apenas L. m. pifanoi e as cepas H-JMMO e M-JOF de L. m. amazonensis mostravam reações de aglutinação com S. hispida, U. europaeus, l. alpinum e A. hypogaea enquanto as cepas LRC L-94 e M-379 de L. m. mexicana; H-LSS, LRC L-77, L-1 e M-2903 de L. b. braziliensis bem como as cepas H-PLL, H-21, M-1696 não mostraram nenhuma reação de aglutinação com estas quatro lectinas. Assim, as variações intra-específicas encontradas pelos testes de aglutinação por lectinas em cepas de leishmanias isoladas de casos de leishmaniose tegumentar não permitem estabelecer uma correlação entre formas clínicas e cepas isoladas. Por outro lado, estes testes mostram que a cepa de L. mexicana pifanoi apresenta reações idênticas às de duas cepas de L. mexicana amazonensis, não se podendo assim diferenciá-la por esta técnica. Pelo teste de aglutinação por lectina, empregado neste trabalho, podemos agrupar as cepas estudadas em dois grupos, mas não sabemos até o presente momento qual o significado destas variações intra-específicas em leishmanias isoladas de casos de leishmaniose cutânea do novo mundo. Abstract in english 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.

J., Schottelius; S. C. Gonçalves da, Costa.

1982-03-01

202

Susceptibility of laboratory-reared female Lutzomyia longipalpis (Lutz & Neiva, 1912) to infection by different species and strains of Leishmania Ross, 1903  

OpenAIRE

A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all (18/18) of the specimens examined. A lower infection rate of 37 per cents (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13 per cents (6/...

Da Silva, Ana Lu?cia F. F.; Paul Williams; Maria Norma de Melo; Wilson Mayrink

1990-01-01

203

Anti-HIV drugs, lopinavir/ritonavir and atazanavir, modulate innate immune response triggered by Leishmania in macrophages: The role of NF-?B and PPAR-?.  

Science.gov (United States)

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-? 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-? 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. PMID:25545854

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

2015-02-01

204

Leishmania (Viannia braziliensis em cães naturalmente infectados Leishmania (Viannia braziliensis in naturally infected dogs  

Directory of Open Access Journals (Sweden)

Full Text Available Foram estudados oito cães provenientes do Município de Maricá (RJ, com lesões sugestivas de leishmaniose tegumentar americana por métodos parasitológicos e sorológicos. Leishmania spp foi encontrada em seis cães através do cultivo in vitro. Anticorpos específicos foram detectados em seis animais pelo ELISA e em dois pela imunofluorescência indireta. Cinco isolados caninos analisados apresentaram zimodema similar a Leishmania (Viannia braziliensis. Sugere-se que cães clinicamente suspeitos sejam acompanhados periodicamente, na tentativa de confirmar o diagnóstico da leishmaniose tegumentar canina.Eight dogs from Maricá Municipality (RJ, with suggestive lesion of american tegumentary leishmaniasis were studied by parasitological and serological methods. Leishmania spp was found in six dogs by in vitro cultivation. Specific antibodies were detected in six dogs by ELISA and in two by indirect immunofluorescence. Five canine isolates were found to belong to the same zymodeme as Leishmania (Viannia braziliensis. The authors suggest that clinically suspect dogs should be followed-up in an attempt to confirm the diagnostic of canine tegumentary leishmaniasis.

Maria de Fátima Madeira

2003-10-01

205

Características clínicas da leishmaniose tegumentar em crianças de 0 a 5 anos em uma área endêmica de Leishmania (Viannia) braziliensis / Clinical findings of tegumentary leishmaniasis in children under five years of age in an endemic area of Leishmania (Viannia) braziliensis  

Scientific Electronic Library Online (English)

Full Text Available Para caracterizar a clínica da leishmaniose tegumentar em crianças de 0 a 5 anos de idade, foram avaliadas, retrospectivamente, 4.464 fichas clínicas do Centro de Saúde de Corte de Pedra, Presidente Tancredo Neves, Bahia, Brasil, área endêmica de leishmaniose tegumentar americana, entre maio de 1987 [...] e dezembro de 1995. Foram registrados neste período 4.275 casos novos de leishmaniose, dos quais, 491 (11,5%) correspondiam a crianças de 0 a 5 anos. A razão entre gênero masculino e feminino nas crianças foi 1,1:1. A forma clínica predominante foi a cutânea (98%) e as lesões ulceradas foram as mais freqüentes (99%). A localização das lesões ocorreu, principalmente, acima da cintura (p Abstract in english A retrospective study was performed in a field clinic to characterize the clinical findings of tegumentary leishmaniasis in children from 0 to 5 years old. The clinical records of 4,464 patients were analyzed at the Primary Health Center of Corte de Pedra, Presidente Tancredo Neves, Bahia, Brazil, f [...] rom May 1987 to December 1995. Four hundred and ninety one (11.8%) children were identified among 4,275 new cases of tegumentary leishmaniasis registered at this Unit. The gender ratio (M:F) for children under six years was 1.1:1. Cutaneous lesions predominated (98%), mainly skin ulcers (99%) located above the waist (p

Julia, Ampuero; Vanize, Macêdo; Philip, Marsden.

2006-02-01

206

Combinations of ascaridole, carvacrol, and caryophyllene oxide against Leishmania.  

Science.gov (United States)

To date there are no vaccines against Leishmania and chemotherapy remains the mainstay for the control of leishmaniasis. The drugs currently used for leishmaniasis therapy are significantly toxic, expensive, and result in a growing frequency of refractory infections. In this study, we evaluated the effect of combinations of the main components of essential oil from Chenopodium ambrosioides (ascaridole, carvacrol, and caryophyllene oxide) against Leishmaniaamazonensis. Anti-leishmanial effects of combinations of pure compounds were evaluated in vitro and the fractional inhibitory concentration (FIC) indices were calculated. BALB/c mice infected with L. amazonensis were treated with different concentrations of ascaridole-carvacrol combinations by intralesional doses every 4 days. Disease progression and parasite burden in infected tissues were determined. In vitro experiments showed a synergistic effect of the combination of ascaridole-carvacrol against promastigotes of Leishmania with a FIC index of 0.171, while indifferent activities were observed for ascaridole-caryophyllene oxide (FIC index=3.613) and carvacrol-caryophyllene oxide (FIC index=2.356) combinations. The fixed ratio method showed that a 1:4 ascaridole-carvacrol ratio produced a better anti-protozoal activity on promastigotes, lower cytotoxicity, and synergistic activity on intracellular amastigotes (FIC index=0.416). Significant differences (p<0.05) in lesion size and parasite burden were demonstrated in BALB/c mice experimentally infected and treated with the ascaridole-carvacrol combinations compared with control animals. Carvacrol showed significant higher anti-radical activity in the DPPH assay compared with caryophyllene oxide. Electron spin resonance spectroscopy in combination with spin trapping suggested the presence of carbon-centered radicals after activation of ascaridole by Fe(2+). The intensity of the signals is preferably decreased upon addition of carvacrol. The ascaridole-carvacrol combination could represent a future alternative to monotherapeutic anti-leishmanial agents. PMID:25697866

Pastor, Jacinta; García, Marley; Steinbauer, Silvia; Setzer, William N; Scull, Ramón; Gille, Lars; Monzote, Lianet

2015-05-01

207

Intranasal Vaccination with Leishmanial Antigens Protects Golden Hamsters (Mesocricetus auratus) Against Leishmania (Viannia) braziliensis Infection  

Science.gov (United States)

Background Previous results have shown that oral and intranasal administration of particulate Leishmania (Leishmania) amazonensis antigens (LaAg) partially protects mice against L. amazonensis infection. However, vaccination studies on species of the subgenus Viannia, the main causative agent of cutaneous and mucosal leishmaniasis in the Americas, have been hampered by the lack of easy-to-handle bio-models that accurately mimic the human disease. Recently, we demonstrated that the golden hamster is an appropriate model for studying the immunopathogenesis of cutaneous leishmaniasis caused by L. (Viannia) braziliensis. Using the golden hamster model, our current study investigated whether the protective effect of intranasal immunisation with LaAg can be extended to L. braziliensis infection. Methodology/Principal Findings Golden hamsters vaccinated with either two intranasal (IN) doses of LaAg (10 µg) or two intramuscular doses of LaAg (20 µg) were challenged 2 weeks post-vaccination with L. braziliensis. The results showed that IN immunisation with LaAg significantly reduced lesion growth and parasitic load as well as serum IgG and IgG2 levels. At the experimental endpoint on day 114 post-infection, IN-immunised hamsters that were considered protected expressed IFN-? and IL10 mRNA levels that returned to uninfected skin levels. In contrast to the nasal route, intramuscular (IM) immunisation failed to provide protection. Conclusions/Significance These results demonstrate for the first time that the nasal route of immunisation can induce cross protection against L. braziliensis infection. PMID:25569338

da Silva-Couto, Luzinei; Ribeiro-Romão, Raquel Peralva; Saavedra, Andrea Franco; da Silva Costa Souza, Beatriz Lilian; Moreira, Otacílio Cruz; Gomes-Silva, Adriano; Rossi-Bergmann, Bartira; Da-Cruz, Alda Maria; Pinto, Eduardo Fonseca

2015-01-01

208

Heterorhabditis amazonensis RSC5 (Rhabditida: Heterorhabditidae) movement and host recognition / Desplazamiento y capacidad de búsqueda del nematodo entomopatógeno nativo Heterorhabditis amazonensis RSC5 (Rhabditida: Heterorhabditida)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish La respuesta de Heterorhabditis amazonensis RSC5 en comparación con otras especies de nematodos entomopatógenos como Steinernema carpocapsae All y Steinernema riobrave 355, a los compuestos liberados por diferentes hospederos (Galleria mellonella, Mycotretus apicalis y Tenebrio molitor) y su nivel d [...] e virulencia a estos insectos fue evaluada. Las pruebas se realizaron en placas de Petri con agar-agua 2% para determinar el movimiento de los nematodos con y sin posibilidad de escogencia por diferentes hospederos. Se cuantificó la proximidad de juveniles infectivos (JIs) al hospedero como una fuente de atracción. Con el fin de determinar el desplazamiento de JIs en una condición similar al suelo, un ensayo se llevó a cabo en un área con arena. Los nematodos fueron virulentos para los hospederos. Cuando los nematodos e insectos fueron puestos en agar-agua, JIs se movieron hacia el estímulo, con preferencia de H. amazonensis a ciertos insectos. En la arena, S. carpocapsae causó menor mortalidad (70% ± 8,9 para G. mellonella) que H. amazonensis y S. riobrave (80% ± 6,5 y 99% ± 0,0). Heterorhabditis amazonensis fue capaz de encontrar y elegir a sus hospederos (G. mellonella y T. molitor) similar al comportamiento de S. riobrave y localizar sus hospederos con más eficacia que S. carpocapsae. De este modo, la virulencia de H. amazonensis fue similar a S. riobrave y esta característica podría ser promisoria para introducir esta especie nativa en programas de manejo integrado de plagas. Abstract in english Response of Heterorhabditis amazonensis RSC5 to compounds released by different host insects and its virulence level to several insect hosts like Galleria mellonella, Mycotretus apicalis and Tenebrio molitor were evaluated in this study, and compared with other entomopathogenic nematode species like [...] Steinernema carpocapsae All and Steinernema riobrave 355. Tests were performed in Petri dishes with agar-water 2% to determine nematode movement toward the insect with and without opportunity of choosing different insect hosts. Evaluations were made quantifying the proximity of infective juveniles (IJs) to the insect as a source of allurement. In order to determine the displacement of IJs in a closed soil condition, a test was carried out in an arena with sand. The nematode was virulent to the target insects. When nematode and insect were released on agar-water, IJs moved toward the stimulus, with H. amazonensis howing preference for certain insects. In the arena with sand S. carpocapsae caused lower insect mortality (70% ± 8.9 for G. mellonella) than H. amazonensis and S. riobrave (80% ± 6.5 and 99% ± 0.0). Heterorhabditis amazonensis was able to find and choose its hosts (G. mellonella and T. molitor), similarly to S. riobrave behavior, and located them more effectively than S. carpocapsae. The virulence of H. amazonensis was thus similar to S. riobrave, and this characteristic could be promising to introduce this native species in integrated pest management programs.

VANESSA, ANDALÓ; GRAZIELLE, FURTADO MOREIRA; ALCIDES, MOINO JUNIOR.

2014-06-01

209

Miocardite crônica em um cão naturalmente infectado com Leishmania (Leishmania) infantum chagasi: aspectos clínicos e patológicos / Chronic myocarditis in a dog naturally infected by Leishmania (Leishmania) infantum chagasi: clinical and pathological aspects  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A leishmaniose visceral (LV) é uma doença infecciosa crônica frequentemente fatal causada pela Leishmania infantum chagasi nas Américas. A enfermidade pode acometer vários órgãos, determinando diferentes manifestações clínicas. Contudo o envolvimento do coração raramente tem sido reportado em cães i [...] nfectados por Leishmania sp. Dessa forma, descreve-se um caso de miocardite crônica com repercussões clínicas e patológicas em um cão naturalmente infectado por Leishmania infantum chagasi. A positividade para Leishmaniose Visceral foi determinada pela presença de anticorpos antiLeishmania sp. nos testes sorológicos (RIFI, ELISA e DPP) e confirmada por visualização de formas amastigotas de Leishmania sp. em punção aspirativa do linfonodo poplíteo. O exame cardiovascular revelou alterações radiográficas, eletrocardiográficas, na pressão arterial e nos biomarcardores cardíacos. Após eutanásia, amostras de tecido cardíaco foram avaliadas histologicamente e submetidas à imunomarcação, onde foi observado infiltrado mononuclear (plasmo-histiolinfocitário), com presença de estruturas arredondadas de coloracão marrom-amareladas (imunomarcadas), indicando formas amastigotas de Leishmania infantum chagasi no miocárdio. Os aspectos etiopatogênicos da leishmaniose visceral sobre o miocárdio neste caso podem estar relacionados tanto à presença do parasita quanto à resposta "reacional inespecífica" do tecido à agressão do parasita no organismo. Todavia ainda não se sabem se as cepas de Leishmania infantum chagasi da região semiárida paraibana apresentam algum tropismo por tecido cardíaco ou se induzem a reação imunológica cruzada, com implicações clínicas. Abstract in english Visceral leishmaniasis (VL) is a chronic, often fatal infectious disease caused by Leishmania infantum chagasi in the Americas. The disease can affect many organs and may express different clinical forms. However, the involvement of the heart has rarely been reported in dogs infected by Leishmania s [...] p. Thus, we describe a case of chronic myocarditis with clinical and pathological effects in a dog naturally infected by Leishmania infantum chagasi. Positivity for Visceral Leishmaniasis was determined by the presence of anti-Leishmania sp. in serological tests (IFAT, ELISA and DPP) and confirmed by visualization of amastigote forms of the parasite in the popliteal lymph node aspiration samples. The cardiovascular clinical examination showed changes in the radiographic, ECG, blood pressure and heart biomarkers. After euthanasia, heart tissue samples were histologically examined and underwent our immunohistochemistry assessment, where mononuclear infiltrate was observed (plasma cells, lymphocytes and macrophages) with the presence of rounded brownish-yellow (immunomarked) cells, indicating amastigotes of Leishmania infantum chagasi within the myocardium. The etiopathogenic aspects of visceral leishmaniasis in the myocardium in this case may be related either to the presence of the parasite or the "nonspecific reactive" response of the tissue attributable to the aggression of the parasite in the body. However, it is not known if the strains of Leishmania infantum chagasi found in the semi-arid of Paraíba have some tropism for cardiac tissue or if they induce immunological cross-reaction with clinical implications.

R.S., Mendes; T.A., Gurjão; L.M., Oliveira; V.L., Santana; W.L., Tafuri; J.R.S., Santos; A.F.M., Dantas; A.P., Souza.

2014-02-01

210

RNA polymerase I promoter and splice acceptor site recognition affect gene expression in non-pathogenic Leishmania species  

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Full Text Available Leishmania (Sauroleishmania tarentolae has biotechnological potential for use as live vaccine against visceral leishmaniasis and as a system for the over expression of eukaryotic proteins that possess accurate post-translational modifications. For both purposes, new systems for protein expression in this non-pathogenic protozoan are necessary. The ribosomal RNA promoter proved to be a stronger transcription driver since its use yielded increased levels of recombinant protein in organisms of both genera Trypanosoma or Leishmania. We have evaluated heterologous expression systems using vectors with two different polypyrimidine tracts in the splice acceptor site by measuring a reporter gene transcribed from L. tarentolae RNA polymerase I promoter. Our data indicate that the efficiency of chloramphenicol acetyl transferase expression changed drastically with homologous or heterologous sequences, depending on the polypyrimidine tract used in the construct and differences in size and/or distance from the AG dinucleotide. In relation to the promoter sequence the reporter expression was higher in heterologous lizard-infecting species than in the homologous L. tarentolae or in the mammalian-infecting L. (Leishmania amazonensis.

Tereza Cristina Orlando

2007-11-01

211

115 kDa serine protease confers sustained protection to visceral leishmaniasis caused by Leishmania donovani via IFN-? induced down-regulation of TNF-? mediated MMP-9 activity.  

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Visceral leishmaniasis caused by the intracellular parasite Leishmania donovani is a major public health problem in the developing world. The emergence of increasing number of L. donovani strains resistance to antimonial drugs recommended worldwide requires the intervention of effective vaccine strategy for treatment of VL. In the present study L. donovani culture derived, soluble, secretory serine protease (pSP) has been shown to be vaccine target of VL. Protection from VL could be achieved by the use of safer vaccine which generally requires an adjuvant for induction of strong Th1 response. To assess the safety, immunogenicity and efficacy of pSP as vaccine candidate in mouse model we used IL-12 as adjuvant. BALB/c mice immunized with pSP+IL-12 were protected significantly from challenged infection even after four months by reducing the parasite load in liver and spleen and suppressed the development of the disease along with an increase in IgG2a antibody level in serum, enhanced delayed type hypersensitivity and strong T-cell proliferation. Groups receiving pSP+IL-12 had an augmented pSP antigen specific Th1 cytokines like IFN-? and TNF-? response with concomitant decrease of Th2 cytokines IL-4 and IL-10 after vaccination. In this study the vaccine efficacy of pSP was further assessed for its prophylactic potential by enumerating matrix metalloprotease-9 (MMP-9) profile which has been implicated in various diseases. MMP-9 associated with different microbial infections is controlled by their natural inhibitors (TIMPS) and by some cytokines. In this study pSP was found to regulate excessive inflammation by modulating the balance between MMP-9 and TIMP-1 expression. This modulatory effect has also been demonstrated by IFN-? mediated down regulation of TNF-? induced MMP-9 expression in activated murine macrophages. This is the first report where a secretory L. donovani serine protease (pSP) adjuvanted with IL-12 could also act as protective imunogen by modifying cytokine mediated MMP-9 expression in experimental VL. These findings elucidate the mechanisms of regulation of MMP-9 following infection of L. donovani in vaccinated animals and thus pave the way for developing new immunotherapeutic interventions for VL. PMID:22440312

Choudhury, Rajdeep; Das, Partha; De, Tripti; Chakraborti, Tapati

2013-01-01

212

Ocular alterations in dogs naturally infected by Leishmania (Leishmania chagasi Alterações oculares em cães infectados naturalmente por Leishmania (Leishmania chagasi  

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Full Text Available Ocular conditions, anti-Leishmania antibodies and total protein of the aqueous humor were studied in dogs naturally infected by Leishmania (Leishmania chagasi. Fifty dogs were analyzed and assigned into two groups of 25 animals each. All animals were submitted to routine ophthalmic exam. Results showed that 76% of the affected animals presented ocular signs, being uveitis the predominant. The mean of total protein in the aqueous humor of animals with uveitis was higher (PEstudaram-se as condições oculares, os anticorpos anti-Leishmania e os valores de proteína total no humor aquoso de cães infectados naturalmente por Leishmania (Leishmania chagasi. Analisaram-se 50 cães, divididos em dois grupos de 25 animais. Todos os animais foram submetidos a exame oftálmico rotineiro. Os resultados mostraram que 76% dos cães infectados apresentaram sinais oculares, sendo a uveíte a alteração predominante. A média de proteína total no humor aquoso dos animais com uveíte foi maior (P<0,05, que a dos animais com outros sinais oculares ou sem qualquer sinal. Os valores de anticorpos anti-L. chagasi obtidos no plasma foram estatisticamente superiores aos encontrados no humor aquoso (P<0,05.

F.L.C. Brito

2006-10-01

213

Potent naphthoquinones against antimony-sensitive and -resistant Leishmania parasites: synthesis of novel ?- and nor-?-lapachone-based 1,2,3-triazoles by copper-catalyzed azide-alkyne cycloaddition.  

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Continuing our screening program for novel anti-parasite compounds, we synthesized seven 1,4-naphthoquinones coupled to 1,2,3-triazoles, five nor-?-lapachone-based 1,2,3-triazoles and ten ?-lapachone-based 1,2,3-triazoles. These and other naphthoquinonoid compounds were evaluated for their activity against promastigote forms of antimony-sensitive and -resistant strains of Leishmania infantum (syn. Leishmania chagasi) and Leishmania amazonensis. The toxicity of these compounds to mammalian cells was also examined. The substances were more potent than an antimonial drug, with IC50 values ranging from 1.0 to 50.7 ?M. Nor-?-lapachone derivatives showed the highest antileishmanial activity, with selectivity indices in the range of 10-15. These compounds emerged as important leads for further investigation as antileishmanial agents. Additionally, one of these compounds exhibited cross-resistance in Sb-resistant Leishmania and could provide a molecular tool for investigating the multidrug resistance mechanisms in Leishmania parasites. PMID:23535320

Guimarães, Tiago T; Pinto, Maria do Carmo F R; Lanza, Juliane S; Melo, Maria N; do Monte-Neto, Rubens L; de Melo, Isadora M M; Diogo, Emilay B T; Ferreira, Vitor F; Camara, Celso A; Valença, Wagner O; de Oliveira, Ronaldo N; Frézard, Frédéric; da Silva, Eufrânio N

2013-05-01

214

Histopathological and immunohistochemical study of the gastrointestinal tract from a dog naturally infected with Leishmania (Leishmania) chagasi: a case report / Histopatologia e imunoistoquímica do trato gastrintestinal em cão naturalmente infectado com Leishmania (Leishmania) chagasi: relato de caso  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Um cão assintomático e naturalmente infectado com Leishmania (L.) chagasi foi sacrificado e fragmentos do estômago, duodeno, jejuno, íleo, ceco e cólon foram coletados para confecção de esfregaços por aposição corados pelo Giemsa ("imprints"). Outros fragmentos foram obtidos e fixados em formol tamp [...] onado a 10% para estudos histopatológicos e imunoistoquímicos. Empregou-se a técnica imunoistoquímica de estreptavidina-peroxidase a qual possibilitou detecção de formas amastigotas de Leishmaniachagasi em todos os segmentos do trato gastrintestinal (TGI). A principal lesão observada foi a reação inflamatória crônica de intensidade variável, localizada principalmente na mucosa e submucosa de todos os segmentos do TGI. O exsudato celular era composto de monócitos, plasmócitos e linfócitos. O estudo imunoistoquímico mostrou a presença de amastigotas de Leishmania em todos os fragmentos do TGI. A pesquisa de parasitas não pôde ser observada de forma satisfatória pela técnica da HE. Concluiu-se que a técnica de imunoistoquímica como diagnóstico da doença no caso de envolvimento gastrintestinal é eficaz. Abstract in english Samples of stomach, duodenum, jejunun, ileum, cecum and colon were collected for Giemsa-smears ("imprints") from one asymptomatic mongrel dog, naturally infected with Leishmania (L) chagasi. Other fragments were obtained and fixed in formalin (10% and buffered) for histopathological and immunohistoc [...] hemical studies. The immunohistochemistry was carried out by a streptavidin-peroxidase technique and it allowed to detect amastigote forms of Leishmania chagasi in the different paraffin gut sections. The principal lesion observed was a discrete to moderate chronic inflammatory reaction in the mucosa and submucosa in all fragments of the gastrointestinal tract (GIT). A chronic cellular exsudate was observed in all GIT tissues and it was composed by mononuclear cells (monocytes, plasmocytes and lymphocytes). A comparison between the two techniques showed that the immunohistochemistry study is the best method to detect amastigote forms of Leishmania.

F.L., Silva; W.L., Tafuri; M.R., Oliveira; Wg. L., Tafuri.

2002-08-01

215

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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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 low. Such low incidence suggests that these hosts has no epidemiological relevance in the study area.

Katia Denise Saraiva Bresciani

2010-06-01

216

Extreme inbreeding in Leishmania braziliensis  

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Leishmania species of the subgenus Viannia and especially Leishmania braziliensis are responsible for a large proportion of New World leishmaniasis cases. The reproductive mode of Leishmania species has often been assumed to be predominantly clonal, but remains unsettled. We have investigated the genetic polymorphism at 12 microsatellite loci on 124 human strains of Leishmania braziliensis from 2 countries, Peru and Bolivia. There is substantial genetic diversity, with an average of 12.4 ± 4.4 alleles per locus. There is linkage disequilibrium at a genome-wide scale, as well as a substantial heterozygote deficit (more than 50% the expected value from Hardy?Weinberg equilibrium), which indicates high levels of inbreeding. These observations are inconsistent with a strictly clonal model of reproduction, which implies excess heterozygosity. Moreover, there is large genetic heterogeneity between populations within countries (Wahlund effect), which evinces a strong population structure at a microgeographic scale. Our findings are compatible with the existence of population foci at a microgeographic scale, where clonality alternates with sexuality of an endogamic nature, with possible occasional recombination events between individuals of different genotypes. These findings provide key clues on the ecology and transmission patterns of Leishmania parasites. PMID:19497885

Rougeron, Virginie; De Meeûs, Thierry; Hide, Mallorie; Waleckx, Etienne; Bermudez, Herman; Arevalo, Jorge; Llanos-Cuentas, Alejandro; Dujardin, Jean-Claude; De Doncker, Simone; Le Ray, Dominique; Ayala, Francisco J.; Bañuls, Anne-Laure

2009-01-01

217

The expression of HSP83 genes in Leishmania infantum is affected by temperature and by stage-differentiation and is regulated at the levels of mRNA stability and translation  

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Full Text Available Abstract Background Exposure of Leishmania promastigotes to the temperature of their mammalian hosts results in the induction of a typical heat shock response. It has been suggested that heat shock proteins play an important role in parasite survival and differentiation. Results Here we report the studies on the expression of the heat shock protein 83 (HSP83 genes of Leishmania infantum. Confirming previous observations for other Leishmania species, we found that the L. infantum HSP83 transcripts also show a temperature-dependent accumulation that is controlled by a post-transcriptional mechanism involving sequences located in the 3'-untranslated region (3'-UTR. However, contrary to that described for L. amazonensis, the accumulation of the HSP83 transcripts in L. infantum is dependent on active protein synthesis. The translation of HSP83 transcripts is enhanced during heat shock and, as first described in L. amazonensis, we show that the 3'-UTR of the L. infantum HSP83 gene is essential for this translational control. Measurement of the steady-state levels of HSP83 transcripts along the promastigote-to-amastigote differentiation evidenced a specific profile of HSP83 RNAs: after an initial accumulation of HSP83 transcripts observed short after (2 h incubation in the differentiation conditions, the amount of HSP83 RNA decreased to a steady-state level lower than in undifferentiated promastigotes. We show that this transient accumulation is linked to the presence of the 3'-UTR and flanking regions. Again, an 8-fold increase in translation of the HSP83 transcripts is observed short after the initiation of the axenic differentiation, but it is not sustained after 9 h. Conclusions This transient expression of HSP83 genes could be relevant for the differentiation of Leishmania, and the underlying regulatory mechanism may be part of the developmental program of this parasite.

Abanades Daniel R

2004-06-01

218

Síntese, caracterização e estudo da atividade inibitória de novas dialquilfosforilarilidrazonas sobre o crescimento de tripanossomatídeos Synthesis, caracterization and study of activity inhibitory of new dialkylphosphoryl-hydrazones on the growth of trypanosomatids  

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Full Text Available A new series of dialkylphosphorylhydrazones was synthesized through the condensation of aromatic aldehydes with different phosphorylhydrazines. All synthesized compounds were characterized by IR, ¹H-NMR, 13C-NMR and 31P-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.

Andréa Janaina M. Nogueira

2011-01-01

219

Western blot analysis as an aid for the diagnosis of cutaneous leishmaniasis due to Leishmania major.  

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Cutaneous leishmaniasis (CL) due to Leishmania major is endemic in the Old World. To evaluate the diagnostic value of Western blot (WB) compared with IFAT, we tested serum samples from 45 patients with proven CL. Twenty-one (47%) patients were positive by IFAT and all patients were positive by WB with specific bands against 14kDa and/or 18kDa Leishmania antigens. Our results suggest that WB could be a useful non-invasive tool for the diagnosis of CL caused by L. major. PMID:22657532

Pomares, Christelle; Despierres, Laura; del Giudice, Pascal; Delaunay, Pascal; Michel, Grégory; Ferrua, Bernard; Marty, Pierre

2012-07-01

220

Xiphidorus amazonensis n. sp. (Nematoda: Longidoridae) from the Brazilian Amazon Basin.  

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Xiphidorus amazonensis n. sp. was found in the rhizospheres of Jatropha curcas, Musa sp., Anona muricata, Cassia tora, Panicum laxum, Paspalum fasciculatum, Aeschynomene sensitiva, Saccharum officinarum, Manihot esculenta, Abelmoschus esculentus, Tamarindus indica, Mangifera indica, Vigna unguiculata, Zea mays, Commelina sp., Cyperus rotundus, Fimbristylis miliacea, Citrus sinensis, and Eichhornia crassipes on the Amazon River island of Xiborena, approximately 40 km southeast of Manaus, capital of the State of Amazonas. The type habitat is flooded annually for about 6 months by the Amazon River. Xiphidorus amazonensis n. sp. differs from the closely related species Xiphidorus yepesara Monteiro, 1976 by the larger size, by a, b, and c values, and by the rounded tail terminus. It also resembles Xiphidorus tucumanensis Chaves and Coomans, 1984, but can be distinguished by its larger size, larger a, b, and c values, more conical female tail, bilobed amphidial pouch, and the presence of a spermatheca full of sperm. PMID:19294098

Uesugi, C H; Huang, C S; Cares, J E

1985-07-01

221

Distribución geográfica de especies de Leishmania aisladas de pacientes consultantes al Instituto Nacional de Dermatología Federico Lleras Acosta, E.S.E., 1995-2005 / Geographic distribution of Leishmania species isolated from patients at the National Institute of Dermatology Federico Lleras Acosta E.S.E., 1995-2005  

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Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish 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 braziliensis 15,33%; 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. Abstract in english Introduction. The Colombian distribution map of Leishmania species has not been updated since seven years ago. Objective. To describe the distribution of Leishmania species isolated from patients attended at the National Institute of Dermatology during the period 1995 to 2005. Materials and methods. [...] A descriptive study of the geographic distribution of Leishmania species was made from 137 isolates obtained from patients consulting the National Institute of Dermatology "Federico Lleras Acosta E.S.E", with confirmed diagnosis of leishmaniasis. The clinical history was reviewed to obtain information on the clinical presentation, most probable place of infection, age and gender. Samples were taken and cultured and the isolates were typed by monoclonal antibodies, comparing 10% of the results with those obtained by PCR and isoenzymatic patterns. Results. L. panamensis accounted for 74.45% of the 137 isolates studied, L. braziliensis for 15.33%, L. guyanensis for 0.73%; L. mexicana complex for 3.65%, L. mexicana 5.11% and the remaining 0.73% corresponded to an isolate which could not be characterized by monoclonal antibodies. The distribution of L. braziliensis, L. panamensis and L. guyanensis was similar to that reported in previous studies but species of the L. mexicana complex, were found in patients from the departments of Caldas, Santander, Cundinamarca, Caquetá, Casanare, Cauca and Valle del Cauca, where they had not been previously reported. Conclusion. Species of the L. mexicana complex display a wider distribution than previously reported. The usefulness of species-specific monoclonal antibodies, isoenzymatic patterns, and PCR for identification of L. mexicana and L. amazonensis was limited.

Clemencia Elena, Ovalle; Luisa, Porras; Maritza, Rey; Melania, Ríos; Yenny Carolina, Camargo.

2006-10-01

222

First occurrence of an autochthonous canine case of Leishmania (Leishmania infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil Ocorrência do primeiro caso autóctone canino por Leishmania (Leishmania infantum chagasi no Município de Campinas, Estado de São Paulo, Brasil  

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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.Caso autóctone de leishmaniose visceral é relatado em cão (Canis familiaris, aparentemente em área não endêmica. DNA obtido a partir de amostras do baço e fígado foram submetidos a nested-PCR baseada no rDNA específico de Leishmania. Os produtos das PCR foram sequenciados e os 490 pares de base foram idênticos a Leishmania (Leishmania infantum chagasi. Esses resultados são surpreendentes, uma vez que, nenhum caso autóctone canino ou humano de leishmaniose visceral havia sido relatado neste município. Esse caso sugere que a transmissão natural da doença está ocorrendo nesta área.

Elisa San Martin Mouriz Savani

2011-08-01

223

First occurrence of an autochthonous canine case of Leishmania (Leishmania) infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil / Ocorrência do primeiro caso autóctone canino por Leishmania (Leishmania) infantum chagasi no Município de Campinas, Estado de São Paulo, Brasil  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Caso autóctone de leishmaniose visceral é relatado em cão (Canis familiaris), aparentemente em área não endêmica. DNA obtido a partir de amostras do baço e fígado foram submetidos a nested-PCR baseada no rDNA específico de Leishmania. Os produtos das PCR foram sequenciados e os 490 pares de base for [...] am idênticos a Leishmania (Leishmania) infantum chagasi. Esses resultados são surpreendentes, uma vez que, nenhum caso autóctone canino ou humano de leishmaniose visceral havia sido relatado neste município. Esse caso sugere que a transmissão natural da doença está ocorrendo nesta área. Abstract in english 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.

Elisa San Martin Mouriz, Savani; Douglas, Presotto; Thais, Roberto; Maria Cecília Gibrail de Oliveira, Camargo; Sandra Regina Nicoletti, D' auria; Débora Veiga, Sacramento.

2011-08-01

224

An outbreak of american cutaneous leishmaniasis (Leishmania braziliensis braziliensis) in a periurban area of Rio de Janeiro city, Brazil: clinical and epidemiological studies Um surto de leishmaniose cutânea americana (Leishmania braziliensis braziliensis) numa área periurbana da cidade do Rio de Janeiro, Brasil: estudos clínicos e epidemiológicos  

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From July 1984 to September 1986, 105 cases of American cutaneous leishmaniasis were studied in a locality closely situated to an urbanized area of the city of Rio de Janeiro, Brazil. Settement in this area was established at least 20 years ago but the first cases were noted six months prior to the beginning of this study. Cases were almost exlusively cutaneous and ulcerated, with one to six months of evolution. Montenegro's skin tests were positive in all cases and anti-Leishmania antibodies...

Oliveira-neto, Manoel P.; Claude Pirmez; Elizabeth Rangel; Armando Schubach; Gabriel Grimaldi Júnior

1988-01-01

225

Infecção natural de Lutzomyia longipalpis por Leishmania sp. em Teresina, Piauí, Brasil Natural infection of Lutzomyia longipalpis by Leishmania sp. in Teresina, Piauí State, Brazil  

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Full Text Available No Brasil, o controle do vetor Lutzomyia longipalpis é uma das principais estratégias utilizadas para limitar a expansão da leishmaniose visceral americana. Entretanto, poucos são os estudos sobre a infecção natural destes flebotomíneos por espécies de Leishmania. Um estudo sobre a infecção natural de Lu. longipalpis por Leishmania sp. foi realizado no bairro Bela Vista, Teresina, Piauí, um dos principais focos urbanos da leishmaniose visceral americana no Brasil. Entre fevereiro de 2004 e janeiro de 2005 realizaram-se 180 capturas usando-se armadilhas luminosas do tipo CDC. Foram dissecadas e examinadas, em média, dez fêmeas por captura para detecção de formas evolutivas de Leishmania sp., identificando-se 1.832 exemplares de Lu. longipalpis e seis de Lu. whitmani. Vinte (1,1% espécimes, todas de Lu. longipalpis, estavam infectadas com as formas procíclica e nectomonada de Leishmania sp., localizadas, principalmente, na porção posterior do trato digestivo. O maior percentual de insetos infectados foi encontrado quatro meses após o período de maior precipitação pluviométrica, sugerindo que variáveis climáticas podem contribuir para a predição não apenas da abundância destes dípteros, mas também do seu grau de infecção natural.In Brazil, control of the vector Lutzomyia longipalpis is one of the main strategies used to limit the expansion of American visceral leishmaniasis. However, studies on the ecology of this sand fly are rare, especially regarding its natural infection with species of Leishmania. A study of the natural infection of Lu. longipalpis by Leishmania sp. was carried out in the Bela Vista neighborhood in the city of Teresina, Piauí State, Brazil, an important area of American visceral leishmaniasis transmission. From February 2004 to January 2005, sand flies were captured with CDC light traps. Approximately 10 female sand flies in each capture were dissected and examined for the presence of evolutionary forms of Leishmania sp. Two sand fly species were identified: 1,832 were Lu. longipalpis and six Lu. whitmani. Twenty female sand flies (1.1%, all Lu. longipalpis, were infected with procyclic and nectomonad forms of Leishmania sp., found mostly in the hindgut. Higher proportions of infected sand flies were found four months after the rainy season, suggesting that environmental factors may predict not only vector abundance (as already known but also their level of infection.

Jackellyne Geórgia Dutra e Silva

2007-07-01

226

Evaluacion por Western Blot, Inmunofluorescencia Indirecta y ELISA de Perros Infectados con Leishmania (Leishmania) infantum / Western blot, ELISA and indirect immunofluorescence test evaluation of Leishmania (Leishmania) infantum-infected dogs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Objetivo Evaluar el desempeño de las pruebas empleadas en Colombia para el diagnóstico de la leishmaniasis visceral canina y adaptar una técnica de Western blot empleando animales experimental y naturalmente infectados. Metodología Se obtuvieron sueros de 10 perros infectados experimentalmente con L [...] . infantum, 5 perros infectados naturalmente, 16 perros sanos, 26 de reacción cruzada (infectados con Babesia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi, Leishmania (Viannia) spp.), 40 de zonas no endémicas y 150 de zona endémica. Todos fueron evaluados mediante las pruebas de inmunofluorescencia indirecta (IFI), ELISA y Western blot (WB). Resultados Se encontró que IFI tuvo el mayor porcentaje de positividad en los perros infectados (73 %) mientras que el menor porcentaje de falsos positivos se obtuvo por WB (2,5 %). La prueba de ELISA fue la menos eficiente. Fueron reconocidas 24 fracciones antigénicas, las bandas de 29, 34, 50, 69, 75, 86, 99 y 123 kDa fueron responsables de reacciones inespecíficas en los sueros de perros sanos, de zona no endémica y de reacción cruzada. Las bandas por debajo de 29 kDa mostraron ser potencialmente diagnósticas, especialmente la fracción de 13 kDa. Conclusiones Los métodos directos y serológicos pueden subdiagnosticar la infección por Leishmania, solamente un constructo que combine tanto pruebas directas como indirectas sería la forma más eficiente de diagnóstico. Abstract in english Objective Evaluating canine visceral leishmaniasis diagnostic test performance in Colombia and adapting the Western blot test in naturally and experimentally infected dogs. Methods Sera were obtained from 10 experimentally L. Infantum-infected dogs, 5 naturally infected dogs, 16 healthy dogs, 26 Bab [...] esia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi and Leishmania (Viannia) spp infected dogs, 40 dogs from non-endemic areas and 150 from endemic areas. Sera were tested for L. infantum infection using immunofluorescent antibody (IFAT), ELISA and Western blot (WB) tests. Results Positives results were obtained for 73 % of known infected dogs by the IFAT test and false positives were obtained for 2.5 % of non-infected dogs using WB. ELISA was not efficient for diagnosis. 24 antigenic fractions were recognised in tested sera using WB; however, 29, 34, 50, 69, 75, 86, 99 and 123 kDa bands were recognised in sera from dogs from non-endemic areas, healthy dogs and Trypanosoma cruzi, Erhlichia canis, Dirofilaria immitis and Babesia canis infected dogs. The 13 kDa fraction proved potentially useful for diagnosing canine visceral leishmaniasis. ConclusionsThe separate use of parasitological and serological test could lead to misdiagnosis of Leishmania infection; using both kinds of technique simultaneously is thus highly recommended.

Jimmy J, Vargas-Duarte; Myriam C, López-Páez; Jesús E, Escovar-Castro; José, Fernández-Manrique.

2009-08-01

227

Evaluacion por Western Blot, Inmunofluorescencia Indirecta y ELISA de Perros Infectados con Leishmania (Leishmania) infantum / Western blot, ELISA and indirect immunofluorescence test evaluation of Leishmania (Leishmania) infantum-infected dogs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish Objetivo Evaluar el desempeño de las pruebas empleadas en Colombia para el diagnóstico de la leishmaniasis visceral canina y adaptar una técnica de Western blot empleando animales experimental y naturalmente infectados. Metodología Se obtuvieron sueros de 10 perros infectados experimentalmente con L [...] . infantum, 5 perros infectados naturalmente, 16 perros sanos, 26 de reacción cruzada (infectados con Babesia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi, Leishmania (Viannia) spp.), 40 de zonas no endémicas y 150 de zona endémica. Todos fueron evaluados mediante las pruebas de inmunofluorescencia indirecta (IFI), ELISA y Western blot (WB). Resultados Se encontró que IFI tuvo el mayor porcentaje de positividad en los perros infectados (73 %) mientras que el menor porcentaje de falsos positivos se obtuvo por WB (2,5 %). La prueba de ELISA fue la menos eficiente. Fueron reconocidas 24 fracciones antigénicas, las bandas de 29, 34, 50, 69, 75, 86, 99 y 123 kDa fueron responsables de reacciones inespecíficas en los sueros de perros sanos, de zona no endémica y de reacción cruzada. Las bandas por debajo de 29 kDa mostraron ser potencialmente diagnósticas, especialmente la fracción de 13 kDa. Conclusiones Los métodos directos y serológicos pueden subdiagnosticar la infección por Leishmania, solamente un constructo que combine tanto pruebas directas como indirectas sería la forma más eficiente de diagnóstico. Abstract in english Objective Evaluating canine visceral leishmaniasis diagnostic test performance in Colombia and adapting the Western blot test in naturally and experimentally infected dogs. Methods Sera were obtained from 10 experimentally L. Infantum-infected dogs, 5 naturally infected dogs, 16 healthy dogs, 26 Bab [...] esia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi and Leishmania (Viannia) spp infected dogs, 40 dogs from non-endemic areas and 150 from endemic areas. Sera were tested for L. infantum infection using immunofluorescent antibody (IFAT), ELISA and Western blot (WB) tests. Results Positives results were obtained for 73 % of known infected dogs by the IFAT test and false positives were obtained for 2.5 % of non-infected dogs using WB. ELISA was not efficient for diagnosis. 24 antigenic fractions were recognised in tested sera using WB; however, 29, 34, 50, 69, 75, 86, 99 and 123 kDa bands were recognised in sera from dogs from non-endemic areas, healthy dogs and Trypanosoma cruzi, Erhlichia canis, Dirofilaria immitis and Babesia canis infected dogs. The 13 kDa fraction proved potentially useful for diagnosing canine visceral leishmaniasis. ConclusionsThe separate use of parasitological and serological test could lead to misdiagnosis of Leishmania infection; using both kinds of technique simultaneously is thus highly recommended.

Jimmy J, Vargas-Duarte; Myriam C, López-Páez; Jesús E, Escovar-Castro; José, Fernández-Manrique.

2009-08-01

228

Evaluacion por Western Blot, Inmunofluorescencia Indirecta y ELISA de Perros Infectados con Leishmania (Leishmania infantum Western blot, ELISA and indirect immunofluorescence test evaluation of Leishmania (Leishmania infantum-infected dogs  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo Evaluar el desempeño de las pruebas empleadas en Colombia para el diagnóstico de la leishmaniasis visceral canina y adaptar una técnica de Western blot empleando animales experimental y naturalmente infectados. Metodología Se obtuvieron sueros de 10 perros infectados experimentalmente con L. infantum, 5 perros infectados naturalmente, 16 perros sanos, 26 de reacción cruzada (infectados con Babesia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi, Leishmania (Viannia spp., 40 de zonas no endémicas y 150 de zona endémica. Todos fueron evaluados mediante las pruebas de inmunofluorescencia indirecta (IFI, ELISA y Western blot (WB. Resultados Se encontró que IFI tuvo el mayor porcentaje de positividad en los perros infectados (73 % mientras que el menor porcentaje de falsos positivos se obtuvo por WB (2,5 %. La prueba de ELISA fue la menos eficiente. Fueron reconocidas 24 fracciones antigénicas, las bandas de 29, 34, 50, 69, 75, 86, 99 y 123 kDa fueron responsables de reacciones inespecíficas en los sueros de perros sanos, de zona no endémica y de reacción cruzada. Las bandas por debajo de 29 kDa mostraron ser potencialmente diagnósticas, especialmente la fracción de 13 kDa. Conclusiones Los métodos directos y serológicos pueden subdiagnosticar la infección por Leishmania, solamente un constructo que combine tanto pruebas directas como indirectas sería la forma más eficiente de diagnóstico.Objective Evaluating canine visceral leishmaniasis diagnostic test performance in Colombia and adapting the Western blot test in naturally and experimentally infected dogs. Methods Sera were obtained from 10 experimentally L. Infantum-infected dogs, 5 naturally infected dogs, 16 healthy dogs, 26 Babesia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi and Leishmania (Viannia spp infected dogs, 40 dogs from non-endemic areas and 150 from endemic areas. Sera were tested for L. infantum infection using immunofluorescent antibody (IFAT, ELISA and Western blot (WB tests. Results Positives results were obtained for 73 % of known infected dogs by the IFAT test and false positives were obtained for 2.5 % of non-infected dogs using WB. ELISA was not efficient for diagnosis. 24 antigenic fractions were recognised in tested sera using WB; however, 29, 34, 50, 69, 75, 86, 99 and 123 kDa bands were recognised in sera from dogs from non-endemic areas, healthy dogs and Trypanosoma cruzi, Erhlichia canis, Dirofilaria immitis and Babesia canis infected dogs. The 13 kDa fraction proved potentially useful for diagnosing canine visceral leishmaniasis. ConclusionsThe separate use of parasitological and serological test could lead to misdiagnosis of Leishmania infection; using both kinds of technique simultaneously is thus highly recommended.

Jimmy J Vargas-Duarte

2009-08-01

229

MICROBIOLOGY: Mariner Sails into Leishmania  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required: Transposons are bits of DNA that can move from place to place in the genomes of plants and animals. The wide-ranging transposon mariner is found in many different animals, and in this issue Gueiros-Filho and Beverley show that, given the right circumstances, it can also move into the genome of Leishmania, the cause of a deadly disease in the tropics. In his Perspective, Hartl explains the features of this transposable element and how the ability to move it into the Leishmania genome will increase the tools available in the search for a treatment for this pathogen.

Daniel L. Harti (Harvard University; Department of Organismic and Evolutionary Biology)

1997-06-13

230

Observations on the sandfly (Diptera: Psychodidae) fauna of Além Paraíba state of Minas Gerais, Brazil, and the isolation of a parasite of the Leishmania braziliensis complex from Psychodopygus hirsuta hirsuta  

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Dissection of 765 sandflies captured in Além Paraíba (the type locality of Leishmania braziliensis) resulted in the isolation, from Psychodopygus hirsuta hirsuta, of a parasite of the Le. braziliensis complex.Foram dissecados 765 flebótomos capturados em Além Paraíba (localidade tipo da Leishmania braziliensis) resultando no isolamento de um parasita do complexo Le. braziliensis, encontrado em Psychodopygus hirsuta hirsuta naturalmente infectado.

Rangel, Elizabeth F.; Lee Ryan; Ralph Lainson; Shaw, Jeffrey J.

1985-01-01

231

Evolution and species discrimination according to the Leishmania heat-shock protein 20 gene.  

Science.gov (United States)

The Leishmania genus comprises up to 35 species, of which 20 are responsible for human disease. However, the taxonomic status for many of them is under discussion. The small Heat Shock Proteins (sHSPs) are physiologically relevant, protecting cellular proteins from aggregation and maintaining cellular viability under intensive stress conditions. In Leishmania, a protein of this class was previously described, the 20-kDa heat-shock protein (HSP20), which is encoded by a single gene. In the present study, we used this target, alone or in combination with hsp70 gene, to investigate the phylogenetic relationships among Leishmania species. Using a pair of degenerate primers it was possible amplifying a 370bp fragment of the hsp20 coding region in 39 strains of very different geographic origins, representing in total 16 Leishmania species (14 if L. chagasi and L. archibaldi are considered synonymous names of L. infantum and L. donovani, respectively). Nucleotide sequences were readily obtained by direct sequencing of the amplification products. Both phylogenetic trees and networks based on either hsp20 sequences or combined datasets of hsp20 and hsp70 sequences were constructed. These phylogenic analyses supported the division of the Leishmania genus into nine species: L. (L.) donovani, L. (L.) major, L. (L.) tropica, L. (L.) aethiopica, L. (L.) mexicana, L. (V.) lainsoni, L. (V.) naiffi, L. (V.) guyanensis and L. (V.) braziliensis. Additionally, by network analysis, the subspecies L. (L.) donovani infantum and L. (V.) braziliensis peruviana were recognized within the L. (L.) donovani and L. (V.) braziliensis species, respectively. Therefore, hsp20 gene was found to be a suitable molecular marker for Leishmania typing and classification purposes. In addition, this study represents a solid contribution to the objective of establishing a more reliable taxonomy for the genus Leishmania. PMID:23722022

Fraga, Jorge; Montalvo, Ana Margarita; Van der Auwera, Gert; Maes, Ilse; Dujardin, Jean-Claude; Requena, José M

2013-08-01

232

Aspectos ecológicos da leishmaniose tegumentar americana: 8. avaliação da atividade enzoótica de Leishmania (Viannia) braziliensis, em ambiente florestal e peridomiciliar, região do Vale do Ribeira, Estado de São Paulo, Brasil / Ecological aspects of American cutaneous leishmaniasis: 8. assessment on enzootic activity of Leishmania (V.) braziliensis, in forest and peridomicile environments of the Ribeira Valley region, São Paulo State, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A evidência da transmissão extraflorestal da leishmaniose cutâneo-mucosa na região do Vale do Ribeira ensejou o presente estudo epidemiológico prospectivo, visando avaliar a atividade enzoótica de L. (V.) braziliensis. A pesquisa paratisológica da infecção natural em pequenos mamíferos e população c [...] anina foi complementada com o teste de imunofluorescência indireta (IFI) para cães e captura de flebotomíneos em ambiente florestal e peridomiciliar. A positividade para o teste sorológico e exame parasitológico somente foi observada para cães residentes e com taxas de 5,6 e 2,4%, respectivamente. Entre animais silvestres e sinantrópicos capturados, destacam-se os pertencentes a Oryzomys (Oligoryzomys) e Rattus rattus, ambos assinalados em proporções equivalentes (29,3%), em ambiente peridomiciliar. Foram capturados apenas 166 exemplares femininos de Lutzomyia intermedia, fato atribuído à borrifação das habitações humanas e anexos com DDT. No contexto epidemiológico mais amplo, discute-se a fragilidade do ciclo extraflorestal da L. (V.) braziliensis; o papel do cão e de pequenos mamíferos, como fonte de infecção domiciliar, além de analisar o potencial deles na dispersão do parasita na área estudada. Abstract in english The evidence of mucocutaneous leishmaniasis transmission in the non-forest environment in the Ribeira Valley region, São Paulo, Brazil, has made this epidemiologic four years' study possible, viewing the enzootic activity of L. (V.) braziliensis. Furthermore, the natural infection in small mammals a [...] nd the domestic dog population has been completed in collecting of phlebotomine sandflies in the forest and peridomiciliar environments. Positive test-results have only been found in resident dogs (Canis familiaris) with a rate of 5.6 and 2.4% for serological and parasitological test respectively. Among silvatic and synanthropic rodents collected, Oryzomys (Olygoryzomys) and Rattus rattus are preeminent having both been collected in equal proportions, in peridomiciliar environment. The sandfly Lutzomyia intermedia has contributed only with 166 feminine specimens due to insecticide (DDT) application on and in the human and domestic habitations. From the general epidemiologic standpoint the fragile L. (V.) braziliensis cycle in the unforested areas as well as the canine and small mammals roles as a domiciliar infection source are discussed, and their potencial in the dispersion of this parasite in the researched area is analysed too.

Almério de Castro, Gomes; Sergio Gomes, Coutinho; Gil Vianna, Paim; Sandra Maria Otatti de, Oliveira; Eunice Aparecida Bianchi, Galati; Marise Pinheiro, Nunes; Antonio Norberto, Capinzaiki; Yoshimi Imoto, Yamamoto; Paul, Rotter.

1990-04-01

233

Fatty acid and hydrocarbon composition in tropical marine Shewanella amazonensis strain SB2B(T).  

Science.gov (United States)

Shewanella amazonensis strain SB2B(T) is an isolate from shallow-water marine sediments derived from the Amazon River delta. This bacterium contained a long-chain polyunsaturated hydrocarbon, all-cis -3,6,9,12,16,19,22,25,28 hentriacontanonaene (C31:9), constituting 1-2% of the total fatty acid methyl ester and hydrocarbon fraction, which was produced dependently of decreased growth temperature. Analysis of its cellular fatty acid composition demonstrated that isopentadecanoic acid was the major fatty acid component and that all the main monounsaturated fatty acids had straight chains with a cis configuration. However, monoenoic cyclopropyl fatty acids, which were previously reported to be present in this bacterium, were not detected by mass spectrometric analysis. The growth temperature affected the content of ?9-cis -hexadecenoic [16:1(?9c)], palmitic, and heptadecanoic acids. These results suggest that C31:9, as well as 16:1(?9c) might be involved in adaptation to low temperature in S. amazonensis strain SB2B(T) . Our result suggests that polyunsaturated fatty acid synthase protein complex may be involved in synthesis of C31:9 but not in production of eicosapentaenoic acid. PMID:21656813

Motoigi, Taro; Okuyama, Hidetoshi

2011-10-01

234

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 Imunofluorescê [...] ncia 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. Abstract in english 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 Ind [...] irect 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 low. Such low incidence suggests that these hosts has no epidemiological relevance in the study area.

Katia Denise Saraiva, Bresciani; Ana Claudia Marques, Serrano; Lucas Vinicius Shigaki de, Matos; Elisa San Martin Mouriz, Savani; Sandra Regina Nicoletti, D' Auria; Silvia Helena Venturoli, Perri; Fabio Luiz, Bonello; Willian Marinho Dourado, Coelho; Carolina Godoi, Aoki; Alvimar José da, Costa.

2010-06-01

235

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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, visi [...] bilizaram-se formas amastigotas compatíveis com Leishmania sp. Abstract in english 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 resembli [...] ng Leishmania sp. were visualized by citology.

F.L.C., Brito; L.C., Alves; F.C.L., Maia; A.R., Albuquerque; J.P.D., Ortiz; J.L., Laus.

2007-02-01

236

Characterization of a Monoclonal Antibody Specific for the Parasite Surface Antigen-2 of Leishmania major  

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Full Text Available The Leishmania major Parasite surface Antigen-2 (PSA-2 is a family of glycoinositol phospholipids anchored glycoprotoins expressed in both promastigotes and amastigotes. Promastigote PSA-2 comprises three polypeptides with approximate molecular weight of 96, 80 and 50 kDa. Amastigote express a distinct but closely PSA-2 polypeptide with molecular weight of 50 kDa. In this study fusion of SP2/0 myeloma cells with immunized mice spleenocytes infected with promastigotes of L. major intraperitoneally resulted to a clone of hybridoma producing a specific antibody that only reacts with L. major parasite surface antigen (PSA-2. This mAb showed no crossreactivity with either other Leishmania species including L. tropica, L. donovani and L. infantum or recombinant gp63. Western blot analysis of culture supernatant revealed multiple bands with molecular weight of 50, 58, 80 and 96 kDa only in L. major.

"AR Khabiri

2004-08-01

237

Design of inhibitors for nucleoside hydrolase from Leishmania donovani using molecular dynamics studies  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste trabalho é proposto o primeiro modelo por homologia para a nucleosídeo hidrolase de Leishmania donovani construído a partir das estruturas das nucleosídeo hidrolases de Crithidia fasciculata e de Leishmania major. Usando as informações de interação entre o inibidor p-aminofeniliminoribitol e a [...] nucleosídeo hidrolase de Crithidia fasciculata foram planejados dois novos potenciais inibidores, os quais apresentam novas interações com alguns resíduos da bolsa hidrofóbica do sítio ativo do modelo. Simulações por dinâmica molecular dos protótipos ancorados nos sítios ativos do modelo e das enzimas usadas como moldes, mostraram que, diferente do p-aminofeniliminoribitol, eles permaneceram ancorados nos sítios ativos das três enzimas ao longo de toda a dinâmica, interagindo fortemente com os aminoácidos da bolsa hidrofóbica. Abstract in english In this work we propose the first homology model for nucleoside hydrolase from Leishmania donovani, built based on the crystallographic structures of Crithidia fasciculata and Leishmania major nucleoside hydrolases. We used the interaction information from the crystallographic model of the enzyme of [...] C. fasciculata in complex with the inhibitor p-aminophenyliminoribitol, to design two new potential inhibitors, which present new interactions with some residues of the hydrophobic pocket of the model active site. Molecular dynamics simulations of the prototypes inside the active sites of the model and the template enzymes showed that, differently from p-aminophenyliminoribitol, they remained tightly bound inside the active sites, interacting strongly with the amino acids from the hydrophobic pocket.

Tanos C. C., França; Maria do Ramo M., Rocha; Bruno M., Reboredo; Magdalena N., Rennó; Luzineide W., Tinoco; José D., Figueroa-Villar.

238

Identificación de una secuencia de ADN genómico de Leishmania especifica del subgénero Leishmania / Identification of a genomic DNA sequence of Leishmania, specific of Leishmania subgenus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Leishmania es el agente causante de la compleja enfermedad conocida como leishmaniasis. Las distintas especies de este parásito protozoario se encuentran agrupadas en dos subgéneros, Viannia y Leishmania, de acuerdo a su desarrollo en el mosquito vector. Un ensayo de PCR, ?500-PCR, específico del su [...] bgénero Viannia, ha sido desarrollado utilizando la secuencia de ADN genómico denominada ?500. En este trabajo se presenta el aislamiento e identificación de una secuencia genómica de 280 pb, L280, a partir del ADN genómico de Leishmania (Leishmania) mexicana luego de aplicar el ensayo ?500-PCR en condiciones de baja rigurosidad. La secuenciación parcial de L280 permitió diseñar un ensayo de PCR (L280-PCR) que generó un producto de amplificación de 260 pb, en distintas condiciones de rigurosidad, cuando se utilizó el ADN genómico de distintas especies pertenecientes al subgénero Leishmania. El ensayo L280-PCR resultó negativo para el ADN genómico de distintas especies del subgénero Viannia al igual que para el ADN de otros organismos kinetoplastidos o humano. Los resultados sugieren que el ensayo L280-PCR es específico del subgénero Leishmania. Abstract in english Leishmania is the causal agent of the leishmaniasis disease. The different species of this protozoa parasite are grouped in two subgenera, Viannia and Leishmania, according to their development in the sandfly vector. A specific PCR assay, ?500-PCR, has been developed for the Viannia subgenus using t [...] he genomic ?500 DNA sequence. In the present work we present the isolation and identification of a genomic sequence of 280 bp, L280, obtained from genomic DNA of Leishmania (Leishmania) mexicana after application of the ?500-PCR assay at low stringency. After partial sequencing of L280 a PCR assay was generated, L280-PCR, this yielded a product of 260 bp at different conditions of stringency, when genomic DNA of different species of Leishmania subgenus was used. The L280-PCR assay was negative to genomic DNA of species belonging to the Viannia subgenus and also to other kinetoplastid organisms and human. The results suggest specificity of the L280-PCR assay for the Leishmania subgenus.

Andrea, Orué; Nancy Y, De Abreu; Clara, Martínez; Alexis, Mendoza-León.

2008-06-01

239

Infecção por Leishmania (Leishmania chagasi em crianças de uma área endêmica de leishmaniose visceral americana na Ilha de São Luis-MA, Brasil  

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Full Text Available Realizou-se estudo prospectivo com 648 crianças de zero a cinco anos no município da Raposa-MA, de julho/97 a junho/98, com o objetivo de avaliar as características da infecção por L.(L.chagasi e verificar se existe associação entre desnutrição e infecção assintomática. Utilizou-se questionário com dados socioeconômicos, ambientais e hábitos de vida; realizou-se Intradermorreação de Montenegro(IDRM com antígeno de L. amazonensis e Enzyme Linked Immunosorbant Assay(ELISA para detectar infecção, e exame antropométrico. A prevalência inicial, final e incidência da infecção foram 18,6%, 20,6% e 10,8% pelo IDRM, e 13,5%, 34,4% e 28% pelo ELISA, respectivamente. A prevalência da desnutrição crônica (altura/idade foi 26%. Não houve associação estatisticamente significante entre desnutrição e infecção assintomática por L. (L. chagasi. A forma assintomática da doença está presente nas áreas estudadas, necessitando de medidas de controle mais efetivas.

Caldas Arlene J.M.

2001-01-01

240

Susceptibility of laboratory-reared female Lutzomyia longipalpis (Lutz & Neiva, 1912) to infection by different species and strains of Leishmania Ross, 1903  

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Full Text Available A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all ( [...] 18/18) of the specimens examined. A lower infection rate of 37 per cents (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13 per cents (6/46) of the sand flies that glood fed on dogs in the earlly stage of experimental infection with an old laboratory strain of Le. chagasi. In contrast, promastigotes did not develop in sand flies that blood fed on dogs with naturally acquired Le. chagasi. The naturally infected dogas were in an advanced stage of disease. Flagellates developed in 9// (3/32) of the sand flies that blood fed on lesions of hamsters infected with a strain of Le. braziliensis and in 9 per cents (3/34) of those that fed on hamsters with lesions due to a parasite fo the mexicana complex (strain MHOM/BR/73/BH121). Sand flies did not develop flagellate infections after blood feeding on hamsters bearing lesions induced by strain MHOM/BR/71/BR49. Factors influencing the susceptibility of Lu. longipalpis to infection by New World species of Leishmania are discussed.

Ana Lúcia F. F. da, Silva; Paul, Williams; Maria Norma, Melo; Wilson, Mayrink.

1990-12-01

241

Paromomycin: uptake and resistance in Leishmania donovani  

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Paromomycin is currently in phase IV clinical trials against leishmaniasis. In the present work we elucidate the effect and mechanism of uptake of paromomycin in Leishmania donovani. The in vitro sensitivities of both promastigotes and amastigotes were determined to this aminoglycoside. Association of paromomycin with Leishmania donovani involved a rapid initial phase that was non-saturable up to 1 mM of the drug. This initial phase was largely independent of temperature and not affected by m...

Jhingran, Anupam; Chawla, Bhavna; Saxena, Shailendra; Barrett, Michael Peter; Madhubala, Rentala

2008-01-01

242

Leishmania donovani Develops Resistance to Drug Combinations  

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Drug combinations for the treatment of leishmaniasis represent a promising and challenging chemotherapeutic strategy that has recently been implemented in different endemic areas. However, the vast majority of studies undertaken to date have ignored the potential risk that Leishmania parasites could develop resistance to the different drugs used in such combinations. As a result, this study was designed to elucidate the ability of Leishmania donovani to develop experimental resistance to anti...

Garci?a-herna?ndez, R.; Manzano, J. I.; Castanys, S.; Gamarro, F.

2012-01-01

243

Recombinant Cysteine Proteinase from Leishmania (Leishmania) chagasi Implicated in Human and Dog T-Cell Responses  

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High in vitro lymphoproliferative responses were induced in humans and dogs by a recombinant Leishmania (Leishmania) chagasi cysteine proteinase, with secretion of IFN-? in asymptomatic subjects or of IFN-?, interleukin 4 (IL-4), and IL-10 in oligosymptomatic subjects. In contrast, responses of symptomatic patients and dogs were lower, with production of IL-4 and IL-10.

Da Costa Pinheiro, Paulo Henrique; Souza Dias, Suzana; Eula?lio, Kelsen Dantas; Mendonc?a, Ivete L.; Katz, Simone; Barbie?ri, Clara Lu?cia

2005-01-01

244

Leishmanicidal, antibacterial, and antioxidant activities of Caryocar brasiliense Cambess leaves hydroethanolic extract Atividades leishmanicida, bactericida e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense Cambess  

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Full Text Available The antimicrobial and antioxidant activities of the hydroethanolic extract from Caryocar brasiliense leaves were evaluated. The extract showed leishmanicidal effect against Leishmania amazonensis promastigote forms and bactericidal activity against some pathogenic bacteria. The extract also showed relevant antioxidant activity, similar to that of vitamin C and rutin.As atividades antimicrobiana e antioxidante do extrato hidroetanólico das folhas de Caryocar brasiliense foram estudadas. O extrato demonstrou efeito leishmanicida sobre formas promastigotas de Leishmania amazonensis e atividade bactericida sobre estirpes de bactérias patogênicas para o homem. Além disso, o extrato demonstrou relevante capacidade antioxidante, similar às atividades da vitamina C e da rutina.

Waldemar de Paula-Ju

2006-12-01

245

Host factors influencing outcome of Leishmania mexicana infection in mice  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Estudando a influência de alguns parâmetros relacionados ocm o hospedeiro no curso da infecção com Leishmania mexicana mexicana em camundongos singênicos C57B1/10 (C57) e não singênicos albinos (OA) demonstramos o papel importante das variáveis enumeradas a seguir: Cepa do hospedeiro: o desenvolvime [...] nto e tamanho das lesões variaram significativamente menos nos camundongos C57 do que nos OA. Idade do hospedeiro: inóculos subcutâneos de 2 x 10 [elevado a 4] a 2 x 10 [elevado a 6] amastigotas no dorso da pata trasiera produziram lesões significativamente maiores e que regrediram mais lentamente nos camundongos C57 de 2 meses de idade do que nos de 4 meses. Enquanto uma redução da capacidade de curar lesões foi também observada nas fêmeas C57 mais idosas (8 meses), uma mortalidade baixa ocorreu nos animais infectados de 15 meses de idade, de ambos os sexos. Local da lesão: as lesões de pata de C57 infectados com amastigotas regrediram entre 15 a 25 semanas, mas os da região perinasal, produzidas nesses animais com idêntico inóculo parasitário, foram persistente e progressivos, formando nódulos irregulares. Nos animais infectados simultaneamente em ambas as regiões, cada uma das lesões apresentou uma evolução semelhante àquela observada nos animais da mesma idade infectados em uma das regiões isoladamente, demonstrando que as involuções do processo nesses locais são fenômenos independentes. Assim, esses resultados indicam que enquanto a cepa do hospedeiro pode influir grandemente no curso da infecção, tais variávei como o sítio da lesão e a idade do animal também desempenham papéis importantes, podendo explicar, pelo menos em parte, a variabilidade nas respostas do hospediero face à infecção com uma determinada Leishmania. Abstract in english Studies were undertaken to determine the influence of several host-related parameters on the course of Leishmania mexicana mexicana infection in inbred C57B1/10 (C57) and outbred albino (OA) mice. An important influence of the following variables was demonstrated: Host strain: lesions in C57s were s [...] ignificantly less variable in size and outcome than those of OAs under the conditions studied and even when persistent developed at a slower rate. Host age: Subcutanous injection of 2 x 10 [raised to the power of 4] to 2 x 10 [raised to the power of 6] amastigotes into the dorsum of the rear paw produced significantly larger lesions which healed more slowly in 2 mo. old C57s than in 4 mo. old mice. Reduced healing ability was observed in older (8 mo. old) female C57s, and low mortality occurred after 15 months of age in infected mice of both sexes. Lesion site: Following amastigote infection, lesions in paws of most C57s regress within 15 - 25 wks. In contrast, perinasal legions produced with the same number of parasites tend to persist for the life of the animal as slowly spreading irregular nodules. In animals infected in both locations, each lesion site behaves similarly to that in singly infected animals of the same age, i.e. regression in the two sites is independent. Our results indicate that while host strain may strongly influence infection outcoem, such variables as lesion site and host age play important roles and may explain, in part, reported inter- and intraexperimental variability in responses of murine hosts to a given leishmanial parasite.

Pamela Lane, Moriearty; Gabriel, Grimaldi Junior.

1983-03-01

246

Host factors influencing outcome of Leishmania mexicana infection in mice  

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Full Text Available Studies were undertaken to determine the influence of several host-related parameters on the course of Leishmania mexicana mexicana infection in inbred C57B1/10 (C57 and outbred albino (OA mice. An important influence of the following variables was demonstrated: Host strain: lesions in C57s were significantly less variable in size and outcome than those of OAs under the conditions studied and even when persistent developed at a slower rate. Host age: Subcutanous injection of 2 x 10 [raised to the power of 4] to 2 x 10 [raised to the power of 6] amastigotes into the dorsum of the rear paw produced significantly larger lesions which healed more slowly in 2 mo. old C57s than in 4 mo. old mice. Reduced healing ability was observed in older (8 mo. old female C57s, and low mortality occurred after 15 months of age in infected mice of both sexes. Lesion site: Following amastigote infection, lesions in paws of most C57s regress within 15 - 25 wks. In contrast, perinasal legions produced with the same number of parasites tend to persist for the life of the animal as slowly spreading irregular nodules. In animals infected in both locations, each lesion site behaves similarly to that in singly infected animals of the same age, i.e. regression in the two sites is independent. Our results indicate that while host strain may strongly influence infection outcoem, such variables as lesion site and host age play important roles and may explain, in part, reported inter- and intraexperimental variability in responses of murine hosts to a given leishmanial parasite.Estudando a influência de alguns parâmetros relacionados ocm o hospedeiro no curso da infecção com Leishmania mexicana mexicana em camundongos singênicos C57B1/10 (C57 e não singênicos albinos (OA demonstramos o papel importante das variáveis enumeradas a seguir: Cepa do hospedeiro: o desenvolvimento e tamanho das lesões variaram significativamente menos nos camundongos C57 do que nos OA. Idade do hospedeiro: inóculos subcutâneos de 2 x 10 [elevado a 4] a 2 x 10 [elevado a 6] amastigotas no dorso da pata trasiera produziram lesões significativamente maiores e que regrediram mais lentamente nos camundongos C57 de 2 meses de idade do que nos de 4 meses. Enquanto uma redução da capacidade de curar lesões foi também observada nas fêmeas C57 mais idosas (8 meses, uma mortalidade baixa ocorreu nos animais infectados de 15 meses de idade, de ambos os sexos. Local da lesão: as lesões de pata de C57 infectados com amastigotas regrediram entre 15 a 25 semanas, mas os da região perinasal, produzidas nesses animais com idêntico inóculo parasitário, foram persistente e progressivos, formando nódulos irregulares. Nos animais infectados simultaneamente em ambas as regiões, cada uma das lesões apresentou uma evolução semelhante àquela observada nos animais da mesma idade infectados em uma das regiões isoladamente, demonstrando que as involuções do processo nesses locais são fenômenos independentes. Assim, esses resultados indicam que enquanto a cepa do hospedeiro pode influir grandemente no curso da infecção, tais variávei como o sítio da lesão e a idade do animal também desempenham papéis importantes, podendo explicar, pelo menos em parte, a variabilidade nas respostas do hospediero face à infecção com uma determinada Leishmania.

Pamela Lane Moriearty

1983-03-01

247

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

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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 relat...

Yoshida, Elizaide L. A.; Cuba Cuba, Cesar A.; Raquel da Silva Pacheco; Elisa Cupolillo; Celso Cruz Tavares; Machado, Gerzia M. C.; Hooman Momen; Gabriel Grimaldi Junior

1993-01-01

248

In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis  

Science.gov (United States)

PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-? in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-?, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-? in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-? after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-?-producing CD4+ T cells and the released IFN-?. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection. PMID:24786587

Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria; Pagniez, Julie; Papierok, Gérard-Marie; Rhouma, Faten Bel Haj; Torres, Pilar; Lemesre, Jean-Loup; Chenik, Mehdi; Meddeb-Garnaoui, Amel

2014-01-01

249

Susceptibility of spiny rats (Proechimys semispinosus to Leishmania (Viannia panamensis and Leishmania (Leishmania chagasi  

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Full Text Available The role of Proechimys semispinosus as reservoir of Leishmania (Viannia panamensis on the Colombian Pacific coast was experimentally evaluated. The susceptibility to L. chagasi also was assessed to determine the utility of this rodent as a model for studying reservoir characteristics in the laboratory. Wild-caught animals were screened for natural trypanosomatid infections, and negative individuals were inoculated intradermally (ID in the snout or feet with 10(7 promastigotes of L. panamensis. L. chagasi was inoculated intracardially (10(7 promastigotes or ID in the ear (10(8 promastigotes. PCR-hybridization showed that 15% of 33 spiny rats were naturally infected with L. Viannia sp. Animals experimentally infected with L. panamensis developed non-ulcerated lesions that disappeared by the 7th week post-infection (p.i. and became more resistant upon reinfection. Infectivity to sand flies was low (1/20-1/48 infected/fed flies and transient, and both culture and PCR-hybridization showed that L. panamensis was cleared by the 13th week p.i. Animals inoculated with L. chagasi became subclinically infected and were non-infective to sand flies. Transient infectivity to vectors of spiny rats infected with L. panamensis, combined with population characteristics, e.g., abundance, exploitation of degraded habitats and high reproductive rates, could make them epidemiologically suitable reservoirs.

BL Travi

2002-09-01

250

Histopathological findings and detection of parasites in the eyes of dogs infected naturally with Leishmania chagasi Achados histopatológicos e detecção de parasitas nos olhos de cães infectados por Leishmania chagasi  

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Full Text Available The objective of the present study was to investigate the histopathological alterations and detection of parasites that occur in the eyes of dogs naturally infected with Leishmania chagasi. The eyes of 25 dogs with a positive parasitological and serological exam for L. chagasi were submitted to routine ophthalmic examination. Fragments were obtained from the eyeball and were analyzed by immunohistochemistry and histopathology. Among the structures studied, the conjunctiva of the third eyelid was the tissue most frequently stained for L. chagasi. Histopathological analysis revealed a predominantly mononuclear inflammatory infiltrate whose intensity ranged from discrete to intense in the various ocular structures. Vascular congestion and perivasculitis were also observed. The histopathological alterations that occur in the eyeball of dogs with visceral leishmaniasis might be related to the presence of antibodies.O objetivo deste trabalho foi estudar as alterações histopatológicas e a detecção do parasito nos olhos de cães naturalmente infectados por Leishmania chagasi. Utilizaram-se os olhos de 25 cães com exame parasitológico e sorológico positivo para Leishmania chagasi. Os animais foram submetidos à semiotécnica oftálmica rotineira. Fragmentos do globo ocular foram coletados e destinados à imunoistoquímica e histopatologia. Entre as estruturas avaliadas, a conjuntiva da terceira pálpebra foi a que mais demonstrou imunomarcação da Leishmania chagasi. Na avaliação histopatológica, foi observado predominantemente infiltrado inflamatório mononuclear, variando de discreto a intenso nas diversas estruturas oculares. Congestão vascular e perivasculite também foram observadas. As alterações histopatológicas do bulbo do olho em cães com leishmaniose visceral podem estar relacionadas à presença do anticorpo.

Fábio Luiz da Cunha Brito

2010-05-01

251

Role of Leishmania (Leishmania chagasi amastigote cysteine protease in intracellular parasite survival: studies by gene disruption and antisense mRNA inhibition  

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Full Text Available Abstract Background The parasitic protozoa belonging to Leishmania (L. donovani complex possess abundant, developmentally regulated cathepsin L-like cysteine proteases. Previously, we have reported the isolation of cysteine protease gene, Ldccys2 from Leishmania (L. chagasi. Here, we have further characterized this cysteine protease gene and demonstrated its role during infection and survival of Leishmania (L. chagasi within the U937 macrophage cells. Results The amastigote specific Ldccys2 genes of L. (L. chagasi and L. (L. donovani have identical gene organization, as determined by southern blots. In vivo expression analyses by Northern blots showed that Ldccys2 is amastigote specific. Western blot using anti-Ldccys2 antibody confirmed the amastigote specific protein expression. Recombinant expression of Ldccys2, a 30 kDA protein, was functionally active in a gelatin assay. Results from Ldccys2 heterozygous knockout mutants showed its role during macrophage infection and in intra-macrophage survival of the parasites. Since attempts to generate null mutants failed, we used antisense RNA inhibition to regulate Ldcccys2 gene expression. Not surprisingly, the results from antisense studies further confirmed the results from heterozygous knockout mutants, reiterating the importance of amastigote specific cysteine proteases in Leishmania infection and pathogenesis. Conclusions The study shows that Ldccys2 is a developmentally regulated gene and that Ldccys2 is expressed only in infectious amastigote stages of the parasite. The collective results from both the heterozygous knockout mutants and antisense mRNA inhibition studies shows that Ldccys2 helps in infection and survival of L. (L. chagasi amastigotes within the macrophage cells. Finally, antisense RNA technique can be used as an alternate approach to gene knockout, for silencing gene expression in L. (L. chagasi, especially in cases such as this, where a null mutant cannot be achieved by homologous recombination.

Kucknoor Ashwini S

2005-02-01

252

Síntese, caracterização e estudo da atividade inibitória de novas dialquilfosforilarilidrazonas sobre o crescimento de tripanossomatídeos / Synthesis, caracterization and study of activity inhibitory of new dialkylphosphoryl-hydrazones on the growth of trypanosomatids  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english A new series of dialkylphosphorylhydrazones was synthesized through the condensation of aromatic aldehydes with different phosphorylhydrazines. All synthesized compounds were characterized by IR, ¹H-NMR, 13C-NMR and 31P-NMR spectroscopies. The in vitro investigation of the activity of these compound [...] s 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.

Andréa Janaina M., Nogueira; Marco Edilson F. de, Lima; João Batista N., DaCosta; Eliomara Sousa Sobral, Alves; Danielle Oliveira dos, Anjos; Marcos André, Vannier-Santos; Adriana, Lanfredi-Rangel.

1365-13-01

253

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)

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)

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

254

Efeito leishmanicida in vitro de Stachytarpheta cayennensis (Rich. Vahl (Verbenaceae In vitro leishmanicidal effect of Stachytarpheta cayennensis (Rich. Vahl (Verbenaceae  

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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.Leishmanicidal activity of the hydroalcoholic extract of Stachytarpheta cayennensis, species that is usually employed in ulcers caused by Leishmania, was evaluated in vitro using Leishmania braziliensis and L. amazonensis promastigotes forms. The hydroalcoholic extract was prepared from dried leaves and used in L. amazonensis and L. braziliensis promastigotes cultures at concentrations of 500 to 32.5 µg/mL. After 24 hours the promastigotes forms were quantified and the IC50 was calculated. The cytotoxicity of the extract was evaluated using peritoneal macrophages. The extract presented a dose and specie-dependent leishmanicidal effect to Leishmania promastigotes, mainly to the L. braziliensis ones. The cytotoxic effect was not observed in macrophage cultures. In conclusion, the hydroalcoholic extract of S. cayennensis inhibits the growing of Leishmania promastigotes forms in vitro accounting for the folk use of this vegetal in skin ulcers caused by Leishmania.

Rosilene C.R. Moreira

2007-03-01

255

Leishmania mexicana: chemistry and biochemistry of sodium stibogluconate (Pentostam)  

International Nuclear Information System (INIS)

The chemical properties of the primary antileishmanial agent sodium stibogluconate (Pentostam), and the interaction of Pentostam with Leishmania mexicana amastigotes, have been investigated with the aid of [125Sb]Pentostam. The molecular weight by P2 chromatography showed [125Sb]Pentostam to be of multiple species of MW = 100-4000 Da, rather than the one species of 746 Da predicted by the commonly hypothesized structural formula. Nonradioactive Pentostam had a lower osmolarity (789 mOsm for a 100 mg Sb/ml solution) than predicted (1644 mOsm), which indicates that the multiple components of Pentostam (Sb and derivatives of gluconic acid) are more closely complexed with each other than previously thought. When incubated with L. mexicana amastigotes, labeled drug was bound to at least six polypeptides of molecular weights ranging from 14,000 to 68,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Interaction with the polypeptides is presumed to contribute to the antileishmanial action of Pentostam

256

A soro-aglutinação das Leishmanias Agglutination of Leishmanias  

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Full Text Available The first agglutination experiments (Tables 1 and 2 showed that the serum obtained with any one strain of Leishmania, agglutinates all the others even of another species. This finding reveals the existence of a common antigen. However as the titre of agglutination did not permit a sharp differentiation of species we tried the adsorption method. The first adsorption tests made demonstrated differences in antigenic constitution between a strain of. L. donovani on one hand and strains of L. tropica or L. brasiliensis on the other. Further experiments in which L. chagasi was tested against the other species revealed that the former was antigenically different from the others. These tests were performed by adsorbing an anti-chagasi serum with organisms belonging to the other species or, conversely, adsorbing with L. chagasi sera prepared against the other species (See Tables 9 to 24. On the other hand, the adsorption of a serum prepared against one strain of l. chagasi by another of the same species showed that they had identifical antigenie constitution. These findings suggested the possibility of separating different species of Leishmania by this method. However, tests to separate the other species from one to another gave inconclusive results. (See Tables 27 to 35. It was soon observed that all the strains of L. chagasi were of recent isolation while all the others had been maintained in artificial culture media for a long time. We were led to believe that this condition was responsible for the differences in behaviour encountered. Accordingly, recently isolated strains of L. brasiliensis and L. donovani were tested and shown to be antigenically similar to strains of L. chagasi also recently isolated. The conclusion may be drawn that all strains have the same antigenic constitution when freshly isolated. It has been noted that when a serum which has been prepared against a freshly isolated is adsorbed with an old strain, the amount of agglutinins left free, is much smaller than when a serum prepared against an old strain is adsorbed with a newly isolated strain. At first, we thought to explain this by the low titre of the serum. However, the amount of agglutinins left free was not larger when higher titre serum was tested. The results do not corroborate the view of a special antigen being present in recently isolated strains (vi antige but rather that the phenomenon is dependent on differences of the amount of the common antigen, more abundant in recent strains. In order to make this clear, experiments were made in which equal amounts of a serum prepared against a newly isolated strain were adsorbed by equal amounts, by weight, of, on one hand, a new strain, and the other an old strain. The resulting adsorbed sera were then titrated. (Table 44. Results showed that newly isolated strains adsorb a larger amount of agglutinins (Tables 44, 45. Two hypothesis have bem advanced to explain the stronger adsorbing qualities of the newly isolated strains. 1° - these strains possess larger amounts of the common antigen and 2° - they contain a vi antigen which adsorbed by the new strain together with the common antigen is the cause of their larger adsorbing capacity. To find out which of the two hypothesis corresponds to the reality a new experiment was made, similar to the one summarized in table 44. The adsorbed sera were made to act on a recently isolated strain as well as on an old one. The latter, not containing the vi antigen, the difference seen when sera act on new strains should not be observed here in the case of this antigen being responsible for the differences in adsorbing properties. The difference persisting, the indication would be that the greater adsorbing capacity of recently isolated strains was really related to larger amounts of the common antigen present (Tables 46 and 47. The results of the experiment excluded the possibility of the vi antigen being responsible. Other experiments, (Tables 48 to 53 using a 3 year old strain, demonstrated the modification in its antigenic constitution during

A. M. da Cunha

1942-01-01

257

A soro-aglutinação das Leishmanias / Agglutination of Leishmanias  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english The first agglutination experiments (Tables 1 and 2) showed that the serum obtained with any one strain of Leishmania, agglutinates all the others even of another species. This finding reveals the existence of a common antigen. However as the titre of agglutination did not permit a sharp differentia [...] tion of species we tried the adsorption method. The first adsorption tests made demonstrated differences in antigenic constitution between a strain of. L. donovani on one hand and strains of L. tropica or L. brasiliensis on the other. Further experiments in which L. chagasi was tested against the other species revealed that the former was antigenically different from the others. These tests were performed by adsorbing an anti-chagasi serum with organisms belonging to the other species or, conversely, adsorbing with L. chagasi sera prepared against the other species (See Tables 9 to 24). On the other hand, the adsorption of a serum prepared against one strain of l. chagasi by another of the same species showed that they had identifical antigenie constitution. These findings suggested the possibility of separating different species of Leishmania by this method. However, tests to separate the other species from one to another gave inconclusive results. (See Tables 27 to 35). It was soon observed that all the strains of L. chagasi were of recent isolation while all the others had been maintained in artificial culture media for a long time. We were led to believe that this condition was responsible for the differences in behaviour encountered. Accordingly, recently isolated strains of L. brasiliensis and L. donovani were tested and shown to be antigenically similar to strains of L. chagasi also recently isolated. The conclusion may be drawn that all strains have the same antigenic constitution when freshly isolated. It has been noted that when a serum which has been prepared against a freshly isolated is adsorbed with an old strain, the amount of agglutinins left free, is much smaller than when a serum prepared against an old strain is adsorbed with a newly isolated strain. At first, we thought to explain this by the low titre of the serum. However, the amount of agglutinins left free was not larger when higher titre serum was tested. The results do not corroborate the view of a special antigen being present in recently isolated strains (vi antige) but rather that the phenomenon is dependent on differences of the amount of the common antigen, more abundant in recent strains. In order to make this clear, experiments were made in which equal amounts of a serum prepared against a newly isolated strain were adsorbed by equal amounts, by weight, of, on one hand, a new strain, and the other an old strain. The resulting adsorbed sera were then titrated. (Table 44). Results showed that newly isolated strains adsorb a larger amount of agglutinins (Tables 44, 45). Two hypothesis have bem advanced to explain the stronger adsorbing qualities of the newly isolated strains. 1° - these strains possess larger amounts of the common antigen and 2° - they contain a vi antigen which adsorbed by the new strain together with the common antigen is the cause of their larger adsorbing capacity. To find out which of the two hypothesis corresponds to the reality a new experiment was made, similar to the one summarized in table 44. The adsorbed sera were made to act on a recently isolated strain as well as on an old one. The latter, not containing the vi antigen, the difference seen when sera act on new strains should not be observed here in the case of this antigen being responsible for the differences in adsorbing properties. The difference persisting, the indication would be that the greater adsorbing capacity of recently isolated strains was really related to larger amounts of the common antigen present (Tables 46 and 47). The results of the experiment excluded the possibility of the vi antigen being responsible. Other experiments, (Tables 48

A. M. da, Cunha.

258

Transmission potential of antimony-resistant leishmania field isolates.  

Science.gov (United States)

We studied the development of antimony-resistant Leishmania infantum in natural vectors Lutzomyia longipalpis and Phlebotomus perniciosus to ascertain the risk of parasite transmission by sand flies. All three resistant strains produced fully mature late-stage infections in sand flies; moreover, the resistant phenotype was maintained after the passage through the vector. These results highlight the risk of circulation of resistant Leishmania strains and question the use of human drugs for treatment of dogs as Leishmania reservoirs. PMID:25049256

Seblova, Veronika; Oury, Bruno; Eddaikra, Naouel; Aït-Oudhia, Khatima; Pratlong, Francine; Gazanion, Elodie; Maia, Carla; Volf, Petr; Sereno, Denis

2014-10-01

259

Shewanella amazonensis sp. nov., a novel metal-reducing facultative anaerobe from Amazonian shelf muds  

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A new bacterial species belonging to the genus Shewanella is described on the basis of phenotypic characterization and sequence analysis of its 16S rRNA-encoding and gyrase B (gyrB) genes. This organism, isolated from shallow-water marine sediments derived from the Amazon River delta, is a Gram-negative, motile, polarly flagellated, facultatively anaerobic, rod-shaped eubacterium and has a G&C content of 51.7 mol%. Strain SB2BT is exceptionally active in the anaerobic reduction of iron, manganese and sulfur compounds. SB2BT grows optimally at 35 degrees C, with 1-3% NaCl and over a pH range of 7-8. Analysis of the 16S rDNA sequence revealed a clear affiliation between strain SB2BT and members of the gamma subclass of the class Proteobacteria. High similarity values were found with certain members of the genus Shewanella, especially with Shewanella putrefaciens, and this was supported by cellular fatty acid profiles and phenotypic characterization. DNA-DNA hybridization between strain SB2BT and its phylogenetically closest relatives revealed low similarity values (24.6-42.7%) which indicated species status for strain SB2BT. That SB2BT represents a distinct bacterial species within the genus Shewanella is also supported by gyrB sequence analysis. Considering the source of the isolate, the name Shewanella amazonensis sp. nov. is proposed and strain SB2BT (= ATCC 700329T) is designated as the type strain.

Venkateswaran, K.; Dollhopf, M. E.; Aller, R.; Stackebrandt, E.; Nealson, K. H.

1998-01-01

260

Comparative genomic studies and in-silco strategies on Leishmania brazilensis, Leishmania infantum and Leishmania major: Conserved features, putative functions and potential drug target  

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Full Text Available Leishmaniasis is a parasitic disease found largely in the tropics, which the World Health Organization has estimated infects 12 million people worldwide each year. More recently cases have been reported in Europe among intravenous drug users with HIV. At least 20 Leishmania species infect humans. New world parasite Leishmania. braziliensis is the causative agent of mucocutaneous Leishmaniasis. The old world species Leishmania. major and Leishmania. infantum, which are present in Africa, Europe and Asia, are parasites that cause cutaneous and visceral Leishmaniasis respectively. Aim of this Study is determination of major common genes and Protein identified Gene location on each of the chromosomes, and identification of a common protein drug target Promastigote surface antigen with available lead molecule acetylglucosamine (6-(acetylamino-6-deoxyhexopyranose and docking studies on those considered Leishmania species.

Rakesh N. R.

2013-06-01

261

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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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, não usual, de várias formas amastigotas livres e intracelulares. Futuros estudos serão necessários a fim de determinar se a citologia de líquido ascítico representa uma ferramenta útil para o diagnóstico da infecção por Leishmania em cães com ascite, particularmente naqueles que vivem em áreas onde a leishmaniose canina é enzoótica.

Filipe Dantas-Torres

2006-08-01

262

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

Scientific Electronic Library Online (English)

Full Text Available Este trabalho relata as plantas usadas no tratamento da leishmaniose cutânea, causada por Leishmania (Viannia) braziliensis (L(V)b), 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 usa [...] das 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%. Abstract in english This paper records the plants used in the treatment of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis (L(V)b) 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 trea [...] t 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%.

Flávio, França; Ednaldo L., Lago; Philip D., Marsden.

1996-06-01

263

LA BIOLOGÍA MOLECULAR DE LEISHMANIA SPP. COMO PUNTO DE PARTIDA PARA NUEVAS ALTERNATIVAS DE TRATAMIENTO / AMOLECULAR BIOLOGY LEISHMANIA SPP NEW DRUGS RESISTANCE / A BIOLOGIA MOLECULAR DE LEISHMANIA SPP. COMO PONTO DE PARTIDA PARA NOVAS ALTERNATIVAS DE TRATAMENTO  

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Full Text Available Introdução: Na Colômbia existem grupos de pesquisas em Leishmaniasis que têm somado esforços para a identificação do genoma da Leishmania spp. Como profs-sionais da saúde, é uma prioridade conecé-los para entender os mecanismos de resistência a fármacos. Métodos: As bases de dados empregadas para es [...] ta busca foram, entre outras: NCBI PubMed, MEDLINE, Science Direct, Nucleic Acids Research e Molecular and Biochemical Parasitology, publicações da revista Biomédica e de varias Universidades. Resultados: existem muitas espécies de vetores distribuídos em todo o país. As multi-resistências criadas por Leishmania sp. baseiam-se especialmente em proteínas de membrana e mutações pontuais no DNA do parasita e seus vetores. Conclusões: As técnicas de PCR deveriam ser implementadas na clínica para estudar resistências a fármacos. Os protocolos atuais contra Leishmaniasis não incluem novas alternativas. Os tratamentos imuno-moduladores são uma nova es-perança para o tratamento desta enfermidade re-emergente. Abstract in spanish Introducción: en Colombia existen grupos de investigación en Leishmaniasis que han aunado esfuerzos para lograr la identificación del genoma de la Leishmania spp. Como profesionales de la salud es una prioridad conocerlos para entender los mecanismos de resistencia a fármacos. Métodos: las bases de [...] datos empleadas para esta búsqueda fueron entre otras: NCBI PubMed, MEDLINE, Science Direct, Nucleic Acids Research y Molecular and Biochemical Parasitology, publicaciones de la revista Biomédica y de varias Universidades. Resultados: existen muchas especies de vectores distribuidos en todo el país. Las multiresistencias creadas por Leishmania sp. se basan especialmente en proteínas de membrana y mutaciones puntuales en el DNA del parásito y sus vectores. Conclusiones: las técnicas de PCR deberían ser implementadas en la clínica para estudiar resistencias a fármacos. Los protocolos actuales contra Leishmaniasis no incluyen nuevas alternativas. Los tratamientos inmunomoduladores son una nueva esperanza para el tratamiento de esta enfermedad re-emergente. Abstract in english Introduction: In Colombia there are research groups in Leishmaniasis that have joined forces to achieve the identification of the genome of Leishmania spp. As health professionals know this is a priority to understand the mechanisms of drug resistance. Methods: The databases used for this search wer [...] e among others: NCBI PubMed MEDLINE, Science Direct, Nucleic Acids Research and Biochemical and Molecular Parasitology, as a publication of the journal Biomedical and several universities. Results: There are many species and vectors distributed throughout the country. The multiresistents created by Leishmania spp. rely especially in membrane proteins and mutations in the DNA of the parasite and their delivery systems. Conclusions: The PCR techniques should be implemented at the clinic to study resistance to drugs. The current protocols against Leishmaniasis not include additional alternatives. The treatments with immunomodulators are the new hope for treating this re-emerging disease.

Martha Cecilia, Beltrán Cifuentes; Patricia, Durán Ospina; Luisa Fernanda, Corredor Arias.

2008-04-01

264

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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Full Text Available 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 v [...] ariações 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. Abstract in english 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 mark [...] ers 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.

César Augusto, Cuba-Cuba; David, Evans; Ana de Cassia, Rosa; Philip Davis, Marsden.

1991-10-01

265

A small heat shock protein is essential for thermotolerance and intracellular survival of Leishmania donovani  

Science.gov (United States)

ABSTRACT Leishmania parasites must survive and proliferate in two vastly different environments – the guts of poikilothermic sandflies and the antigen-presenting cells of homeothermic mammals. The change of temperature during the transmission from sandflies to mammals is both a key trigger for the progression of their life cycle and for elevated synthesis of heat shock proteins, which have been implicated in their survival at higher temperatures. Although the functions of the main heat shock protein families in the Leishmania life cycle have been studied, nothing is known about the roles played by small heat shock proteins. Here, we present the first evidence for the pivotal role played by the Leishmania donovani 23-kDa heat shock protein (which we called HSP23), which is expressed preferentially during the mammalian stage where it assumes a perinuclear localisation. Loss of HSP23 causes increased sensitivity to chemical stressors and renders L. donovani non-viable at 37°C. Consequently, HSP23-null mutants are non-infectious to primary macrophages in vitro. All phenotypic effects could be abrogated by the introduction of a functional HSP23 transgene into the null mutant, confirming the specificity of the mutant phenotype. Thus, HSP23 expression is a prerequisite for L. donovani survival at mammalian host temperatures and a crucial virulence factor. PMID:25179594

Hombach, Antje; Ommen, Gabi; MacDonald, Andrea; Clos, Joachim

2014-01-01

266

Qualidade espermática de sêmen de cães naturalmente infectados por Leishmania sp: Semen quality of dogs naturally infected by Leishmania sp  

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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 the mitochondrial potential. The incidence of morphological changes in the seropositive animals did not promote an increase of injuries to the chromatin. All animals with leishmaniasis presented hyperproteinemia of the semen.

É. Labat

2010-06-01

267

Qualidade espermática de sêmen de cães naturalmente infectados por Leishmania sp: / Semen quality of dogs naturally infected by Leishmania sp  

Scientific Electronic Library Online (English)

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. Abstract in english 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 mo [...] rphology, 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 the mitochondrial potential. The incidence of morphological changes in the seropositive animals did not promote an increase of injuries to the chromatin. All animals with leishmaniasis presented hyperproteinemia of the semen.

É., Labat; J.T., Carreira; B.H., Matsukuma; M.T.A., Martins; V.M.F., Lima; S.R.M., Bomfim; S.H.V., Perri; M.B., Koivisto.

2010-06-01

268

Mucosal leishmaniasis due to Leishmania (Viannia) braziliensis L(V)b in Três Braços, Bahia-Brazil  

Scientific Electronic Library Online (English)

Full Text Available 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 indefinid [...] o. 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. Abstract in english 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 mysteri [...] ous although Leishmania (Viannia) braziliensis is the most common organism isolated. Perspectives for a more effective treatment, oral and cheap, are still remote.

Philip Davis, Marsden.

1994-06-01

269

Evaluation of enzyme-linked immunosorbent assay using crude Leishmania and recombinant antigens as a diagnostic marker for canine visceral leishmaniasis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The performances of ELISA assays with different antigen preparations, such as Leishmania amazonensis or L. chagasi lysates and the recombinant antigens rK-39 and rK-26, were compared using sera or eluates from dried blood collected on filter paper to detect anti-Leishmania antibodies in dogs from a [...] visceral leishmaniasis-endemic area in Brazil. Of 115 IFAT-reactive dogs at 1:40 titre, 106 (92.2%) were positive in parasitological exams (skin and/or spleen). These animals were compared to healthy animals (n = 25), negative for IFAT at a titre of 1:40 and parasitological exams. The sensitivities of crude and recombinant antigens were similar and remarkably high for both sera and eluates (97-100%). Specificity was higher than 96% for sera and eluates for different antigens, except for L. chagasi antigen using eluates (88%). Concordance values among the tests were higher either for sera or eluates (J = 0.95-1.00). High concordances were observed between sera and eluates tested with different antigens (kappa = 0.93-0.97). Crude and recombinant antigens identified different clinical phases of canine leishmaniasis. These results show that eluates could be used in canine surveys to identify L. chagasi infection. Recombinant antigens added little when compared to crude antigen in identifying positive dogs. Cross-reactivity with other diseases whose distribution often overlaps VL-endemic areas is a limitation of crude antigen use however.

Eliza Yoshie do, Rosário; Odair, Genaro; João C, França-Silva; Roberto T da, Costa; Wilson, Mayrink; Alexandre Barbosa, Reis; Mariângela, Carneiro.

2005-04-01

270

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

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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.

Elizaide L. A. Yoshida

1993-09-01

271

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 Atla [...] ntic 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.

Elizaide L. A., Yoshida; Cesar A Cuba, Cuba; Raquel da Silva, Pacheco; Elisa, Cupolillo; Celso Cruz, Tavares; Gerzia M. C., Machado; Hooman, Momen; Gabriel, Grimaldi Junior.

1993-09-01

272

Genes and Chromosomes of Leishmania infantum  

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Full Text Available During recent years, several Leishmania infantum genes have been cloned and characterized. Here, we have summarized the available information on the gene organization and expression in this protozoan parasite. From a comparative analysis, the following outstanding features were found to be common to most of the genes characterized: tandemly organized genes with conserved coding regions and divergent untranslated regions, polycistronic transcription and post-transcriptional regulation of gene expression. The analysis of chromosomes of L. infantum by pulsed-field electrophoresis showed the existence of both size and number polymorphisms such that each strain has a distinctive molecular karyotype. Despite this variability, highly conserved physical linkage groups exists among different strains of L. infantum and even among Old World Leishmania species. Gene mapping on the L. infantum molecular karyotype evidenced a bias in chromosomal distribution of, at least, the evolutionary conserved genes

Jose María Requena

1997-11-01

273

Genes and Chromosomes of Leishmania infantum  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english During recent years, several Leishmania infantum genes have been cloned and characterized. Here, we have summarized the available information on the gene organization and expression in this protozoan parasite. From a comparative analysis, the following outstanding features were found to be common to [...] most of the genes characterized: tandemly organized genes with conserved coding regions and divergent untranslated regions, polycistronic transcription and post-transcriptional regulation of gene expression. The analysis of chromosomes of L. infantum by pulsed-field electrophoresis showed the existence of both size and number polymorphisms such that each strain has a distinctive molecular karyotype. Despite this variability, highly conserved physical linkage groups exists among different strains of L. infantum and even among Old World Leishmania species. Gene mapping on the L. infantum molecular karyotype evidenced a bias in chromosomal distribution of, at least, the evolutionary conserved genes

Jose, María Requena; Manuel, Soto; Luis, Quijada; Carlos, Alonso.

1997-11-01

274

Experimental canine mucocutaneous leishmaniasis (Leishmania braziliensis braziliensis)  

OpenAIRE

Four mongrel dogs were intradermically inoculated with 3 x 10**6 Leishmania braziliensis braziliensis promastigotes. Three out of the four animals developed cutaneous lesions respectively 4, 7, and 8 months after. The fourth dog did not develop lesion at the inoculation site, but a mucosal ulcer was seen 16 months after the inoculum. Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease. These results su...

Claude Pirmez; Marzochi, Mauro C. A.; Coutinho, Sergio G.

1988-01-01

275

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

Scientific Electronic Library Online (English)

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. Abstract in english This paper presents an evaluation of the therapeutic effect of an hydroalcoholic extract of A. occidentale L. bark against Leishmania (Viannia) brasiliensis. The extract showed high activity in the in vitro model against the promastigotes ofthis species. However in the in vivo model no curative acti [...] vity was observed.

Flávio, França; César A.C., Cuba; Eduardo A., Moreira; Obdúlio, Miguel; Marcos, Almeida; Maria de L. das, Virgens; Philip D., Marsden.

1993-09-01

276

Identification of Novel Leishmania donovani Antigens that Help Define Correlates of Vaccine-Mediated Protection in Visceral Leishmaniasis  

OpenAIRE

Visceral leishmaniasis (VL), caused by the intracellular parasite Leishmania donovani is a major public health problem in the developing world. But there is no effective and safe vaccine approved for clinical use against any form of leishmaniasis. Through reactivity with kala-azar patient and cured sera, polypeptides ranging from 91 to 31-kDa from L. donovani promastigotes were previously identified as potential protective vaccine candidates. In this study four polypeptides 91(LD91), 72 (LD72...

Bhowmick, Sudipta; Ali, Nahid

2009-01-01

277

The first case report of Leishmania (leishmania) chagasi in Panthera leo in Brazil  

OpenAIRE

We reported here the first known case of natural infection of a lion (Panthera leo-Linnaeus, 1758) with Leishmania (Leishmania) chagasi (L. chagasi) in Brazil. The specimen was created by a circus handler in the state of Mato Grosso and was donated to the zoological park of the Federal University of Mato Grosso. Infection by L. chagasi was detected using a PCR-RFLP test. It was known that the domestic felids can act as reservoir of infection of L. chagasi in endemic areas, making it important...

Dahroug, Magyda Aa; Almeida, Arleana Bpf; Sousa, Vale?ria Rf; Dutra, Vale?ria; Guimara?es, Luciana D.; Soares, Ce?sar E.; Nakazato, Luciano; Souza, Roberto L.

2011-01-01

278

Zosteriform cutaneous leishmaniasis due to Leishmania ( Viannia ) panamensis and Leishmania ( Viannia ) braziliensis: report of three cases.  

Science.gov (United States)

In Colombia, zosteriform leishmaniasis is a little-known and infrequent clinical variant of cutaneous leishmaniasis. Its clinical features include one or more plaques made up of papules and pseudo-vesicles, which conform to a lineal pattern, as well as satellite lesions that affect one or more dermatomes, without crossing the median line. We present three zosteriform cutaneous leishmaniasis cases in which Leishmania panamensis and Leishmania braziliensis were identified as the infective species. In light of the fact that the disease occurs infrequently, diagnosis was reached by taking into account epidemiological and clinical suspicion. PMID:25504121

Morales, Camilo Andrés; Palacio, Juliana; Rodríguez, Gerzaín; Camargo, Yenny Carolina

2014-01-01

279

Disseminated Leishmania infantum infection in two sibling foxhounds due to possible vertical transmission  

OpenAIRE

Two sibling foxhounds born to a Leishmania seropositive bitch were presented after testing seropositive for Leishmania. Leishmania infantum infection was detected via histopathology, culture, and quantitative polymerase chain reaction (q-PCR). This is the first report of natural infection with Leishmania infantum with the possibility for vertical transmission in North America.

Gibson-corley, Katherine N.; Hostetter, Jesse M.; Hostetter, Shannon J.; Mullin, Kathleen; Ramer-tait, Amanda E.; Boggiatto, Paola M.; Petersen, Christine A.

2008-01-01

280

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 Mat [...] o 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. Abstract in english 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.

Nely Pinheiro, Souza; Arleana do Bom Parto Ferreira de, Almeida; Tatiana Pádua Tavares de, Freitas; Regina Celia Rodrigues da, Paz; Valéria, Dutra; Luciano, Nakazato; Valéria Régia Franco, Sousa.

2010-06-01

281

Detection of Leishmania donovani and L. tropicain Ethiopian wild rodents.  

Czech Academy of Sciences Publication Activity Database

Ro?. 145, May 2015 (2015), s. 39-44. ISSN 0001-706X R&D Projects: GA ?R GAP506/10/0983 Institutional support: RVO:68081766 Keywords : Leishmania donovani * Leishmania tropica * Phlebotomine sand fly * Rodents * kDNA * ITS1 Subject RIV: EG - Zoology Impact factor: 2.519, year: 2013

Kassahun, A.; Sádlová, J.; Dvo?ák, V.; Koš?álová, 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

282

Inhibition of Phagolysosomal Biogenesis by the Leishmania Lipophosphoglycan  

OpenAIRE

Whereas amastigotes of the protozoan parasite Leishmania proliferate inside acidic phagolysosomal vacuoles of the macrophage, vacuoles induced by Leishmania donovani promastigotes during initiation of infection are poorly characterized. Here, evidence is presented that interaction of these parasitophorous vacuoles with endocytic organelles is very limited. In contrast, vacuoles formed around L. donovani mutants lacking the cell surface lipophosphoglycan (LPG) fuse extensively with endosome...

Desjardins, Michel; Descoteaux, Albert

1997-01-01

283

Atypical epidermal alterations in chronic Leishmania mexicana mexicana lesions fo C3H mice  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Camundongos C3H cronicamente infectados com Leishmania mexicana mexicana, e em alguns grupos tratados com BCG ou levamisole, apresentaram alterações epidérmicas atípicas, incluindo hiperplasia pseudo+epiteliomatosa, displasia e hiperceratose. Estas alterações foram mais intensas em frequência e inte [...] nsidade durante o curso da infecção, porém não foram relacionadas com o tamanho da lesão ou com a carga parasitária tissular. Animais controles, respectivamente, normais com a mesma idade, tratados com BCG e levamisole, examinados simultaneamente, não mostraram tais modificações epidérmicas. Nos camundongos infectados, a derme e a hipoderme apresentaram um infiltrado inflamatório contendo histiócitos, linfócitos e plasmócitos, acompanhado por vezes de neutrófilos e eosinófilos, o qual não variou com a duração da infecção. Abstract in english C3H mice chronically infected with Leishmania m. mexicana, and in some groups treated with BCG or levamisole, presented atypical epidermal alterations, including pseudoepitheliomatous hyperplasia, hyperkeratosis and dysplasia. These alterations increased in frequency and intensity during the course [...] of infection, but were not related to lesion size or tissue parasite load. Age matched normal, BCG and levamisole treated control mice, examined simultaneously, did not show epidermal modifications. In infected mice the dermis and hypodermis presented an inflammatory infiltrate of histiocytes, lymphocytes and plasma cells, accompanied at times by neutrophils and eosinophils, which did not vary with duration of infection.

G., Grimaldi Junior; A. C., Queiroz; P. L., Moriearty.

1982-12-01

284

Terpenes increase the lipid dynamics in the Leishmania plasma membrane at concentrations similar to their IC50 values.  

Science.gov (United States)

Although many terpenes have shown antitumor, antibacterial, antifungal, and antiparasitic activity, the mechanism of action is not well established. Electron paramagnetic resonance (EPR) spectroscopy of the spin-labeled 5-doxyl stearic acid revealed remarkable fluidity increases in the plasma membrane of terpene-treated Leishmania amazonensis promastigotes. For an antiproliferative activity assay using 5×10(6) parasites/mL, the sesquiterpene nerolidol and the monoterpenes (+)-limonene, ?-terpineol and 1,8-cineole inhibited the growth of the parasites with IC50 values of 0.008, 0.549, 0.678 and 4.697 mM, respectively. The IC50 values of these terpenes increased as the parasite concentration used in the cytotoxicity assay increased, and this behavior was examined using a theoretical treatment of the experimental data. Cytotoxicity tests with the same parasite concentration as in the EPR experiments revealed a correlation between the IC50 values of the terpenes and the concentrations at which they altered the membrane fluidity. In addition, the terpenes induced small amounts of cell lysis (4-9%) at their respective IC50 values. For assays with high cell concentrations (2×10(9) parasites/mL), the incorporation of terpene into the cell membrane was very fast, and the IC50 values observed for 24 h and 5 min-incubation periods were not significantly different. Taken together, these results suggest that terpene cytotoxicity is associated with the attack on the plasma membrane of the parasite. The in vitro cytotoxicity of nerolidol was similar to that of miltefosine, and nerolidol has high hydrophobicity; thus, nerolidol might be used in drug delivery systems, such as lipid nanoparticles to treat leishmaniasis. PMID:25101672

Camargos, Heverton Silva; Moreira, Rodrigo Alves; Mendanha, Sebastião Antonio; Fernandes, Kelly Souza; Dorta, Miriam Leandro; Alonso, Antonio

2014-01-01

285

Single-Step Multiplex PCR Assay for Characterization of New World Leishmania Complexes  

OpenAIRE

We have developed a PCR assay for one-step differentiation of the three complexes of New World Leishmania (Leishmania braziliensis, Leishmania mexicana, and Leishmania donovani). This multiplex assay is targeted to the spliced leader RNA (mini-exon) gene repeats of these organisms and can detect all three complexes simultaneously, generating differently sized products for each complex. The assay is specific to the Leishmania genus and does not recognize related kinetoplastid protozoa, such as...

Harris, Eva; Kropp, Gerald; Belli, Alejandro; Rodriguez, Betzabe?; Agabian, Nina

1998-01-01

286

Cardiac and pulmonary alterations in symptomatic and asymptomatic dogs infectednaturally with Leishmania (Leishmania) chagasi  

OpenAIRE

Fifteen symptomatic and seven asymptomatic dogs infected naturally with Leishmania chagasi were examined in order to identify the presence of parasites and changes in heart and lung. Histopathological, cytological, and immunohistochemical analyses were performed on samples of heart and lung tissues. An inflammatory reaction characterized by inflammatory mononuclear, perivascular and intermuscular infiltrates was observed in both symptomatic and asymptomatic animals on histopathological analys...

Alves, G. B. B.; Pinho, F. A.; Silva, S. M. M. S.; Cruz, M. S. P.; Costa, F. A. L.

2010-01-01

287

Lutzomyia longipalpis naturally infected by Leishmania (L. chagasi in Várzea Grande, Mato Grosso State, Brazil, an area of intense transmission of visceral leishmaniasis Lutzomyia longipalpis naturalmente infectado por Leishmania (L. chagasi em Várzea Grande, Mato Grosso, Brasil, uma área de transmissão intensa de leishmaniose visceral  

Directory of Open Access Journals (Sweden)

Full Text Available The American visceral leishmaniasis (AVL is caused by parasites belonging to the genus Leishmania (Trypanosomatidae and is transmitted to humans through the bite of certain species of infected phlebotomine sand flies. In this study, we investigated the natural infection ratio of Lutzomyia longipalpis, the main vector species of AVL in Brazil, in Várzea Grande, Mato Grosso State. Between July 2004 and June 2006, phlebotomine sand flies were captured in peridomestic areas using CDC light-traps. Four hundred and twenty (420 specimens of Lu. longipalpis were captured. 42 pools, containing 10 specimens of Lu. longipalpis each, were used for genomic DNA extraction and PCR (polymerase chain reaction amplification. Leishmania spp. DNA was detected in three out of the 42 pools tested, resulting in a minimal infection ratio of 0.71%. Restriction fragment length polymorphism (RFLP analysis indicated that Leishmania (L. chagasi was the infective agent in the positive pools.A leishmaniose visceral americana (LVA é causada por parasitos pertencentes ao gênero Leishmania (Trypanosomatidae e transmitida ao homem através da picada de certas espécies de flebotomíneos, previamente infectados. Neste trabalho, investigamos o índice de infecção natural de Lutzomyia longipalpis, principal vetor da LVA no Brasil, em Várzea Grande, Estado do Mato Grosso. De julho de 2004 a junho de 2006, foram feitas capturas de flebotomíneos em áreas peridomésticas utilizando armadilhas de luz CDC. Foram capturadas 420 espécimens de Lu. longipalpis. Quarenta e dois grupos, formados por 10 espécimens de Lu. longipalpis cada um, foram submetidos à extração de DNA genômico e amplificação por PCR (reação em cadeia da polimerase. DNA de Leishmania spp. foi detectado em 3 dos 42 grupos testados, resultando em um índice mínimo de infecção de 0,71%. A análise de polimorfismos de fragmentos de restrição (RFLP indicou Leishmania (L. chagasi como a espécie infectante nos grupos positivos.

Nanci A. Missawa

2010-12-01

288

Pathology of dogs in Campo Grande, MS, Brazil naturally co-infected with Leishmania infantum and Ehrlichia canis / Patologia de cães naturalmente coinfectados por Leishmania infantum e Ehrlichia canis em Campo Grande, MS, Brasil  

Scientific Electronic Library Online (English)

Full Text Available A infecção simultânea por parasitas de diferentes espécies pode resultar em alterações imprevisíveis. O presente estudo avaliou a patologia de cães naturalmente coinfectados por Leishmania infantum e Ehrlichia canis. A saúde dos cães foi investigada pelas análises histopatológicas, hematológicas e b [...] ioquímicas de 21 cães infectados somente por L. infantum e 22 cães coinfectados por L. infantum e E. canis. Observou-se uma reação inflamatória crônica, predominantemente linfohistioplasmocítica, na pele dos dois grupos. A plasmocitose, encontrada nos tecidos linfóides, provavelmente estava relacionada com a hipergamaglobulinemia observada em todos os cães amostrados. A desorganização da matriz extracelular da derme da região inguinal e da orelha, demonstrada pela substituição das fibras de colágeno espessas por fibras finas, foi relacionada com o grau de reação inflamatória, independente da presença de parasitas. Ainda, observamos duas vezes mais animais do grupo coinfectado apresentando formas amastigotas na pele de orelha pela histopatologia comparado ao número de cães infectados apenas por Leishmania, tornando-os desta forma mais infectivos aos vetores. Nossos resultados ressaltam que a saúde de cães coinfectados estava severamente comprometida devido aos altos níveis de proteína plasmática total, globulinas, fosfatase alcalina, creatina quinase e anemia acentuada. Abstract in english Different parasites that commonly occur concomitantly can influence one another, sometimes with unpredictable effects. We evaluated pathological aspects of dogs naturally co-infected with Leishmania infantum and Ehrlichia canis. The health status of the dogs was investigated based on histopathologic [...] al, hematological and biochemical analyses of 21 animals infected solely with L. infantum and 22 dogs co- infected with L. infantum and E. canis. The skin of both groups showed chronic, predominantly lymphohistioplasmacytic inflammatory reaction. The plasmacytosis in the lymphoid tissues was likely related with the hypergammaglobulinemia detected in all the dogs. The disorganization of extracellular matrix found in the reticular dermis of the inguinal region and ear, characterized by the substitution of thick collagen fibers for thin fibers, was attributed to the degree of inflammatory reaction, irrespective of the presence of parasites. In addition, the histopathological analysis revealed that twice as many dogs in the co-infected group presented Leishmania amastigotes in the ear skin than those infected solely with Leishmania, increasing the possibility of becoming infected through sand fly vectors. Our findings highlight the fact that the health of dogs infected concomitantly with L. infantum and E. canis is severely compromised due to their high levels of total plasma protein, globulins, alkaline phosphatase and creatine kinase, and severe anemia.

Gisele Braziliano, Andrade; Wanessa Teixeira Gomes, Barreto; Luciana Ladislau dos, Santos; Laura Raquel Rios, Ribeiro; Gabriel Carvalho de, Macedo; Keyla Carstens Marques de, Sousa; Marcos Rogério, André; Rosangela Zacarias, Machado; Heitor Miraglia, Herrera.

2014-12-01

289

Pesquisa de infecção natural de flebotomíneos por Leishmania, no Estado do Paraná / Research of natural infection of phlebotomines for Leishmania, in the State of Paraná  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A leishmaniose tegumentar americana tem sido notificada em todos os estados do Brasil e no Paraná essa doença é endêmica. O objetivo deste trabalho foi detectar a infecção natural de flebotomíneos para verificar a competência vetorial destes insetos e a identificação da espécie parasitária. Os flebo [...] tomíneos foram coletados com armadilhas de Falcão e Shannon, nos municípios de Doutor Camargo, Fênix e Mandaguari, de novembro de 2005 a agosto de 2006. Coletaram-se 12.930 flebotomíneos, dos quais 2.487 fêmeas foram dissecadas e destes 1.230 fêmeas foram submetidas à reação em cadeia da polimerase. Pelo método da dissecação, foi detectada uma fêmea de Nyssomyia whitmani com infecção natural por flagelados e pela reação em cadeia da polimerase não se detectou a presença de DNA de Leishmania em nenhuma das fêmeas. Apesar de não ter sido detectada a infecção natural de Nyssomyia neivai nas localidades em apreço e ainda que os requisitos de incriminação vetorial não tenham sido atendidos, não se deve negligenciar o potencial vetorial desta espécie. Abstract in english American cutaneous leishmaniasis has been reported in all Brazilian states and in the Paraná this disease is endemic. The objective of this work was to detect natural infections in phlebotomines to verify the vector competence of these insects and the identification of the parasite species. Phleboto [...] mines were collected using Falcão and Shannon traps, in the municipalities of Doutor Camargo, Fênix and Mandaguari, between November 2005 and August 2006. from 12,930 phlebotomines were collected, 2,487 females were dissected and 1,230 dissected females had been submitted to polymerase chain reaction. Flagellates were detected in a female Nyssomyia whitmani that had been dissected and for polymerase chain reaction failed to detect Leishmania DNA in any females. Even though flagellates were not detected in Nyssomyia neivai it should still be considered as a potencial vector.

Herintha Coeto, Neitzke; Regiane Bertin de Lima, Scodro; Kárin Rosi Reinhold de, Castro; Alessandra de Cássia Dias, Sversutti; Thaís Gomes Verzignassi, Silveira; Ueslei, Teodoro.

2008-02-01

290

Identification and distribution of New World Leishmania species characterized by serodeme analysis using monoclonal antibodies.  

Science.gov (United States)

Five hundred thirty stocks of Leishmania isolated from human and domestic and wild reservoir hosts, representing a wide geographic distribution of endemic foci of American cutaneous (ACL) and visceral leishmaniases (AVL) were characterized and identified at species and/or subspecies levels based on their reactivity to a cross-panel of specific monoclonal antibodies using a radioimmune binding assay. This study confirms and extends our preliminary results on the high specificity of some of these monoclonals for the L. braziliensis, L. mexicana, and L. donovani complexes. This study also demonstrates the relative stability of these molecular markers and the general usefulness of the method for parasite identification. Two hundred ninety-two of 420 isolates of ACL were classified as members of the L. braziliensis complex. Two hundred twenty-seven were L. b. braziliensis; these showed the widest geographical distribution (Brazil: Amazonas, Bahia, Ceara, Espirito Santo, Goias, Minas Gerais, Para, Paraiba, Rio de Janeiro, and Sao Paulo; Honduras: Santa Barbara and Yoko; Peru: Ancash, Piura, and Ucayali; and Venezuela: Cojedes, Distrito Federal, Lara, Portuguesa, Vale Hondo, Yaracuy, and Zulia). Forty-one stocks were identified as L. b. guyanensis (from North Brazil: Amazonas, Amapa, Para, and Rondonia). Twenty-one stocks were identified as L. b. panamensis (from Costa Rica: Alajuela, Guanacasten, Limon, Puntarenas, and San Jose; and Honduras: El Paraiso, and Olancho). Out of 128 isolates classified as members of the L. mexicana complex, 74 were differentiated as L. m. amazonensis (from Bolivia; Brazil: Amazonas, Bahia, Ceara, Goias, Maranhao, Mato Grosso do Norte, and Para; Peru: Pasco Forest and Van Humboldt; and Venezuela: Carabobo, Guarico, and Merida). Forty-four stocks were identified as L. m. venezuelensis (from Venezuela: Lara). Six stocks were L. m. mexicana (from Belize; and Mexico: Campeche [corrected] and Quintana Roo, Yucatan). One hundred ten isolates from AVL were identified as L. donovani chagasi (from Brazil: Bahia, Ceara, Maranhao, Minas Gerais, Mato Grosso do Sul, Piaui, Rio de Janeiro, and Sergipe; and Honduras: Valle). The implications of these results with respect to both the clinical and epidemiological data (including the detection of seven unusual characterized stocks) are discussed. PMID:3826486

Grimaldi, G; David, J R; McMahon-Pratt, D

1987-03-01

291

DISTINCT CELLULAR MIGRATION INDUCED BY Leishmania infantum chagasi AND SALIVA FROM Lutzomyia longipalpis IN A HEMORRHAGIC POOL MODEL / Migração celular distinta induzida por Leishmania infantum chagasi e saliva de Lutzomyia longipalpis em um modelo de pool hemorrágico  

Scientific Electronic Library Online (English)

Full Text Available O recrutamento de uma população de células específicas após infecção por Leishmania pode influenciar o resultado da doença. A migração celular em resposta a Leishmania ou saliva do vetor tem sido reportada utilizando o modelo da bolsa de ar subcutânea, entretanto, a migração celular induzida por Lei [...] shmania associada com o sangue do hospedeiro e saliva do vetor neste modelo ainda não foi descrita. Neste trabalho foi investigada a migração celular no modelo da bolsa de ar subcutânea em hamster após a estimulação com a combinação de L. chagasi, sangue do hospedeiro e saliva de Lutzomyia longipalpis. A migração induzida por saliva foi três vezes maior do que a induzida por L. chagasi sozinha. Adicionalmente, L. chagasi associada com sangue e saliva induziu significativamente ainda mais leucócitos no exsudato inflamatório do que o estímulo com Leishmania sozinha. L. chagasi recrutou uma população de células distintas, no entanto, a maioria dessas células parece não ter migrado para o exsudato inflamatório, permanecendo no tecido da bolsa de ar. Estes resultados indicam que L. chagasi pode reduzir o acúmulo de leucócitos para o local inicial da infecção e que quando associada à saliva do vetor e na presença de componentes do sangue aumenta o influxo de mais neutrófilos do que macrófagos, sugerindo que o parasito desenvolveu uma estratégia para minimizar a resposta inflamatória inicial, permitindo uma progressão ilimitada dentro do hospedeiro. Este trabalho reforça a importância de mais estudos sobre os componentes da saliva dos vetores das leishmanioses no processo de transmissão e no estabelecimento da infecção. Abstract in english Recruitment of a specific cell population after Leishmania infection can influence the outcome of the disease. Cellular migration in response to Leishmania or vector saliva has been reported in air pouch model, however, cellular migration induced by Leishmania associated with host's blood and vector [...] saliva in this model has not been described. Herein we investigated cellular migration into air pouch of hamster after stimulation with combination of L. chagasi and host's blood and Lutzomyia longipalpis saliva. Migration induced by saliva was 3-fold more than those induced by L. chagasi alone. Additionally, L. chagasi associated with blood and saliva induced significantly even more leukocytes into air pouch than Leishmania alone. L. chagasi recruited a diverse cell population; however, most of these cells seem to have not migrated to the inflammatory exudate, remaining in the pouch lining tissue. These results indicate that L. chagasi can reduce leukocyte accumulation to the initial site of infection, and when associated with vector saliva in the presence of blood components, increase the influx of more neutrophils than macrophages, suggesting that the parasite has developed a strategy to minimize the initial inflammatory response, allowing an unlimited progression within the host. This work reinforces the importance of studies on the salivary components of sand fly vectors of leishmaniasis in the transmission process and the establishment of the infection.

Camila Oliveira, Vasconcelos; Zirlane C. Branco, Coelho; Cristina de Souza, Chaves; Clarissa Romero, Teixeira; Margarida M. Lima, Pompeu; Maria Jania, Teixeira.

2014-01-01

292

Charaterization of Leishmania major Friedlin Telomeric Terminus  

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Full Text Available SciELO Brazil | Language: English Abstract in english Here we have characterized Leishmania major (Friedlin) telomeric terminus (the very end) using recombinants obtained by a vector-adaptor cloning protocol. As in L. donovani, the last nine nucleotides of L. major terminus are 5'-GGTTAGGGT-OH 3', differing from Trypanosoma cruzi and T. brucei terminus [...] 5'GGGTTAGGG-OH 3', thus indicating that these sequences are genus specific. We have also made a comparative analysis between L. major and L. donovani telomere-associated sequences, and described a novel non-repeated telomeric associated sequence common to L. major low molecular weight chromosomal bands.

Miguel Angel, Chiurillo; José Luis, Ramírez.

2002-04-01

293

Detection of Leishmania infantum in Lutzomyia longipalpis captured in Campo Grande, MS / Detecção de Leishmania infantum em Lutzomyia longipalpis capturados em Campo Grande, MS  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese A Leishmaniose é uma zoonose causada por protozoários do gênero Leishmania (Ross 1903), objetos de considerável atenção em medicina humana e veterinária. Na cidade de Campo Grande – MS, o agente etiológico da Leishmaniose Visceral é Leishmania infantum (= L. chagasi), e o principal vetor é a espécie [...] Lutzomyia longipalpis, que representa cerca de 92,9% da população de flebotomíneos. Este trabalho teve como objetivo avaliar a PCR em tempo real como ferramenta para a detecção de kDNA de L. infantum em flebotomíneos, comparando-se com PCR convencional. Flebotomíneos dessa espécie foram capturados, somando 38 amostras de 1 a 4 espécimens cada, distribuídas em 13 bairros, divididos entre as 7 regiões urbanas da cidade de Campo Grande – MS, e armazenados a ?70 °C até a extração de ADN e amplificação por PCR e PCR em tempo real. Das 38 amostras testadas, foram encontradas 3 amostras positivas pela PCR convencional e 11 pela PCR em Tempo Real. Na otimização da PCR em tempo real, a temperatura de dissociação do amplificado foi de 82, 89 °C. Neste estudo, utilizando-se a técnica da PCR em tempo real, foi possível detectar a presença desse agente em 6 dos 13 bairros amostrados, todos na periferia da cidade, indicando o maior potencial enzoótico dessas regiões, que têm maior proximidade com reservas de matas naturais. Conclui-se que a PCR em tempo real pode ser utilizada para estudo epidemiológico de L. infantum. Abstract in english Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania (Ross, 1903) and is the focus of considerable attention in human and veterinary medicine. In the city of Campo Grande, MS, the causative agent of visceral leishmaniasis is Leishmania infantum (= L. chagasi) primary vector [...] , comprising approximately 92.9% of the local sandfly population, is Lutzomyia longipalpis. The aim of this work was to compare real-time PCR with PCR as a tool for the detection of the kinetoplast DNA (kDNA) of L. infantum in sandflies. Sandflies of this species were caught, and a total of 38 samples with 1-4 individuals in each sample were obtained; these were distributed across 13 districts and divided between seven urban areas of the city of Campo Grande, MS. Three positive samples were found by PCR and, when using real-time PCR, this was able to detect the presence of this agent in 6 of the 13 districts sampled, which were all located on the outskirts of the city, where indicates the greater enzootic potential of these regions, as they are closer to natural forest reserves. We conclude that real-time PCR can be used for epidemiological studies of L. infantum.

Rodrigo Casquero, Cunha; Renato, Andreotti; Marlon Cezar, Cominetti; Elaine Araújo, Silva.

2014-04-01

294

Histopathological findings and detection of parasites in the eyes of dogs infected naturally with Leishmania chagasi / Achados histopatológicos e detecção de parasitas nos olhos de cães infectados por Leishmania chagasi  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi estudar as alterações histopatológicas e a detecção do parasito nos olhos de cães naturalmente infectados por Leishmania chagasi. Utilizaram-se os olhos de 25 cães com exame parasitológico e sorológico positivo para Leishmania chagasi. Os animais foram submetidos à semi [...] otécnica oftálmica rotineira. Fragmentos do globo ocular foram coletados e destinados à imunoistoquímica e histopatologia. Entre as estruturas avaliadas, a conjuntiva da terceira pálpebra foi a que mais demonstrou imunomarcação da Leishmania chagasi. Na avaliação histopatológica, foi observado predominantemente infiltrado inflamatório mononuclear, variando de discreto a intenso nas diversas estruturas oculares. Congestão vascular e perivasculite também foram observadas. As alterações histopatológicas do bulbo do olho em cães com leishmaniose visceral podem estar relacionadas à presença do anticorpo. Abstract in english The objective of the present study was to investigate the histopathological alterations and detection of parasites that occur in the eyes of dogs naturally infected with Leishmania chagasi. The eyes of 25 dogs with a positive parasitological and serological exam for L. chagasi were submitted to rout [...] ine ophthalmic examination. Fragments were obtained from the eyeball and were analyzed by immunohistochemistry and histopathology. Among the structures studied, the conjunctiva of the third eyelid was the tissue most frequently stained for L. chagasi. Histopathological analysis revealed a predominantly mononuclear inflammatory infiltrate whose intensity ranged from discrete to intense in the various ocular structures. Vascular congestion and perivasculitis were also observed. The histopathological alterations that occur in the eyeball of dogs with visceral leishmaniasis might be related to the presence of antibodies.

Fábio Luiz da Cunha, Brito; José Luiz, Laus; Wagner Luiz, Tafuri; Maria Marta, Figueiredo; Valdemiro Amaro, Silva Júnior; Frederico Celso Lyra, Maia; Leucio Câmara, Alves.

1141-11-01

295

The change of behavior of two strains of Leishmania after cultivation in a defined medium Mudanças no comportamento de duas cepas de Leishmania após cultivo em meio definido  

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Full Text Available Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.Duas cepas de Leishmania originalmente isoladas in vitro de casos humanos de leishmaniose cutânea e que ab initio não infectaram animais de laboratório, tornaram-se infectantes para hamnsters após serem mantidos por vários anos em meio de cultura quimicamente definido. Foram realizadas observações sobre o crescimento de promastigotas in vitro, curso da infecção em hamsters, morfologia das amastigotas, mobilidade eletroforética de oito enzimas solúveis. Foram obtidas informações sobre a densidade de flutuação do n-DNA e do k-DNA e uma das cepas foi testada contra anticorpos monoclonais. Ambas as cepas permanecem sem identificação precisa.

M. N. Melo

1987-12-01

296

The change of behavior of two strains of Leishmania after cultivation in a defined medium / Mudanças no comportamento de duas cepas de Leishmania após cultivo em meio definido  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Duas cepas de Leishmania originalmente isoladas in vitro de casos humanos de leishmaniose cutânea e que ab initio não infectaram animais de laboratório, tornaram-se infectantes para hamnsters após serem mantidos por vários anos em meio de cultura quimicamente definido. Foram realizadas observações s [...] obre o crescimento de promastigotas in vitro, curso da infecção em hamsters, morfologia das amastigotas, mobilidade eletroforética de oito enzimas solúveis. Foram obtidas informações sobre a densidade de flutuação do n-DNA e do k-DNA e uma das cepas foi testada contra anticorpos monoclonais. Ambas as cepas permanecem sem identificação precisa. Abstract in english Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamste [...] rs, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.

M. N., Melo; Paul, Williams; N. M. Magalhães, Rocha; E. H., Babá; W., Mayrink; M. S. M., Michalick; C. A da, Costa; M., Dias; P. A., Magalhães.

1987-12-01

297

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  

OpenAIRE

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...

Silveira, Fernando T.; Ralph Lainson; Shaw, Jeffrey J.; Braga, Roseli R.; Ishikawa, Edna E. A.; Souza, Adelson A. A.

1991-01-01

298

Leishmaniose causada por Leishmania viannia braziliensis (Lvb) um caso de evolução atípica  

Scientific Electronic Library Online (English)

Full Text Available Os autores relatam o caso de uma criança portadora de Leishmaniose Tegumentar Americana causada por Leishmania braziliensis braziliensis que foi infectada durante a amamentação, desenvolvendo lesão infiltrativa e nodular nos lábios, com posterior disseminação para os seios da face, fossas nasais e p [...] avilhão auricular e cuja evolução clinica pós-terapêutica caracterizou-se por períodos sucessivos de regressão e de reativação da lesão. Enfatizam a gravidade do caso, e as dificuldades terapêuticas com a utilização dos antimoniais pentavalentes, antimoniato-N-metil glucamina (Glucantime) e o stibogluconato de sódio(Pentostam). Abstract in english The authors report a case of a child infected with Leishmania viannia braziliensis during breast feeding, who developed an infiltrated, granulomatous lesion of the lips, followed by dissemination to the face, nasal fossae and external ears. Post therapeutic clinical evolution was characterized by pe [...] riods of regression and lesion reactivation. The seriousness of the case, and the therapeutic difficulties with the utilization of pentavalent antimonials, meglumine antimoniate (glucantime) and sodium stibogluconate (Pentostam) are discussed.

Jackson Maurício Lopes, Costa; Kyola Costa, Vale; Flávio, França; Ednaldo L., Lago; Albino V., Magalhães; Philip D., Marsden; Raimunda N., Sampaio.

1988-06-01

299

Preliminary phytochemical and antileishmanial studies of the ethanolic extracts of Pterodon pudescens / Estudos preliminares sobre a fitoquimica e a atividade anti-leishmania de extratos etanólicos de Pterodon pudescens  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Antimoniais pentavalentes são a primeira escolha para o tratamento das leishmanioses humanas. No entanto, no interior brasileiro plantas tradicionais são usadas para o tratamento dessas lesões. De fato, recentes trabalhos tem relatado o potencial terapêutico de produtos naturais, especialmente deriv [...] ados de plantas. Neste estudo avaliamos a atividade leishmanicida de Pterodon pubescens, uma árvore nativa, distribuída pela região central brasileira e usada em infusões para tratamento de inflamações. Foi realizada a análise fitoquímica e o ensaio in vitro em macrófagos infectados com Leishmania amazonensis em concentrações de 150, 300, 450, 600 µg/ml do extrato etanólico de folhas de Pterodon pudescens (PPE) para comprovar o uso tradicional desta planta como terapia para as leishmanioses. Os testes fitoquímicos indicaram a presença de taninos catequímicos, flavonas, esteroides, triterpenoides, flavonoides e xantonas. Os ensaios biológicos revelaram que o PPE foi capaz de controlar a carga parasitária em macrófagos de maneira dose dependente. Estes resultados corroboram com o potencial terapêutico de compostos de Pterodon pudescens e, junto com sua ampla distribuição no Brasil, podem representar promissor agente leishmanicida. Abstract in english Pentavalent antimonials are the first choice for the treatment of human leishmaniasis. However in rural areas the traditional plants may be preferred for the treatment of lesions. In recent years a number of papers are published related to the natural products especially plant derivative with infect [...] ious diseases. The present work was undertaken to evaluate the antileishmanial activity of Pterodon pubescens which is a native tree widely distributed over the central region of Brazil and used in folk medicine as wine infusions to treat inflammatory disease. The phytochemical screening and the biological essay of ethanolic extract of Pterodon pudescens (PPE) leaves at the concentrations of 150, 300, 450, 600 µg/ml were tested in vitro in Leishmania amazonensis-infected macrophages to support its traditional medicinal use as a leishmaniasis remedy. Phytochemical screening of PPE has shown the presence of catechemical tannins, steroids, triterpenoids and flavonoids. The biological test suggests that PPE were found to control parasite burden of cell cultures in dose-dependent manner. These findings highlight the fact that the apparent potency of Pterodon pudescens compounds, together with their widely distribution over Latin America and Brazil, may represent a promising antileishmanial agent.

W.W., Arrais-Silva; P.S.G., Nunes; J.D., Carvalho; M.W., Brune; C., Arrais-Lima; C., Batalini.

2014-09-01

300

Experimental canine mucocutaneous leishmaniasis (Leishmania braziliensis braziliensis)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Quatro cães foram inoculados por via intredérmica com 3 x 10**6 promastigotos de Leishmania brasiliensis braziliensis. Três deles desenvolveram lesões no sítio do inóculo, mas uma úlcera mucosa foi detectada 16 meses após o inóculo. Os achados foram similares áqueles verificados na infecção canina n [...] atural, bem como na doença humana. Estes resultados sugerem que o cão pode representar um modelo experimental para a infecção causada pela L. b. brasiliensis. Abstract in english Four mongrel dogs were intradermically inoculated with 3 x 10**6 Leishmania braziliensis braziliensis promastigotes. Three out of the four animals developed cutaneous lesions respectively 4, 7, and 8 months after. The fourth dog did not develop lesion at the inoculation site, but a mucosal ulcer was [...] seen 16 months after the inoculum. Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease. These results suggest that dogs may be an useful model for L. b. braziliensis infection.

Claude, Pirmez; Mauro C. A., Marzochi; Sergio G., Coutinho.

1988-06-01

301

Experimental canine mucocutaneous leishmaniasis (Leishmania braziliensis braziliensis  

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Full Text Available Four mongrel dogs were intradermically inoculated with 3 x 10**6 Leishmania braziliensis braziliensis promastigotes. Three out of the four animals developed cutaneous lesions respectively 4, 7, and 8 months after. The fourth dog did not develop lesion at the inoculation site, but a mucosal ulcer was seen 16 months after the inoculum. Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease. These results suggest that dogs may be an useful model for L. b. braziliensis infection.Quatro cães foram inoculados por via intredérmica com 3 x 10**6 promastigotos de Leishmania brasiliensis braziliensis. Três deles desenvolveram lesões no sítio do inóculo, mas uma úlcera mucosa foi detectada 16 meses após o inóculo. Os achados foram similares áqueles verificados na infecção canina natural, bem como na doença humana. Estes resultados sugerem que o cão pode representar um modelo experimental para a infecção causada pela L. b. brasiliensis.

Claude Pirmez

1988-06-01

302

Reconstrucción quirúrgica tras destrucción nasal por Leishmania Panamensis Surgical reconstruction after nasal destruction by Leishmania Panamensis  

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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 leishmaniasis and the reconstructive surgery used are presented. A discussion of the differential diagnosis of oro-nasal tissues is also presented.

F. Vélez Bernal

2013-03-01

303

Quantitative proteomic analysis of amphotericin B resistance in Leishmania infantum  

OpenAIRE

•First large-scale quantitative proteomic study of amphotericin B resistance in Leishmania.•Identification of 97 differentially expressed proteins.•Upregulation of glycolysis and TCA cycle pathways.•Upregulation in reactive oxygen species scavenging and heat-shock proteins.

Brotherton, Marie-christine; Bourassa, Sylvie; Le?gare?, Danielle; Poirier, Guy G.; Droit, Arnaud; Ouellette, Marc

2014-01-01

304

Implications of a Neotropical Origin of the Genus Leishmania  

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Full Text Available The hypothesis of a Neotropical origin of the Leishmania/Endotrypanum clade is reviewed. The position of the L. (Sauroleishmania external to the subgenus L. (Leishmania is not consistent with the Neotropical origin of the latter subgenus. It is suggested that this may be a consequence of a faster evolutionary rate in the L. (Sauroleishmania. The implications for the classsification of the phlebotomine sandflies of the hypothesis for a Neotropical origin of the Leishmania is also considered. The classification of Galati (1995 is proposed to be most consistent with the hypothesis of a Neotropical origin of the Leishmania, whilst classifications which place the New and Old World species in separate taxa are inconsistent with this hypothesis.

Noyes Harry

1998-01-01

305

In vitro evaluation of new terpenoid derivatives against Leishmania infantum and Leishmania braziliensis  

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Full Text Available The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug [...] . The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.

Inmaculada, Ramírez-Macías; Clotilde, Marín; Rachid, Chahboun; Francisco, Olmo; Ibtisam, Messouri; Oscar, Huertas; María Jose, Rosales; Ramón, Gutierrez-Sánchez; Enrique, Alvarez-Manzaneda; Manuel, Sánchez-Moreno.

2012-05-01

306

Metastatic capability of Leishmania (Viannia) panamensis and Leishmania (Viannia) guyanensis in golden hamsters.  

Science.gov (United States)

The pattern and kinetics of internal dissemination and frequency of cutaneous metastatic lesions resulting from experimental infection of golden hamsters with Leishmania (Viannia) panamensis and Leishmania (Viannia) guyanensis were examined. Nineteen strains were evaluated: 16 L. (V.) panamensis isolated from patients and 3 L. (V.) guyanensis, 2 isolated from human cases and 1 WHO reference strain originating from a sandfly vector. Lymphatic dissemination occurred within 3 mo and was observed for 16 of 16 (100%) of L. (V.) panamensis and 3 of 3 (100%) of L. (V.) guyanensis. Parasites were cultured infrequently from liver and spleen: 3 of 125 (2%) L. (V.) panamensis and 1 of 22 (5%) L. (V.) guyanensis. Decreased frequency of isolation from the inoculation site and draining lymph nodes over time was accompanied by increased frequency of isolation from distant lymph nodes. Dilution of triturated tissue samples resulted in an increased efficiency of parasite culture. Both primary lesions and secondary cutaneous metastatic lesions were more severe in hamsters infected with L. (V.) guyanensis than with L. (V.) panamensis. Cutaneous metastatic lesions were produced more frequently by L. (V.) guyanensis, 24 of 46 hamsters (52%), than by L. (V.) panamensis, 28 of 252 hamsters (11%). Individual Leishmania strains displayed distinctive propensities to produce cutaneous metastases, manifested as a reproducible phenotype. Metastatic pathogenicity was independent of the inoculum dose, supporting the dissociation of infectivity and pathogenicity. PMID:1919926

Martinez, J E; Travi, B L; Valencia, A Z; Saravia, N G

1991-10-01

307

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

Scientific Electronic Library Online (English)

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.

Kárita Cláudia, Freitas-Lidani; Iara J de, Messias-Reason; Edna Aoba Y, Ishikawa.

2014-07-03

308

Trypanothione overproduction and resistance to antimonials and arsenicals in Leishmania.  

OpenAIRE

Leishmania resistant to arsenicals and antimonials extrude arsenite. Previous results of arsenite uptake into plasma membrane-enriched vesicles suggested that the transported species is a thiol adduct of arsenite. In this paper, we demonstrate that promastigotes of arsenite-resistant Leishmania tarentolae have increased levels of intracellular thiols. High-pressure liquid chromatography of the total thiols showed that a single peak of material was elevated almost 40-fold. The major species in...

Mukhopadhyay, R.; Dey, S.; Xu, N.; Gage, D.; Lightbody, J.; Ouellette, M.; Rosen, B. P.

1996-01-01

309

Canine experimental infection: intradermal inoculation of Leishmania infantum promastigotes  

OpenAIRE

Five mixed breed dogs were inoculated intradermally (ID) with cultured virulent stationary phase promastigotes of Leishmania infantum Nicole, 1908 stocks recently isolated. Parasite transformations in the skin of ID infected dogs were monitored from the moment of inoculation and for 48 h, by skin biopsies. Anti-Leishmania antibody levels were measured by indirect immunofluorescence assay, counterimmunoelectrophoresis and direct agglutination test, and clinical conditions were examined. Thirty...

Santos-Gomes Gabriela M; Campino Lenea; Abranches Pedro

2000-01-01

310

Leishmania (Viannia) Infection in the Domestic Dog in Chaparral, Colombia  

OpenAIRE

Peridomestic transmission of American cutaneous leishmaniasis is increasingly reported and dogs may be a reservoir of Leishmania (Viannia) in this setting. We investigated the prevalence of infection in dogs in Chaparral County, Colombia, the focus of an epidemic of human cutaneous leishmaniasis caused by Leishmania (Viannia) guyanensis. Two (0.72%) of 279 dogs had lesions typical of cutaneous leishmaniasis that were biopsy positive by kinetoplast DNA polymerase chain reaction–Southern blot...

Santaella, Julia?n; Ocampo, Clara B.; Saravia, Nancy G.; Me?ndez, Fabia?n; Go?ngora, Rafael; Gomez, Maria Adelaida; Munstermann, Leonard E.; Quinnell, Rupert J.

2011-01-01

311

Heterogeneity of Leishmania infantum chagasi Kinetoplast DNA in Teresina (Brazil)  

OpenAIRE

Leishmania infantum chagasi is the causative agent of visceral leishmaniasis in Brazil. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of kinetoplast DNA (kDNA) minicircles was used to evaluate genetic profiles of 48 Leishmania infantum chagasi strains from dog and human parasite cultures, fresh collected dog bone marrow aspirates, and from infected sand flies. Results revealed that heterogeneity in kDNA minicircles depends mostly on the source of the s...

Alonso, Diego Peres; Costa, Dorcas Lamounier; Mendonc?a, Ivete Lopes; Costa, Carlos Henrique Nery; Ribolla, Paulo Eduardo Martins

2010-01-01

312

Histopathological and immunohistochemical study of the gastrointestinal tract from a dog naturally infected with Leishmania (Leishmania) chagasi: a case report Histopatologia e imunoistoquímica do trato gastrintestinal em cão naturalmente infectado com Leishmania (Leishmania) chagasi: relato de caso  

OpenAIRE

Samples of stomach, duodenum, jejunun, ileum, cecum and colon were collected for Giemsa-smears ("imprints") from one asymptomatic mongrel dog, naturally infected with Leishmania (L) chagasi. Other fragments were obtained and fixed in formalin (10% and buffered) for histopathological and immunohistochemical studies. The immunohistochemistry was carried out by a streptavidin-peroxidase technique and it allowed to detect amastigote forms of Leishmania chagasi in the different paraffin gut sectio...

Silva, F. L.; Tafuri, W. L.; Oliveira, M. R.; Tafuri, Wg L.

2002-01-01

313

Pathways of iron acquisition and utilization in Leishmania  

OpenAIRE

Iron is essential for many metabolic pathways, but is toxic in excess. Recent identification of the ferric iron reductase LFR1, the ferrous iron transporter LIT1, and the heme transporter LHR1 greatly advanced our understanding of how Leishmania parasites acquire iron and regulate its uptake. LFR1 and LIT1 have close orthologs in plants, and are required for Leishmania virulence. Consistent with the lack of heme biosynthesis in trypanosomatids, LHR1 and LABCG5, a protein involved in heme salv...

Flannery, Andrew R.; Renberg, Rebecca L.; Andrews, Norma W.

2013-01-01

314

Response of Leishmania chagasi promastigotes to oxidant stress.  

OpenAIRE

At the onset of infection, Leishmania promastigotes are phagocytized by mammalian macrophages. They must survive despite exposure to toxic oxidants such as hydrogen peroxide (H2O2) and superoxide (.O2-) generated during phagocytosis. We investigated the effects of these oxidants on Leishmania chagasi promastigotes and promastigote mechanisms for oxidant resistance. According to spin trapping and electron paramagnetic resonance spectrometry, .O2- could be generated by exposure of promastigotes...

Wilson, M. E.; Andersen, K. A.; Britigan, B. E.

1994-01-01

315

An improved purification procedure for Leishmania RNA virus (LRV)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Leishmania RNA Virus (LRV, Totiviridae) infect Leishmania cells and subvert mice immune response, probably promoting parasite persistence, suggesting significant roles for LRV in host-parasite interaction. Here we describe a new LRV1-4 purification protocol, enabling capsid visualization by negative [...] ly stained electron microscopy representing a significant contribution to future LRV investigations.

Marcos Michel de, Souza; Livia Regina, Manzine; Marcos Vinicius G. da, Silva; Jefferson, Bettini; Rodrigo Vilares, Portugal; Angela Kaysel, Cruz; Eurico, Arruda; Otavio Henrique, Thiemann.

2014-06-01

316

The role of phosphoglycans in Leishmania–sand fly interactions  

OpenAIRE

Leishmania promastigotes synthesize an abundance of phosphoglycans, either attached to the cell surface through phosphatidylinositol anchors (lipophosphoglycan, LPG) or secreted as protein-containing glycoconjugates. These phosphoglycans are thought to promote the survival of the parasite within both its vertebrate and invertebrate hosts. The relative contributions of different phosphoglycan-containing molecules in Leishmania–sand fly interactions were tested by using mutants specifically d...

Sacks, David L.; Modi, Govind; Rowton, Edgar; Spa?th, Gerald; Epstein, Linda; Turco, Salvatore J.; Beverley, Stephen M.

2000-01-01

317

Performance of commercially available serological diagnostic tests to detect Leishmania infantum infection on experimentally infected dogs.  

Science.gov (United States)

Leishmania infantum (syn. Leishmania chagasi) is the etiological agent of a widespread serious zoonotic disease that affects both humans and dogs. Prevalence and incidence of the canine infection are important parameters to determine the risk and the ways to control this reemergent zoonosis. Unfortunately, there is not a gold standard test for Leishmania infection. Our aim was to assess the operative validity of commercial tests used to detect antibodies to Leishmania in serum samples from experimental infections. Three ELISA tests (LEISCAN(®) Leishmania ELISA Test, INGEZIM(®) LEISHMANIA, and INGEZIM(®) LEISHMANIA VET), three immunochromatographic tests (INGEZIM(®) LEISHMACROM, SNAP(®) Leishmania, and WITNESS(®) Leishmania), and one IFAT were evaluated. LEISCAN(®) Leishmania ELISA test achieved the highest sensitivity and accuracy (both 0.98). Specificity was 1 for all tests except for IFAT. All tests but IFAT obtained a positive predictive value of 1, while the maximum negative predictive value was achieved by LEISCAN(®) Leishmania ELISA Test (0.93). The best positive likelihood ratio was obtained by INGEZIM(®) LEISHMANIA VET (30.26), while the best negative likelihood ratio was obtained by LEISCAN(®) Leishmania ELISA Test (0.02). The highest diagnostic odds ratio was achieved by LEISCAN(®) Leishmania ELISA Test (729.00). The largest area under the ROC curve was obtained by LEISCAN(®) Leishmania ELISA Test (0.981). Quantitative ELISA based tests performmed better than qualitative tests ("Rapid Tests"), and the test best suited to detect Leishmania in infected dogs and to provide clinically useful information was LEISCAN(®) Leishmania ELISA Test. This and other results point also to the need of revising the status of IFAT as a gold standard for the diagnosis of leishmaniasis. PMID:23021261

Rodríguez-Cortés, Alhelí; Ojeda, Ana; Todolí, Felicitat; Alberola, Jordi

2013-01-31

318

Leishmaniose tegumentar, visceral e doença de Chagas caninas em municípios do Triângulo Mineiro e Alto Paranaíba, Minas Gerais, Brasil Canine cutaneous and visceral leishmaniasis and Chagas' disease from counties in the Triângulo Mineiro and Alto Paranaíba regions, Minas Gerais State, Brazil  

OpenAIRE

Inquérito envolvendo leishmaniose e doença de Chagas, por meio da Reação de Imunofluorescência Indireta, foi realizado com soros de 331 cães de Uberlândia e Coromandel, Municípios do Estado de Minas Gerais, Brasil. Para tal inquérito, utilizaram-se, como antígenos, Leishmania amazonensis e Trypanosoma cruzi. No que tange a Uberlândia, examinaram-se 230 soros, sendo 200 da área urbana com 4,5% de positividade, e 30 da área rural, dos quais, 6,6% positivos para a RIFI com antígeno...

Paula Guardenho Maywald; Maria Inês Machado; Julia Maria Costa-Cruz; Maria do Rosário de Fátima Gonçalves-Pires

1996-01-01

319

Proteomics advances in the study of Leishmania parasites and leishmaniasis.  

Science.gov (United States)

Leishmania spp. are digenetic parasites which cause a broad spectrum of fatal diseases in humans. These parasites, as well as the other trypanosomatid, regulate gene expression at the post-transcriptional and post-translational levels, so that a poor correlation is observed between mRNA content and translated proteins. The completion of the genomic sequencing of several Leishmania species has enormous relevance to the study of the leishmaniasis pathogenesis. The combination of the available genomic resources of these parasites with powerful high-throughput proteomic analysis has shed light on various aspects of Leishmania biology as well as on the mechanisms underlying the disease. Diverse proteomic approaches have been used to describe and catalogue global protein profiles of Leishmania spp., reveal changes in protein expression during development, determine the subcellular localization of gene products, evaluate host-parasite interactions and elucidate drug resistance mechanisms. The characterization of these proteins has advanced, although many fundamental questions remain unanswered. Here, we present a historic review summarizing the different proteomic technologies applied to the study of Leishmania parasites during the last decades and we discuss the proteomic discoveries that have contributed to the understanding of Leishmania parasites biology and leishmaniasis. PMID:24264252

de Jesus, Jose Batista; Mesquita-Rodrigues, Camila; Cuervo, Patricia

2014-01-01

320

Proteases de Leishmania: novos alvos para o desenvolvimento racional de fármacos / Leishmania proteases: new targets for rational drug development  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english Leishmania causes tegumental and visceral diseases called leishmaniasis. Disease control is possible interrupting the transmission cycle, but HIV co-infection, chemotheraphy toxicity and lack of a vaccine are paramount difficulties. So, is necessary to study new Leishmania molecules and investigate [...] the possibility to develop rational drugs using these molecules as targets. Leishmania express many peptidases during their life, and cysteine are the most abundant protease and many inhibitors were developed but failed to kill parasites. On the other hand, inhibitors of serine proteases killed promastigotes, indicating the possibility of these enzymes to be important targets in the development of anti-Leishmania drugs.

Raquel Elisa da, Silva-López.

1541-15-01

321

Histopathological and immunohistochemical study of the gastrointestinal tract from a dog naturally infected with Leishmania (Leishmania) chagasi: a case report  

OpenAIRE

Samples of stomach, duodenum, jejunun, ileum, cecum and colon were collected for Giemsa-smears ("imprints") from one asymptomatic mongrel dog, naturally infected with Leishmania (L) chagasi. Other fragments were obtained and fixed in formalin (10% and buffered) for histopathological and immunohistochemical studies. The immunohistochemistry was carried out by a streptavidin-peroxidase technique and it allowed to detect amastigote forms of Leishmania chagasi in the different paraffin gut sectio...

Silva F.L.; Tafuri W.L.; Oliveira M.R.; Tafuri Wg. L.

2002-01-01

322

Leishmania (Leishmania) chagasi-infected mice as a model for the study of glomerular lesions in visceral leishmaniasis  

OpenAIRE

Renal involvement in visceral leishmaniasis (VL) is very frequent but the pathogenesis of this nephropathy is poorly understood. In previous studies using dogs with VL we have detected new immunopathological elements in the glomeruli such as T cells and adhesion molecules. Although Leishmania (Leishmania) chagasi-infected dogs and hamsters are considered to be good models for VL, their use is limited for immunopathologic studies. The use of isogenic mouse strains susceptible to L. (L.) chagas...

Prianti, M. G.; Yokoo, M.; Saldanha, L. C. B.; Costa, F. A. L.; Goto, H.

2007-01-01

323

Deficiency of Leishmania Phosphoglycans Influences the Magnitude but Does Not Affect the Quality of Secondary (Memory) Anti-Leishmania Immunity  

OpenAIRE

Despite inducing very low IFN-? response and highly attenuated in vivo, infection of mice with phosphoglycan (PG) deficient Leishmania major (lpg2-) induces protection against virulent L. major challenge. Here, we show that mice infected with lpg2- L. major generate Leishmania-specific memory T cells. However, in vitro and in vivo proliferation, IL-10 and IFN-? production by lpg2- induced memory cells were impaired in comparison to those induced by wild type (WT) parasites. Interestingly, T...

Liu, Dong; Okwor, Ifeoma; Mou, Zhirong; Beverley, Stephen M.; Uzonna, Jude E.

2013-01-01

324

[Quantitative PCR in the diagnosis of Leishmania].  

Science.gov (United States)

Polymerase chain reaction (PCR) is a sensitive and rapid method for the diagnosis of canine Leishmania infection and can be performed on a variety of biological samples, including peripheral blood, lymph node, bone marrow and skin. Standard PCR requires electrophoretic analysis of the amplification products and is usually not suitable for quantification of the template DNA (unless competitor-based or other methods are developed), being of reduced usefulness when accurate monitoring of target DNA is required. Quantitative real-time PCR allows the continuous monitoring of the accumulation of PCR products during the amplification reaction. This allows the identification of the cycle of near-logarithmic PCR product generation (threshold cycle) and, by inference, the relative quantification of the template DNA present at the start of the reaction. Since the amplification product are monitored in "real-time" as they form cycle-by-cycle, no post-amplification handling is required. The absolute quantification is performed according either to an internal standard co-amplified with the sample DNA, or to an external standard curve obtained by parallel amplification of serial known concentrations of a reference DNA sequence. From the quantification of the template DNA, an estimation of the relative load of parasites in the different samples can be obtained. The advantages compared to standard and semi-quantitative PCR techniques are reduction of the assay's time and contamination risks, and improved sensitivity. As for standard PCR, the minimal components of the quantitative PCR reaction mixture are the DNA target of the amplification, an oligonucleotide primer pair flanking the target sequence, a suitable DNA polymerase, deoxynucleotides, buffer and salts. Different technologies have been set up for the monitoring of amplification products, generally based on the use of fluorescent probes. For instance, SYBR Green technology is a non-specific detection system based on a fluorescent dsDNA intercalator and it is applicable to all potential targets. TaqMan technology is more specific since performs the direct assessment of the amount of amplified DNA using a fluorescent probe specific for the target sequence flanked by the primer pair. This probe is an oligonucleotide labelled with a reporter dye (fluorescent) and a quencher (which absorbs the fluorescent signal generated by the reporter). The thermic protocol of amplification allows the binding of the fluorescent probe to the target sequence before the binding of the primers and the starting of the polymerization by Taq polymerase. During polymerization, 5'-3' exonuclease activity of Taq polymerase digests the probe and in this way the reporter dye is released from the probe and a fluorescent signal is detected. The intensity of the signal accumulates at the end of each cycle and is related to the amount of the amplification product. In recent years, quantitative PCR methods based either on SYBR Green or TaqMan technology have been set up for the quantification of Leishmania in mouse liver, mouse skin and human peripheral blood, targeting either single-copy chromosomal or multi-copy minicircle sequences with high sensitivity and reproducibility. In particular, real-time PCR seems to be a reliable, rapid and noninvasive method for the diagnosis and follow up of visceral leishmaniasis in humans. At present, the application of real-time PCR for research and clinical diagnosis of Leishmania infection in dogs is still foreseable. As for standard PCR, the high sensitivity of real-time PCR could allow the use of blood sampling that is less invasive and easily performed for monitoring the status of the dogs. The development of a real-time PCR assay for Leishmania infantum infection in dogs could support the standard and optimized serological and PCR methods currenly in use for the diagnosis and follow-up of canine leishmaniasis, and perhaps prediction of recurrences associated with tissue loads of residual pathogens after treatment. At this regard, a TaqMan Real Time PCR method dev

Mortarino, M; Franceschi, A; Mancianti, F; Bazzocchi, C; Genchi, C; Bandi, C

2004-06-01

325

Cutaneous leishmaniasis in northeastern Brazil: a critical appraisal of studies conducted in State of Pernambuco / Leishmaniose cutânea no nordeste do Brasil: uma avaliação crítica dos estudos realizados no Estado de Pernambuco  

Scientific Electronic Library Online (English)

Full Text Available A leishmaniose cutânea americana (LCA) é uma doença complexa com características clínicas e epidemiológicas que podem variar de região para região. De fato, pelo menos, sete diferentes espécies de Leishmania, incluindo Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis, Leishmania (V [...] iannia) lainsoni, Leishmania (Viannia) naiffi, Leishmania (Viannia) shawi, Leishmania (Viannia)