Antibodies to Toxoplasma gondii and Leishmania spp. in domestic cats from Luanda, Angola

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Toxoplasma gondii and Leishmania spp. are zoonotic agents of importance to public health, with domestic cats as potential reservoirs for both protozoal infections. The present study aimed at assessing for the first time the seroprevalence of these zoonotic parasites in a domestic feline population l...

Seroepidemiology of Leishmania spp. in dogs residing in Telêmaco Borba, Paraná, Brazil

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Caroline Constantino

2014-12-01

Full Text Available Leishmaniasis is an important metazoonosis caused by protozoa of the genus Leishmania and has a heteroxenic life cycle involving invertebrate and vertebrate hosts. Transmission occurs during the blood meal of infected phlebotomine sand flies in wild species, domestic animals, and humans. The dog is a reservoir for the parasite causing visceral leishmaniasis (VL, whereas in American tegumentary leishmaniasis (ATL, dogs are erratic hosts that are accidentally infected, as in humans. Dogs are considered an important indicator of the parasite and its vectors in the environment, thus highlighting the importance of diagnosis in these animals. This study aimed to assess the seroepidemiology of Leishmania spp. in dogs in the municipality of Telêmaco Borba that were part of a castration campaign. Blood samples from 191 dogs were collected, and their owners were surveyed on various epidemiological variables. Serological analysis was performed using indirect immunofluorescence (IIF and rapid immunochromatography (DPP®. Screening by IIF identified 13 (6.81% positive animals, none of which were positive for the DPP® test, which is specific for VL. Statistical analysis of the questionnaire responses indicated a significant association between seropositivity and the presence of stacked or composting leaves in the backyard (p = 0.0498, forest areas (squares, woods, parks near the residence (p = 0.0015, and poorly healing ulcerated or nodular epidermal lesions in the dog (p = 0.0138. This study revealed the presence of anti-Leishmania spp. IgG antibodies in dogs residing in Telêmaco Borba, suggesting the presence of the parasite and vector in the environment. In addition, the existence of stacked or composting leaves in the backyard, forest areas near the residence, and epidermal lesions in dogs are factors associated with Leishmania spp. infection in pet dogs.

Antibodies to Toxoplasma gondii and Leishmania spp. in domestic cats from Luanda, Angola

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Lopes, Ana Patrícia; Oliveira, Ana Cristina; Granada, Sara; Rodrigues, Filipa T.; Papadopoulos, Elias; Schallig, Henk; Dubey, Jitender P.; Cardoso, Luís

2017-01-01

Toxoplasma gondii and Leishmania spp. are zoonotic protozoa of importance to animal and public health. The present study aimed to assess for the first time the seroprevalence of these zoonotic parasites in a domestic feline population living in Luanda, Angola. One hundred and two cats were sampled

Molecular detection of Leishmania spp. in road-killed wild mammals in the Central Western area of the State of São Paulo, Brazil.

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Richini-Pereira, Virginia Bodelão; Marson, Pamela Merlo; Hayasaka, Enio Yoshinori; Victoria, Cassiano; da Silva, Rodrigo Costa; Langoni, Hélio

2014-01-01

Road-killed wild animals have been classified as sentinels for detecting such zoonotic pathogens as Leishmania spp., offering new opportunities for epidemiological studies of this infection. This study aimed to evaluate the presence of Leishmania spp. and Leishmania chagasi DNA by PCR in tissue samples (lung, liver, spleen, kidney, heart, mesenteric lymph node and adrenal gland) from 70 road-killed wild animals. DNA was detected in tissues of one Cavia aperea (Brazilian guinea pig), five Cerdocyon thous (crab-eating fox), one Dasypus septemcinctus (seven-banded armadillo), two Didelphis albiventris (white-eared opossum), one Hydrochoerus hydrochoeris (capybara), two Myrmecophaga tridactyla (giant anteater), one Procyon cancrivorus (crab-eating raccoon), two Sphiggurus spinosus (porcupine) and one Tamandua tetradactyla (lesser anteater) from different locations in the Central Western part of São Paulo state. The Leishmania chagasi DNA were confirmed in mesenteric lymph node of one Cerdocyon thous. Results indicated common infection in wild animals. The approach employed herein proved useful for detecting the environmental occurrence of Leishmania spp. and L. chagasi, as well as determining natural wild reservoirs and contributing to understand the host-parasite interaction.

Coinfection by Toxoplasma gondii and Leishmania spp. in domestic cats (Felis catus in State of Mato Grosso do Sul

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Audrey Rennó Campos Braga

2014-12-01

Full Text Available Introduction Leishmaniasis and toxoplasmosis are important to public health. Methods Antibodies for Toxoplasma gondii and Leishmania spp. were evaluated in cats from Campo Grande, State of Mato Grosso do Sul, Brazil, a region endemic for canine visceral leishmaniasis. Serum samples from 50 asymptomatic cats were titrated for T. gondii by the immunofluorescence antibody test and modified agglutination test and for Leishmania spp. by the immunofluorescence antibody test. Results These two agents coinfected two (4% of the 50 tested animals. Conclusions These findings demonstrate the concomitant presence of two important zoonoses in cats from Brazilian endemic regions for canine visceral leishmaniasis.

Detection and identification of Leishmania spp.: application of two hsp70-based PCR-RFLP protocols to clinical samples from the New World.

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Montalvo, Ana M; Fraga, Jorge; Tirado, Dídier; Blandón, Gustavo; Alba, Annia; Van der Auwera, Gert; Vélez, Iván Darío; Muskus, Carlos

2017-07-01

Leishmaniasis is highly prevalent in New World countries, where several methods are available for detection and identification of Leishmania spp. Two hsp70-based PCR protocols (PCR-N and PCR-F) and their corresponding restriction fragment length polymorphisms (RFLP) were applied for detection and identification of Leishmania spp. in clinical samples recruited in Colombia, Guatemala, and Honduras. A total of 93 cases were studied. The samples were classified into positive or suspected of leishmaniasis according to parasitological criteria. Molecular amplification of two different hsp70 gene fragments and further RFLP analysis for identification of Leishmania species was done. The detection in parasitologically positive samples was higher using PCR-N than PCR-F. In the total of samples studied, the main species identified were Leishmania panamensis, Leishmania braziliensis, and Leishmania infantum (chagasi). Although RFLP-N was more efficient for the identification, RFLP-F is necessary for discrimination between L. panamensis and Leishmania guyanesis, of great importance in Colombia. Unexpectedly, one sample from this country revealed an RFLP pattern corresponding to Leishmania naiffi. Both molecular variants are applicable for the study of clinical samples originated in Colombia, Honduras, and Guatemala. Choosing the better tool for each setting depends on the species circulating. More studies are needed to confirm the presence of L. naiffi in Colombian territory.

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

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

2013-03-01

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

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

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Mário A. P. Moraes

1994-10-01

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

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

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Raquel S. Pacheco

1987-12-01

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

Serosurvey for Leishmania spp., Toxoplasma gondii, Trypanosoma cruzi and Neospora caninum in neighborhood dogs in Curitiba-Paraná, Brazil

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Caroline Constantino

Full Text Available Abstract Neighborhood dogs may act as reservoirs for several zoonotic protozoan infections, particularly in urban areas, thus constituting a potential public health threat. Accordingly, the aim of the present study was to evaluate the exposure of neighborhood dogs to four protozoan pathogens in public areas with high levels of human movement in Curitiba, southern Brazil. Blood samples from 26 neighborhood dogs were screened by means of the indirect immunofluorescent antibody test (IFAT for Leishmania spp., Toxoplasma gondii, Trypanosoma cruzi and Neospora caninum, and a questionnaire was answered by the respective keeper. A total of 8/26 dogs (30.7% seroreactive to T. gondii, 3/26 (11.5% to N. caninum and 2/26 (7.7% to both were identified. All the samples were seronegative for T. cruzi and Leishmania spp. Pathogen seroreactivity was not associated with the daily human movements or other epidemiological variables investigated (p > 0.05. In conclusion, the low seroprevalence for T. gondii and N. caninum indicated low environmental and food risk for animal infection and the seronegativity for Leishmania spp. and T. cruzi may reflect the absence of these pathogens in urban areas of Curitiba. Moreover, neighborhood dogs may be used as environmental sentinels for the presence of protozoan pathogens and their vectors.

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

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B Bastrenta

2003-03-01

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

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

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

2016-01-01

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

Molecular screening of Leishmania spp. infection and bloodmeals in sandflies from a leishmaniasis focus in southwestern Turkey.

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Karaku Ş, M; Pekağ Irba Ş, M; Demir, S; Eren, H; Töz, S; Özbel, Y

2017-06-01

Leishmaniasis is an arthropod-borne disease that affects approximately 2 million people worldwide annually. The aims of this study were to detect the presence of Leishmania (Kinetoplastida: Trypanosomatidae) DNA and the feeding preferences of probable vector species in an endemic focus of Leishmania infantum in Turkey. Entomological sampling was performed in August and October 2015 in Aydın province, where cases of human and canine leishmaniasis have been reported previously. A total of 1059 sandfly specimens comprising nine species belonging to two genera, Phlebotomus and Sergentomyia (both: Diptera: Psychodidae), and five subgenera of the Phlebotomus genus (Phlebotomus, Paraphlebotomus, Larroussius, Adlerius and Transphlebotomus) were collected in five villages. Among all Phlebotomus specimens, Phlebotomus neglectus (39%) was noted as the most abundant species, followed by Phlebotomus tobbi (18%). Leishmania DNA was detected in pools from P. neglectus, P. tobbi and Sergentomyia dentata by kDNA polymerase chain reaction (PCR). Leishmania DNA from Phlebotomus specimens was identified as L. infantum, but Leishmania DNA from Sergentomyia spp. could not be identified to species level by ITS-1 real-time PCR. The detection of Leishmania DNA in wild-caught P. neglectus and the high percentage (24.2%) of human DNA in engorged specimens suggests that P. neglectus is probably an important vector species for L. infantum in Aydın province. © 2016 The Royal Entomological Society.

Leishmania hijacking of the macrophage intracellular compartments.

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Liévin-Le Moal, Vanessa; Loiseau, Philippe M

2016-02-01

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

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

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

2011-11-14

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

Epidemiologia das infecções hematogênicas por Candida spp

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Colombo Arnaldo Lopes

2003-01-01

Full Text Available O gênero Candida spp é responsável por cerca de 80% das infecções fúngicas no ambiente hospitalar e constitui causa relevante de infecções de corrente sanguínea. Nos Estados Unidos da América, Candida spp é a quarta causa mais comum de infecções de corrente sanguínea, respondendo por cerca de 8% dos casos das infecções documentadas neste sítio. Espécies não-albicans respondem hoje por ao menos 50% das infecções invasivas por Candida spp, apresentando peculiaridades de história natural e sensibilidade a antifúngicos. A mortalidade geral de fungemias por Candida spp é da ordem de 40 a 60%, tornado esta complicação infecciosa um grande desafio para os clínicos que trabalham em hospitais terciários em diferentes países.

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

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

2017-03-13

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

Infection by Leishmania spp. in Free-Ranging Opossums (Didelphis albiventris) in an Environmentally Protected Area Inhabited by Humans in Southeastern Brazil.

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Paiz, Laís Moraes; Donalisio, Maria Rita; Richini-Pereira, Virgínia Bodelão; Motoie, Gabriela; Castagna, Claudio Luiz; Tolezano, José Eduardo

2016-11-01

There is a growing concern about the participation of wild hosts and reservoirs in the epidemiology of leishmaniasis, particularly within the context of increasingly frequent environmental changes and the expansion of the One Health concept. This work is a molecular research of infection by Leishmania spp. among the wildlife of an environmentally protected area located in the municipality of Campinas, São Paulo, Brazil. The studied area has a history of intense environmental changes, with notifications of human cases of cutaneous leishmaniasis in the 1990s, and a focus of canine visceral leishmaniasis since 2009. Eighty-two wild mammals were sampled by monthly captures in this region over a 1-year period. Blood samples were collected from each animal and subjected to DNA extraction and PCR using primers for the region of the internal transcribed spacer-1. The results of gene sequencing for the first time revealed the infection of opossums (Didelphis albiventris) by Leishmania spp., subgenera Leishmania and Viannia, in Campinas. These findings, in addition to environmental and historical characteristics of the studied area, indicate a possible role of wildlife in the introduction and/or maintenance of natural foci of leishmaniasis transmission.

Spatial and simultaneous seroepidemiology of anti-Leishmania spp. antibodies in dog owners and their dogs from randomly selected households in a major city of southern Brazil.

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Benitez, Aline do Nascimento; Martins, Felippe Danyel Cardoso; Mareze, Marcelle; Nino, Beatriz de Souza Lima; Caldart, Eloiza Teles; Ferreira, Fernanda Pinto; Mitsuka-Breganó, Regina; Freire, Roberta Lemos; Galhardo, Juliana Arena; Martins, Camila Marinelli; Biondo, Alexander Welker; Navarro, Italmar Teodorico

2018-06-01

Although leishmaniasis has been described as a classic example of a zoonosis requiring a comprehensive approach for control, to date, no study has been conducted on the spatial distribution of simultaneous Leishmania spp. seroprevalence in dog owners and dogs from randomly selected households in urban settings. Accordingly, the present study aimed to simultaneously identify the seroprevalence, spatial distribution and associated factors of infection with Leishmania spp. in dog owners and their dogs in the city of Londrina, a county seat in southern Brazil with a population of half a million people and ranked 18th in population and 145th in the human development index (HDI) out of 5570 Brazilian cities. Overall, 564 households were surveyed and included 597 homeowners and their 729 dogs. Anti-Leishmania spp. antibodies were detected by ELISA in 9/597 (1.50%) dog owners and in 32/729 (4.38%) dogs, with significantly higher prevalence (p = 0.0042) in dogs. Spatial analysis revealed associations between seropositive dogs and households located up to 500 m from the local railway. No clusters were found for either owner or dog case distributions. In summary, the seroepidemiological and spatial results collectively show a lack of association of the factors for infection, and the results demonstrated higher exposure for dogs than their owners. However, railway areas may provide favorable conditions for the maintenance of infected phlebotomines, thereby causing infection in nearby domiciled dogs. In such an urban scenario, local sanitary barriers should be focused on the terrestrial routes of people and surrounding areas, particularly railways, via continuous vector surveillance and identification of phlebotomines infected by Leishmania spp. Copyright © 2018. Published by Elsevier B.V.

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

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

2017-02-01

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

Detection of Leishmania spp in silvatic mammals and isolation of Leishmania (Viannia braziliensis from Rattus rattus in an endemic area for leishmaniasis in Minas Gerais State, Brazil.

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Agnes Antônia Sampaio Pereira

Full Text Available Knowledge of potential reservoirs of Leishmania spp. in an anthropic environment is important so that surveillance and control measures can be implemented. The aim of this study was to investigate the infection by Leishmania in small mammals in an area located in Minas Gerais, Brazil, that undergoes changes in its natural environment and presents autochthonous human cases of cutaneous leishmaniasis (CL and visceral leishmaniasis (VL. For the capture of the animals, Sherman and Tomahawk traps were used and distributed in the peridomicile of houses with reports of autochthonous cases of CL or VL. Six catches were carried out on two consecutive nights with intervals of two months during one year and samples of spleen, liver, tail skin, ear skin and bone marrow of the animals were obtained. Parasitological and molecular methods were used to detect the infection. Identification of the Leishmania species was performed by PCR RFLPhsp70. Twenty five animals of four species were captured: ten Rattus rattus, nine Didelphis albiventris, five Cerradomys subflavus and one Marmosops incanus. In the PCR-hsp70, five animals were positive (20%. The Leishmania species identified in PCR-RFLPhsp70 were: Leishmania braziliensis in D. albiventris (2, C. subflavus (1 and R. rattus (1 and Leishmania infantum in R. rattus (1. The highest positivity rate for L. braziliensis was obtained in the liver samples. The spleen was the only tissue positive for L. infantum. It was isolated in culture medium L. braziliensis from two samples (liver and spleen of R. rattus. This is the first record of isolation of L. braziliensis from R. rattus in the southeastern region of Brazil. These results are relevant to the knowledge of the epidemiology of leishmaniasis in the region, mainly in the investigation of the presence of hosts and possible reservoirs of the parasite.

An Innovative Field-Applicable Molecular Test to Diagnose Cutaneous Leishmania Viannia spp. Infections.

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Omar A Saldarriaga

2016-04-01

Full Text Available Cutaneous and mucosal leishmaniasis is widely distributed in Central and South America. Leishmania of the Viannia subgenus are the most frequent species infecting humans. L. (V. braziliensis, L. (V. panamensis are also responsible for metastatic mucosal leishmaniasis. Conventional or real time PCR is a more sensitive diagnostic test than microscopy, but the cost and requirement for infrastructure and trained personnel makes it impractical in most endemic regions. Primary health systems need a sensitive and specific point of care (POC diagnostic tool. We developed a novel POC molecular diagnostic test for cutaneous leishmaniasis caused by Leishmania (Viannia spp. Parasite DNA was amplified using isothermal Recombinase Polymerase Amplification (RPA with primers and probes that targeted the kinetoplast DNA. The amplification product was detected by naked eye with a lateral flow (LF immunochromatographic strip. The RPA-LF had an analytical sensitivity equivalent to 0.1 parasites per reaction. The test amplified the principal L. Viannia species from multiple countries: L. (V. braziliensis (n = 33, L. (V. guyanensis (n = 17, L. (V. panamensis (n = 9. The less common L. (V. lainsoni, L. (V. shawi, and L. (V. naiffi were also amplified. No amplification was observed in parasites of the L. (Leishmania subgenus. In a small number of clinical samples (n = 13 we found 100% agreement between PCR and RPA-LF. The high analytical sensitivity and clinical validation indicate the test could improve the efficiency of diagnosis, especially in chronic lesions with submicroscopic parasite burdens. Field implementation of the RPA-LF test could contribute to management and control of cutaneous and mucosal leishmaniasis.

Validación de la PCR en la detección de parásitos de Leishmania (Viannia spp. en Lutzomyia (Diptera: Psychodidae como herramienta en la definición de especies vectores.

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Erika Santamaría

2005-06-01

Full Text Available lntroducción. En leishmaniasis se acepta que la reacción en cadena de la polimerasa (PCR ha simplificado el proceso de incriminación vectorial. Sin embargo, pocas veces se ha determinado la sensibilidad y la especificidad de cada PCR en la detección y la identificación del parasito en los flebótomos. Objetivo. Evaluar la aplicabilidad de la reacción en cadena de la polimerasa (PCR, basada en los iniciadores 81 y 82, en la detecci6n e identificación de parasitos de Leishmania (Viannia en insectos vectores enteros sin disecar. Metodología. Se determinó la sensibilidad y la especificidad de la PCR empleando diluciones de cultivo de parasitos de Leishmania spp. Se estableció el número máximo de hembras de Lutzomyia que pueden ser procesadas a la vez sin disminuir la sensibilidad de la PCR, procesando el ADN de grupos de una a cinco hembras de Lutzomyia en presencia del ADN de las diluciones de cultivo de parasitos. Además, se comparó en grupos de flebótomos infectados experimentalmente, la sensibilidad de esta PCR en la detección de infección por Leishmania (Viannia frente al método de busqueda de flagelados por disección del insecto y examen microscópico. Resultados. La PCR detectó desde un parasito de Leishmania (Viannia y permiti6 el procesamiento de hasta tres insectos enteros sin alterar la sensibilidad. Los porcentajes de infección experimental detectados con las dos tecnicas fueron similares, 33,3% con la PCR y 30% con el examen microscópico. Además, se confirmó que los iniciadores 81 y 82 son especificos para especies del subgenero Leishmania (Viannia. Conclusión. Los resultados obtenidos demuestran la sensibilidad y la especificidad de esta PCR y permiten recomendar su uso en la determinaci6n de infección natural con parasitos de Leishmania (Viannia en poblaciones silvestres de flebótomos.

Detection of different Leishmania spp. and Trypanosoma cruzi antibodies in cats from the Yucatan Peninsula (Mexico) using an iron superoxide dismutase excreted as antigen.

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Longoni, Silvia S; López-Cespedes, Angeles; Sánchez-Moreno, Manuel; Bolio-Gonzalez, Manuel E; Sauri-Arceo, Carlos H; Rodríguez-Vivas, Roger I; Marín, Clotilde

2012-09-01

Although human leishmaniasis has been reported in 20 states in Mexico, no case of leishmaniasis has been reported in cats to date. In the Yucatan Peninsula, it has been found that dogs may act as reservoirs for at least three Leishmania species (Leishmania mexicana, Leishmania braziliensis, and Leishmania panamensis). In this study we identified specific antibodies against these three Leishmania spp. and Trypanosoma cruzi in the sera from 95 cats from two States on the Yucatan Peninsula, namely Quintana Roo and Yucatan, by ELISA and Western blot techniques using whole extract and an iron superoxide dismutase excreted by the parasites as antigens. As well as demonstrating the presence of trypanosomatid antibodies in the feline population on the Yucatan Peninsula, we were also able to confirm the high sensitivity and specificity of the iron superoxide dismutase antigen secreted by them, which may prove to be very useful in epidemiological studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

PRESENCIA DE Wolbachia y Leishmania EN UNA POBLACION DE Lutzomyia evansi PRESENTE EN LA COSTA CARIBE DE COLOMBIA

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Rafael J. Vivero-Gómez

2016-07-01

Full Text Available Lutzomyia evansi es importante en salud pública por su participación en la trasmisión de la leishmaniasis visceral y cutánea en la costa caribe de Colombia. Diversos estudios se han desarrollado sobre la poblaciones naturales de Lutzomyia evansi, sin embargo pocos estudios han explorado en profundidad la detección de microorganismos simbióticos (ej. Wolbachia y de manera simultánea la presencia de Leishmania sp.. El endosimbionte Wolbachia ha sido propuesto en la actualidad como control biológico de insectos vectores de diversas enfermedades tropicales. En el presente estudio el ADN de tres especies del género Lutzomyia colectadas en el municipio de Ovejas (Departamento de Sucre fue evaluado para detectar la infección natural por la bacteria Wolbachia y la presencia de parásitos del género Leishmania. El ADN total de 176 individuos adultos y 34 inmaduros (larvas y pupas de Lu. evansi, fue utilizado para evaluar la detección de Wolbachia mediante amplificación por PCR del gen WSP (Proteína Mayor de la Superficie de Wolbachia y la infección por Leishmania mediante amplificación por PCR de segmentos de los genes HPSN70 (Proteína de Choque Térmico. Se encontró un grupo de machos infectado de forma natural por Wolbachia y nueve grupos de hembras con infección natural por Leishmania, todos pertenecientes a Lutzomyia evansi. El análisis filogenético de la secuencia del gen WSP de Wolbachia indica la ubicación de la cepa detectada dentro del supergrupo B (haplogrupo wLeva y su relación con haplotipos previamente reportados de Lutzomyia evansi y Lutzomya dubitans. Una región de 418 pb del gen HSP-70N fue secuenciada y mostró similaridad con secuencias de Leishmania luego de realizar el análisis en BlastN. Se confirma la presencia de Wolbachia en poblaciones silvestres de machos de L. evansi y la infección natural por Leishmania spp. en hembras de la misma especie cuya infección por Wolbachia resulto negativa.

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

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Tâmara Dias Oliveira Machado

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

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

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

2017-10-01

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

Presence of anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. and -Ehrlichia canis antibodies in free-ranging maned wolves (Chrysocyon brachyurus in the northeastern region of the state of São Paulo, Brazil

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Solange Oliveira

2016-09-01

Full Text Available O lobo-guará (Chrysocyon brachyurus habita o ecossistema de Cerrado e é considerado o maior canídeo da América do Sul e uma espécie ameaçada de extinção pela "International Union for Conservation of Nature" (IUNC. O objetivo desse estudo foi investigar a presença de anticorpos anti-Toxoplasma gondii, -Neospora caninum, -Leishmania spp. e -Ehrlichia canis em lobos-guará da região nordeste do estado de São Paulo, Brasil. Das 17 amostras de soro testadas por meio da reação de imunofluorescência indireta (RIFI, 88,2% (15/17, 17,6% (3/17 e 52,9% (9/17 apresentaram anticorpos anti-T. gondii, -Leishmania spp. e -E. canis, respectivamente. Todos os animais testados foram soronegativos para N. caninum. Esses resultados indicam a exposição dos lobos-guará dessa região aos agentes pesquisados. A presença de um complexo industrial, agricultura extensiva e fragmentação de habitat na região nordeste do estado de São Paulo, favorece a proximidade desses animais silvestres a ambientes urbanos o que pode contribuir para a transmissão de doenças entre os animais silvestres, domésticos e o homem.

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

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F. Vélez Bernal

2013-03-01

Full Text Available Algunas especies de Leishmania del subgénero Viannia, especialmente Leishmania braziliensis y Leishmania panamensis, pueden invadir la mucosa naso-orofaríngea al diseminarse por vía linfática y sanguínea a partir de una lesión cutánea y ocasionar lesiones en el tabique nasal, paladar blando, úvula, pilares amigdalinos, laringe, faringe, dorso nasal, labios y pómulos, que pueden conducir a la desfiguración. La mucosa más frecuentemente afectada es la del tabique nasal, principalmente en su parte anterior. La invasión de la mucosa puede ocurrir simultáneamente con lesiones cutáneas activas, aunque más frecuentemente aparecen 1 o 2 años después de la lesión en la piel; sin embargo, en el 16 % de los casos no hay antecedentes de lesiones cutáneas, lo que sugiere que con la picadura del insecto vector se produjo una infección primaria asintomática u oligosintomática y luego se produjo la diseminación del parasito a la mucosas. En este artículo presentamos 2 casos clínicos de leishmaniosis mucosa producidos por L. panamensis y los procedimientos quirúrgicos reconstructivos que se realizaron. Se hace además un recuento de los diagnósticos diferenciales en tejidos oronasales.Species of Leishmania of Viannia subgenus, mainly L. braziliensis and L. panamensis, may invade the nasooro-pharyngeal mucosal after spread from the skin lesion via lymph and blood, causing lesions in the nasal septum, soft palate, uvula, tonsillar pillars, larynx, pharynx, nasal dorsum, lips and cheeks. The mucosal membrane most frequently affected is the nasal septum, mainly in the anterior region. The invasion of mucosa may occur simultaneously with active skin lesions, but most often appear 1 or 2 years after the skin lesion; nevertheless, in 16 % of cases there is no history of skin lesions suggesting that the primary infection coursed with few symptoms and then was spread to mucosal membranes. In this article 2 cases of L panamensis mucosal

Leishmania infantum, Dirofilaria spp. and other endoparasite infections in kennel dogs in central Italy

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Sauda, Federica; Malandrucco, Livia; Macrì, Gladia; Scarpulla, Manuela; De Liberato, Claudio; Terracciano, Giuliana; Fichi, Gianluca; Berrilli, Federica; Perrucci, Stefania

2018-01-01

Prevalence and risk factors of Leishmania infantum, Dirofilaria spp. and other potentially zoonotic or canine-specific endoparasite infections were assessed in 639 kennel dogs from central Italy. To this end, individual blood and fecal samples were examined using parasitological, immunological and molecular techniques. The presence of compatible clinical pictures, as well as age and gender were considered as putative risks factors. To evaluate risk factors, multivariable analysis with logistic regression and univariable analysis with a Chi square test and a Fischer’s exact test were performed. Overall, 52.6% of dogs (95% CI 48.6-56.5) were found positive, while 39.6% of dogs (95% CI 35.8-43.5) were infected by potentially zoonotic species. Leishmania infantum and Dirofilaria repens showed prevalences of 2.5% (95% CI 1.5-4.1) and 2.8% (95% CI 1.7-4.5), respectively. The prevalence of cardiorespiratory parasites was 7.8% (95% CI 5.9-10.3) and included the species Angiostrongylus vasorum, Eucoleus aerophilus, Eucoleus boehmi and D. immitis; the latter showed a prevalence of 0.2% (95% CI 0.001-1). Intestinal parasites were significantly prevalent (38.8%, 95% CI 35-42.7) and they consisted mainly of species of major zoonotic concern, including ancylostomatids, Toxocara canis, Giardia duodenalis, Dipylidium caninum, Taeniidae, Strongyloides stercoralis and Cryptosporidium parvum. Endoparasites were significantly prevalent in clinically suspected dogs. Leishmania infantum and cardiorespiratory nematodes were prevalent in older dogs, while intestinal parasites were prevalent in younger dogs. Results show high dog and public health risks in kennels in central Italy, and suggest the need for more effective control measures. PMID:29388550

Leishmania infantum, Dirofilaria spp. and other endoparasite infections in kennel dogs in central Italy

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Sauda Federica

2018-01-01

Full Text Available Prevalence and risk factors of Leishmania infantum, Dirofilaria spp. and other potentially zoonotic or canine-specific endoparasite infections were assessed in 639 kennel dogs from central Italy. To this end, individual blood and fecal samples were examined using parasitological, immunological and molecular techniques. The presence of compatible clinical pictures, as well as age and gender were considered as putative risks factors. To evaluate risk factors, multivariable analysis with logistic regression and univariable analysis with a Chi square test and a Fischer’s exact test were performed. Overall, 52.6% of dogs (95% CI 48.6-56.5 were found positive, while 39.6% of dogs (95% CI 35.8-43.5 were infected by potentially zoonotic species. Leishmania infantum and Dirofilaria repens showed prevalences of 2.5% (95% CI 1.5-4.1 and 2.8% (95% CI 1.7-4.5, respectively. The prevalence of cardiorespiratory parasites was 7.8% (95% CI 5.9-10.3 and included the species Angiostrongylus vasorum, Eucoleus aerophilus, Eucoleus boehmi and D. immitis; the latter showed a prevalence of 0.2% (95% CI 0.001-1. Intestinal parasites were significantly prevalent (38.8%, 95% CI 35-42.7 and they consisted mainly of species of major zoonotic concern, including ancylostomatids, Toxocara canis, Giardia duodenalis, Dipylidium caninum, Taeniidae, Strongyloides stercoralis and Cryptosporidium parvum. Endoparasites were significantly prevalent in clinically suspected dogs. Leishmania infantum and cardiorespiratory nematodes were prevalent in older dogs, while intestinal parasites were prevalent in younger dogs. Results show high dog and public health risks in kennels in central Italy, and suggest the need for more effective control measures.

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

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

2017-01-01

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

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

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

2017-11-07

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

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

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

2012-07-01

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

Deception and Manipulation: The Arms of Leishmania, a Successful Parasite

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Cecílio, Pedro; Pérez-Cabezas, Begoña; Santarém, Nuno; Maciel, Joana; Rodrigues, Vasco; Cordeiro da Silva, Anabela

2014-01-01

Leishmania spp. are intracellular parasitic protozoa responsible for a group of neglected tropical diseases, endemic in 98 countries around the world, called leishmaniasis. These parasites have a complex digenetic life cycle requiring a susceptible vertebrate host and a permissive insect vector, which allow their transmission. The clinical manifestations associated with leishmaniasis depend on complex interactions between the parasite and the host immune system. Consequently, leishmaniasis can be manifested as a self-healing cutaneous affliction or a visceral pathology, being the last one fatal in 85–90% of untreated cases. As a result of a long host–parasite co-evolutionary process, Leishmania spp. developed different immunomodulatory strategies that are essential for the establishment of infection. Only through deception and manipulation of the immune system, Leishmania spp. can complete its life cycle and survive. The understanding of the mechanisms associated with immune evasion and disease progression is essential for the development of novel therapies and vaccine approaches. Here, we revise how the parasite manipulates cell death and immune responses to survive and thrive in the shadow of the immune system. PMID:25368612

Deception and Manipulation: the arms of Leishmania, a successful parasite

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Pedro eCecílio

2014-10-01

Full Text Available Leishmania spp. are intracellular parasitic protozoa responsible for a group of neglected tropical diseases, endemic in 98 countries around the world, called leishmaniasis. These parasites have a complex digenetic life cycle requiring a susceptible vertebrate host and a permissive insect vector, which allow their transmission. The clinical manifestations associated with leishmaniasis depend on complex interactions between the parasite and the host immune system. Consequently, leishmaniasis can be manifested as a self-healing cutaneous affliction or a visceral pathology, being the last one fatal in 85-90% of untreated cases. As a result of a long host-parasite co-evolutionary process, Leishmania spp. developed different immunomodulatory strategies that are essential for the establishment of infection. Only through deception and manipulation of the immune system, Leishmania spp. can complete its life cycle and survive. The understanding of the mechanisms associated with immune evasion and disease progression is essential for the development of novel therapies and vaccine approaches. Here, we revise how the parasite manipulates cell death and immune responses to survive and thrive in the shadow of the immune system.

Multiple brain abscesses due to Penicillium spp infection Abscessos cerebrais múltiplos causados por infecção por Penicillium spp

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Danilo Teixeira Noritomi

2005-06-01

Full Text Available We present a case of central nervous system (CNS infection by a member of the Penicillium genera in a HIV-negative man in Brazil. The patient was admitted complaining of loss of visual fields and speech disturbances. CT scan revealed multiple brain abscesses. Stereothacic biopsies revealed fungal infection and amphotericin B treatment begun with initial improvement. The patient died few days later as a consequence of massive gastrointestinal bleeding due to ruptured esophageal varices. The necropsy and final microbiologic analyses disclosed infection by Penicillium sp. There are thousands of fungal species of the Penicillium genera. Systemic penicilliosis is caused by the P. marneffei and was formerly a rare disease, but now is one of the most common opportunistic infection of AIDS patients in Southeast Asia. The clinical presentation usually involves the respiratory system and the skin, besides general symptoms like fever and weight loss. Penicillium spp infection caused by species other than P. marneffei normally cause only superficial or allergic disease but rare cases of invasive disease do occur. We report the fourth case of Penicillium spp CNS infection.Apresentamos um caso de infecção do sistema nervoso central (SNC por Penicillium spp em paciente do sexo masculino, HIV-negativo no Brasil. O paciente apresentou-se ao Serviço de Urgência do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo queixando-se de alteração visual e dificuldade na fala. Exames de neuroimagem mostraram lesões múltiplas, compatíveis com abscessos. A biópsia esterotáxica revelou infecção fúngica, iniciando-se o tratamento com anfotericina B com sucesso inicial. O paciente morreu poucos dias depois, vítima de uma hemorragia digestiva maciça devido a varizes de esôfago. A necropsia e a análise microbiológica final da biópsia cerebral revelaram infecção por Penicillium spp. Exixtem centenas de espécies de fungos do g

Definición de las condiciones de temperatura y almacenamiento adecuadas en la detección de ADN de Leishmania por PCR en flebotominos.

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Olga L. Cabrera

2002-09-01

Full Text Available Para estudios epidemiológicos y programas de control de las leishmaniasis es importante la determinación taxonómica del insecto vector y del agente etiológico causante de esta enfermedad. Por su eficacia y sensibilidad, la utilización de técnicas moleculares, como la reacción en cadena de la polimerasa (PCR ha permitido avances en entomología médica. La metodología tradicional usada para la búsqueda de infección en los flebótomos es un método dispendioso que requiere mucho tiempo y capacitación para emitir un diagnóstico acertado. En el presente trabajo se evaluaron las condiciones y prácticas adecuadas para el almacenamiento de flebótomos con el propósito de aplicar la PCR. Hembras de Lutzomyia longipalpis de la colonia del Instituto Nacional de Salud se infectaron experimentalmente con una cepa de Leishmania chagasi del valle alto del río Magdalena (Quipile, Cundinamarca. Los insectos infectados se preservaron en tres soluciones: etanol al 100%, etanol al 70% y en buffer Tris- EDTA (TE; submuestras de cada una se almacenaron a -80 °C, -20 °C y a temperatura ambiente. Para determinar los porcentajes de infección, algunas de las hembras se disecaron para buscar las formas flageladas al microscopio. La extracción del KADN se realizó con Chelex 100. Para la amplificación se utilizaron los iniciadores OL1 y OL2 de Leishmania con electroforesis en geles de agarosa al 1%. En cada una de las condiciones descritas se logró la amplificación de un fragmento de »120 pb, correspondiente a Leishmania spp. Estos resultados muestran la ventaja de incorporar como técnica de rutina la PCR para detectar flebótomos infectados de zonas endémicas de leishmaniasis visceral. Por costo-efectividad, se concluyó que las muestras entomológicas para estudios de incriminación vectorial utilizando la PCR, se pueden preservar a temperatura ambiente en etanol al 70%.

Could Phlebotomus mascittii play a role as a natural vector for Leishmania infantum? New data.

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Obwaller, Adelheid G; Karakus, Mehmet; Poeppl, Wolfgang; Töz, Seray; Özbel, Yusuf; Aspöck, Horst; Walochnik, Julia

2016-08-19

The occurrence of phlebotomine sand flies in Central Europe was questioned until they were recorded for the first time in Germany in 1999, and ten years later also in Austria. The aim of this study was to investigate sand flies collected in Austria for their carrier status of Leishmania spp. From 2012 to 2013 field studies were conducted in eastern Austria. Altogether, 22 individuals of sand flies were found, all morphologically identified as Phlebotomus (Transphlebotomus) mascittii Grassi, 1908. Twelve non-engorged female specimens with no visible remnants of a blood meal in their bodies were individually investigated for Leishmania spp. by ITS-1 real-time PCR. One out of these was positive for Leishmania, identified as Leishmania infantum by DNA sequencing. This finding suggests that L. infantum is not excreted by P. mascittii and possibly can establish an infection within P. mascittii. Interestingly, an asymptomatic dog living on the farm where this sand fly had been caught was also Leishmania-positive. This study provides new data on the suspected vector capacity of P. mascittii, being the northernmost sand fly species in Europe and in most central European regions the only sand fly species found. Proven vector capacity of P. mascittii for Leishmania spp. would be of significant medico-veterinary importance, not only with respect to expanding sand fly populations in Central Europe related to global warming, but also in the light of globalization and increasing movements of humans.

Xenodiagnostico con Lutzomyia youngi en casos venezolanos de leishmaniasis cutaned por Leishmania braziliensis Xenodiagnosis with Lutzomyia youngi in Venezuelan cases of cutaneous leishmaniais due to Leishmania braziliensis

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Elina Rojas

1989-03-01

Full Text Available Xenodiagnósticos con Lutzomya yungi aplicados en los bordes de las úlceras de pacientes infectados con Leishmania braziliensis antes y después del tratamiento con 10 dosis de antimonial pentavalente y un aminoglicósido, evidencian la condición reservoria de leishmanias del enfermo, para flebótomos endofágicos y la utilidad de un tratamiento específico-temprano que no solamente conduce a la curación clínica, sino a la eliminación del riesgo de una eventual transmisión intradomiciliar por insectos que pican dentro del domicilio durante la noche.Eight patients infected with Leishmania braziliensis were used for xenodiagnosis with Lutzomtyia youngi, before and after specific antileishmanial treatment with "glucantime" and "gabbromycin". All of them infected sandflies fed on the borders of the skin lesions before the treatment, suggesting that infected persons might act as reservoirs of infection for an indoor-bitting sandfly species. The negative results obtained by xenodiagnosis carried out after specific treatment of the same individuals indicated cure of the patients, and a reduction of risk for further intradomiciliary transmission.

Comportamiento experimental del Sporothrix schenckii y la Leishmania mexicana en el hamster Experimental behavior of Sporothrix schenckii and Leishmania mexicana in hamsters

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Luz Angela González de Polanía

1990-10-01

Full Text Available La descripción macroscópica del proceso de patogénesis en hamsters inoculados subcutáneamente en nariz con Sporothrix schenckii ó Leishmania mexicana spp. proporcionó bases para diferenciar estos dos microorganismos en un modelo animal utilizado comunmente para estudiarlos. Observaciones secuenciales durante 150 días permitieron afirmar que en las infecciones causadas por estos patógenos se presentaron edema y eritema como signos primarios, seguidos de alopecia, necrosis y ulceración. La producción de pus fué una característica distintiva para el S. schenckii. Estos signos clínicos se observaron más temprano en la esporotricosis que en la infección por L. mexicana, mostrando diferencias estadísticas significantes en días promedio de aparición. El presente trabajo muestra que las lesiones producidas tanto por el S. schenckii como la L. mexicana en este modelo experimental comparten signos clínicos, pero el tiempo de aparición de los mismos y su frecuencia relativa permiten diferenciarlas. Las condiciones de inoculación como: cepa de los microorganismos, dosis del inóculo, sitio y vía de inoculación, deben tenerse presentes en la evaluación de su comportamiento experimental.The macroscopic description of the pathogenic process of Sporothrix schenckii and Leishmania mexicana spp in hamsters inoculated subcutaneously in the nose provided bases for the differentiation of the behavior of these two microorganisms in a model frequently utilized for their study. Sequential observations over 150 days demonstrated that infections caused by these pathogens results initially in edema and erythema followed by loss of hair, necrosis and ulceration. The pus production was a characteristic presented only by S. schenckii. These clinical signs were observed earlier in sporotrichosis than in L. mexicana infection. Differences in the mean day of appearance were statistically significant. The lesions produced by S. schenckii and L. mexicana

Natural infection of bats with Leishmania in Ethiopia.

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

2015-10-01

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

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

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F. T. Silveira

1984-10-01

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

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

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

2017-10-02

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

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

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Camilo Andrés Morales

2014-09-01

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

Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures.

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Fernandes, Maria Cecilia; Dillon, Laura A L; Belew, Ashton Trey; Bravo, Hector Corrada; Mosser, David M; El-Sayed, Najib M

2016-05-10

Macrophages are mononuclear phagocytes that constitute a first line of defense against pathogens. While lethal to many microbes, they are the primary host cells of Leishmania spp. parasites, the obligate intracellular pathogens that cause leishmaniasis. We conducted transcriptomic profiling of two Leishmania species and the human macrophage over the course of intracellular infection by using high-throughput RNA sequencing to characterize the global gene expression changes and reprogramming events that underlie the interactions between the pathogen and its host. A systematic exclusion of the generic effects of large-particle phagocytosis revealed a vigorous, parasite-specific response of the human macrophage early in the infection that was greatly tempered at later time points. An analogous temporal expression pattern was observed with the parasite, suggesting that much of the reprogramming that occurs as parasites transform into intracellular forms generally stabilizes shortly after entry. Following that, the parasite establishes an intracellular niche within macrophages, with minimal communication between the parasite and the host cell later during the infection. No significant difference was observed between parasite species transcriptomes or in the transcriptional response of macrophages infected with each species. Our comparative analysis of gene expression changes that occur as mouse and human macrophages are infected by Leishmania spp. points toward a general signature of the Leishmania-macrophage infectome. Little is known about the transcriptional changes that occur within mammalian cells harboring intracellular pathogens. This study characterizes the gene expression signatures of Leishmania spp. parasites and the coordinated response of infected human macrophages as the pathogen enters and persists within them. After accounting for the generic effects of large-particle phagocytosis, we observed a parasite-specific response of the human macrophages early in

Effect of ionizing radiation on the morphology, physiology and growth of Leishmania ssp

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Bonetti, Franco C.; Spencer, Patrick J.; Nascimento, Nanci do; Junior A, Heitor F.

2000-01-01

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

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

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

2016-06-01

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

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

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

2013-01-01

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

Comparison of Tetrazolium Salt Assays for Evaluation of Drug Activity against Leishmania spp.

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Ginouves, Marine; Carme, Bernard; Couppie, Pierre

2014-01-01

In French Guiana, leishmaniasis is an essentially cutaneous infection. It constitutes a major public health problem, with a real incidence of 0.2 to 0.3%. Leishmania guyanensis is the causal species most frequently encountered in French Guiana. The treatment of leishmaniasis is essentially drug based, but the therapeutic compounds available have major side effects (e.g., liver damage and diabetes) and must be administered parenterally or are costly. The efficacy of some of these agents has declined due to the emergence of resistance in certain strains of Leishmania. There is currently no vaccine against leishmaniasis, and it is therefore both necessary and urgent to identify new compounds effective against Leishmania. The search for new drugs requires effective tests for evaluations of the leishmanicidal activity of a particular molecule or extract. Microculture tetrazolium assays (MTAs) are colorimetric tests based on the use of tetrazolium salts. We compared the efficacies of three tetrazolium salts—3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8)—for quantification of the promastigotes of various species of Leishmania. We found that the capacity of Leishmania to metabolize a tetrazolium salt depended on the salt used and the species of Leishmania. WST-8 was the tetrazolium salt best metabolized by L. guyanensis and gave the best sensitivity. PMID:24719447

Surveillance for antibodies to Leishmania spp. in dogs from Sri Lanka and India

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The global distribution of leishmaniasis is rapidly expanding into new geographic regions. Dogs are the primary reservoir hosts for human visceral leishmaniasis (VL) caused by infection with Leishmania infantum. Natural infections with other Leishmania species can occur in dogs, but their role as re...

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

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C. Vasconcellos

1999-07-01

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

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

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

2016-12-01

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

Susceptibilidad in vitro a infección por Leishmania y sensibilidad a medicamentos difiere según tipo de macrófagos The susceptibility to infection by Leishmania panamensis and the sensitivity to drugs differ according to the macrophage type

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Carol V. Mesa

2010-12-01

Full Text Available Introducción: Los sistemas in vitro son útiles en la evaluación de compuestos con actividad biológica, permitiendo por ejemplo, determinar el potencial citotóxico y leishmanicida de un compuesto. Objetivo: Identificar el tipo de célula mamífera que permita una óptima infección in vitro por Leishmania y que constituya el sistema adecuado para el tamizaje in vitro de compuestos con actividad anti-Leishmania. Métodos: La susceptibilidad de las células a infección por L. panamensis se evalúo según la Concentración Infectiva 50 determinada por microscopía de luz y citometría de flujo; la supervivencia intracelular de los amastigotes se evaluó por microscopía de fluorescencia y la sensibilidad de las células a anfotericina B y antimoniato de meglumina se evalúo por espectrofotometría. Resultados: Los cultivos primarios son más susceptibles a la infección por L. panamensis in vitro. Sin embargo, la supervivencia intracelular del parásito fue mejor en U-937. Por su parte, la sensibilidad de las células a anfotericina B y antimoniato de meglumina vario según el tipo de célula. Conclusión: Las células U-937 son las adecuadas para la infección por Leishmania porque: a presentan crecimiento ilimitado y se les puede inducir transformación a macrófagos. b la susceptibilidad a la infección por Leishmania es similar a la observada en cultivos primarios de macrófagos y c permiten mayor supervivencia de los amastigotes luego de la infección. Adicionalmente, las células U-937 son menos sensibles a la acción de los fármacos comúnmente utilizados como control en la detección de compuestos con actividad leishmanicida. Salud UIS 2010; 42: 200-211Introduction: In vitro systems are useful in the evaluation of compounds with biological activity determining the cytotoxic and leishmanicidal activity of the candidates. Objective: To identify the mammalian cell that allows the optimal in vitro infection by Leishmania and therefore

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

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Diana Sierra

2006-10-01

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

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

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

2010-01-01

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

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

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

2016-08-01

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

Leishmania (V.) braziliensis infecting bats from Pantanal wetland, Brazil: First records for Platyrrhinus lineatus and Artibeus planirostris.

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de Castro Ferreira, Eduardo; Pereira, Agnes Antônio Sampaio; Silveira, Maurício; Margonari, Carina; Marcon, Glaucia Elisete Barbosa; de Oliveira França, Adriana; Castro, Ludiele Souza; Bordignon, Marcelo Oscar; Fischer, Erich; Tomas, Walfrido Moraes; Dorval, Maria Elizabeth Cavalheiros; Gontijo, Célia Maria Ferreira

2017-08-01

In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments

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

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Nely Pinheiro Souza

2010-06-01

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

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

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Ana M Montalvo

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

Prevalência, avaliação clínica e imunológica de cães (Canis familiaris) (Linnaeus, 1758) naturalmente infectados por Leishmania (Leishmania) chagasi (Cunha & Chagas, 1937) provenientes do município de Tamandaré, região litoral Sul do Estado de Pernambuco, Brasil

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Marco Antônio Granja Barbosa

2009-01-01

A Leishmaniose Visceral Canina (LVC) no Brasil é causada por Leishmania (Leishmania) chagasi a qual é relatada em várias regiões. O objetivo desta pesquisa foi verificar a prevalência, analisar a correlação espacial entre a Leishmaniose Visceral Canina e fatores ambientais, avaliar e comparar os níveis de citocinas (IL-12, IFN-γ, IL-2 e IL-4) expressões por PCR em tempo real em diferentes tecidos/órgãos, determinar os padrões bio-químicos e hematológicos em cães naturalmente infectados p...

Naturally infected Lutzomyia sand flies in a Leishmania-endemic area of Brazil.

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Carvalho, Gustavo M L; Andrade Filho, Jose D; Falcao, Alda L; Rocha Lima, Ana C V M; Gontijo, Celia M F

2008-06-01

In Brazil, Leishmania transmission involves several species of phlebotomine sand flies that are closely associated with different parasites and reservoirs, giving rise to different transmission cycles. The present study focused on naturally infected phlebotomines originating from Santa Luzia, a municipality near Belo Horizonte, capital of the Brazilian state of Minas Gerais, in which leishmaniasis are endemic. Systematic and non systematic approaches,involving the use of light traps and direct aspiration from resting sites, respectively, were used to collect females and flies. Identification of the captured insects and determination of natural infection by Leishmania spp. were performed using both conventional dissection methods and polymerase chain reaction (PCR). The dissection of 102 sand flies allowed five species of Lutzomyia to be identified, although no flagellate parasite forms were observed.In addition, 211 sand flies were identified, were separated according to species, and were combined into 11 pools of up to 20 individuals each. PCR analyses showed that two of these pools were infected with Leishmania:one pool of Lu. whitmani was infected with Le. (Viannia) spp. and another of Lu. cortelezzii was infected with Le. chagasi. This suggests that Lu. whitmani may be a possible vector of Leishmania in the study area, and more work needs to be performed to assess the role of Lu. cortelezzii as a vector.

Niña con erucismo hemorrágico por Lonomia spp.: reporte de un caso

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Walter Peña-Vásquez

Full Text Available Los accidentes causados por las setas urticantes o venenosas de las orugas de lepidópteros, se conocen como erucismo. Estos accidentes se producen por el contacto accidental, especialmente por los niños, con las cerdas sobre el cuerpo del insecto, conectadas con glándulas venenosas. Los síntomas pueden ser locales o sistémicos, con presentaciones clínicas fatales. El accidente ocasionado por las orugas del género Lonomia spp. puede desencadenar síndromes hemorrágicos, constituyendo estos la forma más grave de erucismo. Se reporta el caso de una niña de 5 años, procedente del poblado de Villarondos, en la Amazonía del Perú, departamento de Huánuco, la cual incidentalmente se hinca con las cerdas de una oruga, cursando luego con anemia hemolítica, plaquetopenia y trastorno de la coagulación. El diagnóstico fue establecido por la anamnesis, cuadro clínico, exámenes de laboratorio y respuesta al suero antilonómico. Se discuten los aspectos clínicos, laboratoriales y terapéuticos de erucismo por Lonomia spp.

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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Cardoso, Andre Gustavo Tempone

1999-07-01

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

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

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

2017-10-10

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

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

International Nuclear Information System (INIS)

Cardoso, Andre Gustavo Tempone

1999-01-01

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

Detection of Leishmania spp. using parasitological, serological and molecular assays in asymptomatic and sick cats from an endemic area of visceral leishmaniosis in Brazil

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Maria Fernanda Alves-Martin

2017-11-01

Full Text Available Objective: To analyze the prevalence of feline leishmaniosis in 55 asymptomatic cats or assess clinical disease in a visceral leishmaniasis-endemic area using parasitological, serological and molecular techniques. Methods: Fifty-five adult domestic and non-purebred cats held at an animal shelter in a rural area of the municipality of Ilha Solteira, São Paulo, Brazil, a region endemic for canine visceral leishmaniosis, were evaluated. A total of 5 mL of blood was collected from each animal, for blood culture, serological (indirect fluorescent antibody test, soluble extract ELISA, ELISA recombinant K39 antigen and molecular tests (PCR. At the time of blood collection, the cats underwent clinical evaluation for the presence of clinical signs. Results: Flagellate protozoa were found in nine blood cultures (16.4%. Seropositivity by indirect fluorescent antibody test was observed in 32 serum samples (62.7%. ELISA-SE showed seropositivity in 37 cats (72.5%, while ELISA-rK39 revealed positive results in 11 cats (21.6%. Leishmania spp. was detected by PCR in whole blood samples from five cats (9.1%. Based on clinical evaluation, it was possible to detect the presence of clinical signs (alopecia, emaciation, pinna lesions, nose lesions, skin lesions in 30 animals (54.5%. Conclusions: To the knowledge of the authors, this is the first report of Leishmania spp. in domestic cats in the epidemiological cycle of leishmaniosis in the studied area, requiring more attention in the establishment of preventive steps to control this disease.

The proliferation potential of promastigotes of the main Leishmania species of the old world in NNN culture medium prepared using blood of four different mammals.

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Ladopoulos, Theodoros; Ntais, Pantelis; Tsirigotakis, Nikolaos; Dokianakis, Emmanouil; Antoniou, Maria

2015-10-01

The efficacy of the in vitro cultivation of promastigotes of four Leishmania spp. was tested in the biphasic Novy-MacNeal-Nicolle (NNN) medium prepared using blood from different animals (horse, donkey, goat and sheep). The aim was to test which NNN preparation gave the best yield in the shortest time for different parasite species, in order to obtain a large crop of promastigotes for experimental work and for antigen preparation. Promastigotes of Leishmania infantum, Leishmania donovani, Leishmania tropica and Leishmania major, the four main parasite species occurring in the old world, were defrosted from -80 °C and placed, at equal numbers, in the 4 different NNN preparations. At the end of the 7th day, the NNN medium using horse blood produced the greatest number of promastigotes for all Leishmania spp. tested, whilst goat blood proved the poorest medium, providing culture results only for L. infantum. This finding may be explained by the fact that Leishmania is a nicotinamide adenine dinucleotide (NAD) auxotroph and horse erythrocytes support NAD-dependent microorganisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Disseminated Leishmaniasis Caused by Leishmania Tropica in a Puppy from Karaj, Central Iran

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M Mohebali

2011-06-01

Full Text Available A 5-month old puppy with muco-cutaneous lesions in the chin, around lips and eyes was exam­ined physically and microscopically for leishmaniasis. Muco-cutaneous lesions containing a large num­ber of amastigotes of Leishmania spp. were observed. Amastigotes were also detected in liver and spleen of the puppy. The animal was positive with Dipstick rK39 kit and high level of anti-Leishmania antibodies was detected by direct agglutination test (DAT. DNA, Using PCR-RFLP technique extracted from cultured Leishmania promastigotes and L. tropica was identified. This is the first report of concurrent mucosal and visceral involvement of L. tropica in a puppy from Iran.

Leishmania major infection in a dog with cutaneous manifestations.

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Baneth, Gad; Nachum-Biala, Yaarit; Shabat Simon, Maytal; Brenner, Ori; Gaier, Sarit; Rojas, Alicia; Yasur-Landau, Daniel

2016-05-10

Leishmania major is a main cause of cutaneous leishmaniasis in humans in an area that stretches from India through Central Asia, the Middle East, to North and West Africa. In Israel, it is a common infection of humans with rodents as the reservoir hosts and Phlebotomus papatasi as its sand fly vector. A 6 months old spayed female mixed breed dog was referred to the Hebrew University Veterinary Teaching Hospital with a large ulcerative dermal lesion on the muzzle, and lesions in the foot pads and left hind leg. Histopathology of a skin biopsy found chronic lymphohistiocytic dermatitis with the presence of Leishmania spp. amastigotes in the muzzle. Physical examination indicated that the dog was overall in a good clinical condition and the main findings were the skin lesions and enlarged prescapular lymph nodes. Complete blood count and serum biochemistry profile were within reference ranges. Serology by ELISA was positive for Leishmania spp. and PCR of the prescapular lymph node was positive by an ITS1 region PCR-high resolution melt analysis. However, the melt curve and subsequent DNA sequencing indicated that infection was caused by L. major and not L. infantum, which is the main causative agent of canine leishmaniosis in the Mediterranean region. DNA was extracted from the paraffin embedded muzzle biopsy and PCR with sequencing also indicated L. major. The dog's young age and the absence of hyperglobulinemia and anemia were not typical of L. infantum infection. The dog was treated with allopurinol and the skin lesions improved and later disappeared when the dog was re-evaluated. This is the first molecularly-confirmed case of L. major infection in a dog. Two previous reports of L. major in dogs originated from Saudi-Arabia and Egypt in 1985 and 1987 were confirmed by enzymatic biochemical techniques. Serology for L. infantum was positive probably due to the well documented serological cross-reactivity between Leishmania spp. Although dogs and wild carnivores are

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

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

1999-01-01

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

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

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Jackson Maurício Lopes Costa

1990-12-01

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

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

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

2015-11-01

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

Infección de fibroblastos de piel de animales con distinto grado de susceptibilidad a Leishmania infantum y Leishmania mexicana (Kinetoplastida: Trypanosomatidae

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Miguel Angel Minero

2004-03-01

Full Text Available En este estudio se presenta un modelo in vitro de cultivo de fibroblastos de piel de hámster, ratón y rata hecho con el propósito de determinar diferencias en cuanto a la susceptibilidad a la infección por dos especies del género Leishmania (Kinetoplastida: Trypanosomatidae. Se realizó además un estudio ultraestructural por microscopía electrónica de transmisión con el fin de establecer si las formas intracelulares observadas correspondían a multiplicación interna o a fagocitosis múltiple. Se estudió la multiplicación de los parásitos en los fibroblastos de las tres especies de roedores infectados tanto por Leishmania infantum como por L. mexicana (cepa OCR y las diferencias entre las tres fueron estadísticamente significativas (pInfection and multiplication of Leishmania infantum and L. mexicana inside of skin fibroblasts from hamsters, mice and rats was achieved. This process was demonstrated either by counting parasites inside the stained cells or by electronic microscopy studies. In addition multiplication rate differences in the cells from these rodent species were determined, for L. infantum as well as for L. mexicana. Parasite development in hamsters and mice fibroblasts was evident but there was not multiplication in rat cells showing that apparently they are refractory to Leishmania infection. These results suggest that the parasite affinity for each animal, as well as any intracellular environment resistance, could involve genetic factors in the parasite multiplication. On the other hand, presence of amastigote multiplication inside of parasitophorus vacuole, showed by electronic microscopy images, probes a true parasite transformation. Therefore it is suggested that fibroblasts could work as host cells for parasite survival and permanency in the infected animals

Thrichomys laurentius (Rodentia; Echimyidae as a putative reservoir of Leishmania infantum and L. braziliensis: patterns of experimental infection.

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André Luiz Rodrigues Roque

Full Text Available The importance of the genus Thrichomys in the retention of infection and transmission of Leishmania species is supported by previous studies that describe an ancient interaction between caviomorphs and trypanosomatids and report the natural infection of Thrichomys spp. Moreover, these rodents are widely dispersed in Brazil and recognized as important hosts of other tripanosomatids. Our main purpose was to evaluate the putative role of Thrichomys laurentius in the retention of infection and amplification of the transmission cycle of Leishmania infantum and L. braziliensis. Male and female T. laurentius (n = 24 born in captivity were evaluated for the retention of infection with these Leishmania species and followed up by parasitological, serological, hematological, biochemical, histological, and molecular assays for 3, 6, 9, or 12 months post infection (mpi. T. laurentius showed its competence as maintenance host for the two inoculated Leishmania species. Four aspects should be highlighted: (i re-isolation of parasites 12 mpi; (ii the low parasitic burden displayed by T. laurentius tissues; (iii the early onset and maintenance of humoral response, and (iv the similar pattern of infection by the two Leishmania species. Both Leishmania species demonstrated the ability to invade and maintain itself in viscera and skin of T. laurentius, and no rodent displayed any lesion, histological changes, or clinical evidence of infection. We also wish to point out the irrelevance of the adjective dermotropic or viscerotropic to qualify L. braziliensis and L. infantum, respectively, when these species are hosted by nonhuman hosts. Our data suggest that T. laurentius may act at least as a maintenance host of both tested Leishmania species since it maintained long-lasting infections. Moreover, it cannot be discarded that Leishmania spp. infection in free-ranging T. laurentius could result in higher parasite burden due the more stressing conditions in the wild

Excreción de promastigotos de Leishmania pifanoi por Lutzomyia youngi experimentalmente infectada

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Elina Rojas

1995-12-01

Full Text Available Se describe el desarrollo poblacional promastigótico de Leishmania pifanoi en Lutzomyia youngi experimentalmente infectada y mantenida con sacarosa al 50% bajo condiciones constantes de temperatura y humedad. Se reconocen dos etapas para la diferenciación y el crecimiento de los parásitos entre las dos y ciento veinte horas postprandiales. Hasta 48 horas tiene lugar la diferenciación pleomórfica de amastigotos en promastigotos cortos, que se multiplican por división binaria hasta las 60 horas, cuando ocurre la ruptura de la membrana peritrófica. La segunda etapa tiene lugar entre las 72 y 96 horas cuando algunos parásitos migran hacia la válvula esofágica y los demás parásitos libres son excretados en gotitas fecales como promastigotos grandes y activos. Las primeras gotitas excretadas dan reacción positiva a glucosa o contienen cristales de urato. El exceso de promastigotos de la segunda fase de desarrollo es eliminado en las últimas excretas que dan reacción positiva con las pruebas Hemoscreen y Biuret para proteínas totales y también para glucosa, y constituyen el 82% del total de gotas excretadas. La excreción de parásitos por Lu. youngi es fase normal del desarrollo de L. pifanoi en un vector.

Excreción de promastigotos de Leishmania pifanoi por Lutzomyia youngi experimentalmente infectada

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Rojas Elina

1995-01-01

Full Text Available Se describe el desarrollo poblacional promastigótico de Leishmania pifanoi en Lutzomyia youngi experimentalmente infectada y mantenida con sacarosa al 50% bajo condiciones constantes de temperatura y humedad. Se reconocen dos etapas para la diferenciación y el crecimiento de los parásitos entre las dos y ciento veinte horas postprandiales. Hasta 48 horas tiene lugar la diferenciación pleomórfica de amastigotos en promastigotos cortos, que se multiplican por división binaria hasta las 60 horas, cuando ocurre la ruptura de la membrana peritrófica. La segunda etapa tiene lugar entre las 72 y 96 horas cuando algunos parásitos migran hacia la válvula esofágica y los demás parásitos libres son excretados en gotitas fecales como promastigotos grandes y activos. Las primeras gotitas excretadas dan reacción positiva a glucosa o contienen cristales de urato. El exceso de promastigotos de la segunda fase de desarrollo es eliminado en las últimas excretas que dan reacción positiva con las pruebas Hemoscreen y Biuret para proteínas totales y también para glucosa, y constituyen el 82% del total de gotas excretadas. La excreción de parásitos por Lu. youngi es fase normal del desarrollo de L. pifanoi en un vector.

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

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MICHALSKY Érika M.

2002-01-01

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

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

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

2007-01-01

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

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

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Ana Lugo Yarbuh

1982-12-01

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

El "Status" taxonomico de leishmania garnhami, indicado por su patron de desarrollo en el Vector The taxonomic status of Leishmania garnhami, indicated by its development pattern in the vector

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N. Añez

1985-03-01

Full Text Available Bajo condiciones experimentales, se estabelece el de desarrollo primario de Leishmania garnhami em su vector Lutzomyia townsendi, siguiendo disecciones diarias entre el Iro y 12mo dia post-imnfección. Se demuestra que L. garnhami puede lograr el estabelecimiento inicial de la infección en cualquiera de las regiones del intestino y en los túbulos de Malpighi del insecto vector. Un comportamiento similar fue observado en ejemplares de Lu. longipalpis. Se discute la susceptibilidad de Lu. townsendi a las infecciones por L. mexicana, L. braziliensis y L. garnhami. Se concluye que L. garnhami, a juzgar por su comportamiento en el vector, debe considerarse distinta a las especies del complejo L.mexicana y que su patrón de desarrollo difiere del de las especies de la Sección Suprapylaria, ya que invaden el triângulo pilórico, y del de la Peripylaria por su invasión a los túbulos de Malpighi.Under experimental conditions, the developmental pattern of Leishmania garnhami in its vector Lutzomyia townsendi, was established following daily dissections between the 1st and the 12th day post-infection. L. garnhami succeeded in establishing initial infections in any of the gut regions and in the Malpighian tubules of infected sandflies. Similar behavior was observed in infected Lu. longipalpis. The distribution of L. garnhami in the digestive tract of infected flies, is different to that observed in species of the L. mexicana and L. braziliensis complexes. The susceptibility of Lu. townsendi to infection by L. mexicana, L. braziliensis and L. garnhami is discussed. It is concluded that L. garnhami, according to its behaviour in the vector, must be considered different from the l. mexicana complex, and that its developmental pattern differs from that of the Suprapylaria, because it invades the hind triangle and also from the species of the Peripylaria by its invasion of the Malpighian tubules.

Intoxicação natural por Brachiaria spp. em ovinos no Brasil Central Brachiaria spp. poisoning in sheep in Central Brazil

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Vanessa S. Mustafa

2012-12-01

Full Text Available Brachiaria spp. é a principal forrageira utilizada para ruminantes no Brasil Central, mas a sua toxicidade, devida à presença de saponinas esteroidais, torna-se um importante entrave à sua utilização. Neste trabalho descrevem-se 34 surtos e um foco de intoxicação por Brachiaria spp em ovinos, que ocorreram em diferentes épocas do ano. A morbidade geral foi de 23,2% e a letalidade foi 88,3%. O tempo que os animais permaneceram no pasto até o surgimento dos sinais clínicos da intoxicação por Brachiaria spp. variou de 15 dias até mais de 12 meses. Em 90,1% dos surtos os animais eram menores de 12 meses de idade. O curso clínico da intoxicação variou de 2 a 45 dias. Os sinais clínicos e as lesões macroscópicas foram características de fotossenssibilização hepatógena, no entanto, nos casos mais agudos não foram observadas dermatite nem icterícia, ocorrendo severo edema em face e orelhas. Na histologia do fígado as lesões mais características foram a presença de macrófagos com citoplasma espumoso, encontrados principalmente nos sinusoides hepáticos e, às vezes, com imagens negativas de cristais acutiformes no citoplasma. Em oito das 11 fazendas visitadas os surtos ocorreram em pastagens de Brachiaria decumbens; em duas em pastagens de B. brizantha e uma em pastagem de B. decumbens, B. humidicola e Andropogon sp. As concentrações de saponinas nas pastagens, em 5 surtos, variou de 0.3% a 2.56%. As informações geradas neste trabalho permitem a proposta de medidas para controle e profilaxia da intoxicação por Brachiaria spp. no Brasil Central.Brachiaria spp. is the main pasture for ruminants in Central-Brazil, but the crucial problem for their utilization is the toxicity due to the presence of steroidal saponins. This paper reports 35 outbreaks of poisoning by Brachiaria spp in sheep. The poisoning occurred in different seasons of the year. Mean morbidity was 23.2% and mean lethality was 88.3%. The occurrence of

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

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

2007-01-01

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

Risk of Infection with Leishmania spp. in the Canine Population in the Netherlands

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Slappendel RJ

2002-12-01

Full Text Available The dog is the main reservoir of Leishmania infantum, the causative agent of visceral leishmaniasis (VL in humans in Southern Europe. In order to identify the risk of dogs from a Leishmania non-endemic area traveling to a Leishmania-endemic area becoming infected and the risk of transmitting infection to humans in non-endemic areas an investigation was performed, in which the results of a questionnaire were combined with the results of a serologic survey. The questionnaire was sent to 1478 at random chosen families in the Netherlands. Of the 59.0% responders 28.0% had one or more dogs and 4.8% of these dogs had visited Southern Europe during the summer period of that year. On a total population of 1,200,000 dogs in the Netherlands, this means that each year some 58,000 dogs are at risk of being exposed to a Leishmania infection in Southern Europe. During the period 1990–1992 blood was collected for serology in 1911 dogs presented to the Utrecht University Clinic because of clinical problems not related to leishmaniasis, of which 434 had been in Southern Europe in the foregoing years. None was serologically positive. From these data it can be deduced that the highest chance to obtain leishmaniasis during a vacation in Southern Europe is mathematically less than 1/434 or less than 0.23%. Serology was also performed during the period 1989–1993 in 597 dogs that had been in Southern Europe and were suspected of leishmaniasis. Titers were positive in 145 of these samples. Sixty-four of these dogs were born in the Mediterranean and had been imported into the Netherlands. Excluding these imported dogs, it was calculated that at least 0.027% of the 58,000 dogs yearly taken to Southern Europe during holidays become infected with Leishmania. In order to establish the risk of disease transmission for people in close contact with an infected dog, serum samples of owners and house mates of 37 dogs with leishmaniasis were tested. All 112 sera tested

Infection by Mycoplasma spp., feline immunodeficiency virus and feline leukemia virus in cats from an area endemic for visceral leishmaniasis.

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Marcondes, Mary; Hirata, Karina Y; Vides, Juliana P; Sobrinho, Ludmila S V; Azevedo, Jaqueline S; Vieira, Thállitha S W J; Vieira, Rafael F C

2018-03-20

Visceral leishmaniasis (VL) has been increasingly recognized in cats living in areas endemic for the disease. Co-infection with Leishmania infantum and other infectious agents is well established in dogs. However, for cats, data on co-infections with L. infantum and other infectious agents are still sparse. The aim of this study was to identify the prevalence of vector-borne pathogens, Mycoplasma spp., feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) in cats from an area endemic for VL in southeastern Brazil. Of the 90 cats, eight (8.9%) were infected with Mycoplasma spp., five (5.5%) were FIV- positive and one (1.1%) was FeLV-positive. Co-infection with L. infantum and at least one other infectious agent was found in 9/50 (18.0%; CI: 8.6-31.4%) cats. In Group 1 (cats infected naturally by L. infantum), 4/50 (8.0%) cats were positive for FIV, 4/50 (8%) for Mycoplasma spp. and 1/50 (2.0%) was co-infected with FeLV and Mycoplasma spp. In Group 2 (cats non-infected with L. infantum), 2/40 (5.0%) cats were infected with Mycoplasma spp. and 1/40 (2.5%) was co-infected with FIV and Mycoplasma spp. All cats were negative for Ehrlichia spp., Babesia spp. and Anaplasma platys. A low prevalence of co-infection in Leishmania-infected and non-infected cats was found. Co-infections with Leishmania and vector-borne diseases in cats are not common in this area endemic for VL in Brazil.

Diseño y evaluación de tres oligonucleótidos para la detección de Leishmania por PCR

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Omar Cáceres Rey

2002-07-01

Full Text Available La leishmaniasis afecta la salud pública en 88 países del mundo y representa un serio obstáculo para su desarrollo socioeconómico. Los métodos para diagnosticar la enfermedad toman tiempo y muchas veces son traumáticos para el paciente. Objetivo: Se aplicó PCR como método alternativo para el diagnóstico rápido de esta enfermedad. Materiales y métodos: A diferentes especies de Leishmania se les extrajo ADN genómico. Se diseñaron tres oligonucleótidos (LEISH 1, LEISH 2 y LEISH 3 dirigidos al extremo carboxilo terminal de la histona H2B de Leishmania (V. peruviana cuya secuencia parcial sirvió para diseñar dichos oligos, los cuales fueron probados en un sistema de PCR. Resultados: Los oligonucleótidos amplificaron exitosamente regiones de 123 pb (LEISH 1 / LEISH 2 y 139 pb (LEISH 1 / LEISH 3 de esta secuencia parcial utilizada. La sensibilidad del PCR fue de hasta 1 fg de ADN purificado de L. (V. peruviana y de 2 parásitos cuando se realizó la técnica de manera directa. La especificidad fue 100% (solo reconoció a Leishmania y no a Trypanosoma ni a humano. Los oligonucleótidos diseñados también amplificaron todas las especies de Leishmania evaluadas. Conclusión: El sistema de PCR diseñado puede ser aplicado en la detección del parásito a partir de cualquier tipo de muestra convirtiéndose en un método alternativo de diagnóstico de la enfermedad por su rapidez, especificidad y sensibilidad.

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

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

2018-02-20

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

Classificação de lâminas de madeira de Pinus spp. contaminadas por fungos manchadores

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Carneiro,Mayara Elita; Magalhães,Washington Luiz Esteves; Silvana,Nisgoski; Muñiz,Graciela Inês Bolzon

2013-01-01

A busca por novas tecnologias que garantam a uniformidade da qualidade dos produtos tem se tornado constante, assim este trabalho teve como objetivo estudar a potencialidade de medidas espectroscópicas combinadas a ferramentas estatísticas para classificação de lâminas de madeiras de Pinus spp. contaminadas por fungos manchadores. As amostras foram coletadas em processo industrial, e observou-se que algumas lâminas estavam contaminadas por fungos manchadores. Assim, utilizou-se este material ...

Estudio ultraestructural de la fagocitosis de promastigotes y amastigotes de Leishmania mexicana por la línea de células dendríticas FSDC

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Ladys Sarmiento; Martha Ayala; Sandra Peña; Gerzaín Rodríguez; Zelandia Fermín; Felix J. Tapia

2006-01-01

Introducción. Las células dendríticas están presentes en la mayoría de los tejidos, ellas capturany presentan antígenos para activar a los linfocitos T. Objetivo. Se describe ultraestructuralmente la fagocitosis de Leishmania mexicana por lalínea de células dendríticas FSDC, una línea de células de Langerhans obtenida de la epidermisfetal de ratón, e inmortalizada por la transducción retroviral del oncogen v-myc. Materiales y métodos. Se obtuvieron amastigotes de la lesión de ratones ...

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

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Willian Marinho Dourado Coelho

2010-12-01

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

PCR para la confirmación de transmisión experimental de Leishmania chagasi a hámster sano por picadura de Lutzomyia longipalpis (Diptera: Psychodidae.

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Olga L. Cabrera

2003-06-01

Full Text Available Se evaluó la efectividad de la PCR como herramienta en la detección de la transmisión experimental de Leishmania chagasi a hámster, Mesocricetus auratus, por picadura del insecto vector. Dos pares de hámsteres sanos y anestesiados fueron colocados en jaulas que contenían hembras de Lutzomyia longipalpis. Previamente, las hembras se infectaron experimentalmente con Leishmania chagasi y la infección se confirmó por disección en una submuestra. A los 37 y 51 días después de la exposición a los insectos infectados, las biopsias de hígado y bazo de cada hámster se sometieron a examen directo al microscopio, histopatología y PCR. El ADN se extrajo con Chelex 100®; en la amplificación se utilizó un par de iniciadores específicos para la región conservada de los minicírculos del ADN de Leishmania. El producto amplificado se separó en geles de agarosa y se visualizó bajo luz UV. En tres de las cuatro biopsias se observó una banda de 120 pares de bases, aproximadamente, correspondiente al tamaño esperado de la fracción del minicírculo. La técnica de PCR fue el único método que detectó la presencia del parásito. Estos resultados demostraron que la sensibilidad de la PCR acelera los procesos de incriminación vectorial de las especies vectoras de leishmaniasis.

Phlebotomus sergenti in a Cutaneous Leishmaniasis Focus in Azilal Province (High Atlas, Morocco): Molecular Detection and Genotyping of Leishmania tropica, and Feeding Behavior

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Ajaoud, Malika; Es-Sette, Nargys; Charrel, Rémi N; Laamrani-Idrissi, Abderahmane; Nhammi, Haddou; Riyad, Myriam; Lemrani, Meryem

2015-01-01

Background Phlebotomus (Paraphlebotomus) sergenti is at least one of the confirmed vectors for the transmission of cutaneous leishmaniasis caused by Leishmania tropica and distributed widely in Morocco. This form of leishmaniasis is considered largely as anthroponotic, although dogs were found infected with Leishmania tropica, suggestive of zoonosis in some rural areas. Methodology and Findings This survey aimed at (i) studying the presence of Leishmania in field caught Phlebotomus sergenti, (ii) investigating genetic diversity within Leishmania tropica and (iii) identifying the host-blood feeding preferences of Phlebotomus sergenti. A total of 4,407 sand flies were collected in three rural areas of Azilal province, using CDC miniature light traps. Samples collected were found to consist of 13 species: Phlebotomus spp. and 3 Sergentomyia spp. The most abundant species was Phlebotomus sergenti, accounting for 45.75 % of the total. 965 female Phlebotomus sergenti were screened for the presence of Leishmania by ITS1-PCR-RFLP, giving a positive rate of 5.7% (55/965), all being identified as Leishmania tropica. Nucleotide heterogeneity of PCR-amplified ITS1-5.8S rRNA gene-ITS2 was noted. Analyses of 31 sequences obtained segregated them into 16 haplotypes, of which 7 contain superimposed peaks at certain nucleotide positions, suggestive of heterozygosity. Phlebotomus sergenti collected were found to feed on a large variety of vertebrate hosts, as determined by Cytochrome b sequencing of the DNA from the blood meals of 64 engorged females. Conclusion Our findings supported the notion that Phlebotomus sergenti is the primary vector of Leishmania tropica in this focus, and that the latter is genetically very heterogeneous. Furthermore, our results might be suggestive of a certain level of heterozygosity in Leishmania tropica population. This finding, as well as the feeding of the vectors on different animals are of interest for further investigation. PMID:25826399

Phlebotomus sergenti in a cutaneous leishmaniasis focus in Azilal province (High Atlas, Morocco: molecular detection and genotyping of Leishmania tropica, and feeding behavior.

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Malika Ajaoud

2015-03-01

Full Text Available Phlebotomus (Paraphlebotomus sergenti is at least one of the confirmed vectors for the transmission of cutaneous leishmaniasis caused by Leishmania tropica and distributed widely in Morocco. This form of leishmaniasis is considered largely as anthroponotic, although dogs were found infected with Leishmania tropica, suggestive of zoonosis in some rural areas.This survey aimed at (i studying the presence of Leishmania in field caught Phlebotomus sergenti, (ii investigating genetic diversity within Leishmania tropica and (iii identifying the host-blood feeding preferences of Phlebotomus sergenti. A total of 4,407 sand flies were collected in three rural areas of Azilal province, using CDC miniature light traps. Samples collected were found to consist of 13 species: Phlebotomus spp. and 3 Sergentomyia spp. The most abundant species was Phlebotomus sergenti, accounting for 45.75 % of the total. 965 female Phlebotomus sergenti were screened for the presence of Leishmania by ITS1-PCR-RFLP, giving a positive rate of 5.7% (55/965, all being identified as Leishmania tropica. Nucleotide heterogeneity of PCR-amplified ITS1-5.8S rRNA gene-ITS2 was noted. Analyses of 31 sequences obtained segregated them into 16 haplotypes, of which 7 contain superimposed peaks at certain nucleotide positions, suggestive of heterozygosity. Phlebotomus sergenti collected were found to feed on a large variety of vertebrate hosts, as determined by Cytochrome b sequencing of the DNA from the blood meals of 64 engorged females.Our findings supported the notion that Phlebotomus sergenti is the primary vector of Leishmania tropica in this focus, and that the latter is genetically very heterogeneous. Furthermore, our results might be suggestive of a certain level of heterozygosity in Leishmania tropica population. This finding, as well as the feeding of the vectors on different animals are of interest for further investigation.

CONTAMINAÇÃO AMBIENTAL POR OVOS DE Ancylostoma spp. E Toxocara spp. EM ÁREAS DE SEIS PRAÇAS PÚBLICAS DO MUNICÍPIO DE VALENÇA, ESTADO DO RIO DE JANEIRO

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Filipe Souza de Lima e CIRNE

2017-07-01

Full Text Available A contaminação de praças públicas por ovos de geohelmintos constitui um problema de saúde pública. Nesses locais, ovos ou larvas podem permanecer por muito tempo, até que a infecção ocorra. O objetivo deste trabalho foi verificar a contaminação ambiental por ovos de Ancylostoma spp. e Toxocara spp. em amostras de solos coletadas de praças públicas de Valença, Rio de Janeiro. O trabalho englobou seis praças próximas ao centro da cidade. Foram colhidos 50g de solo de cinco pontos diferentes de cada praça, totalizando-se 30 amostras. Utilizou-se as técnicas de centrífugo-flutuaçãoem solução saturada de açúcar e de Hoffman. A contaminação somente por ovos de Ancylostoma spp. foi de 66,6% (4/6, sendo encontrados ovos em 30% (9/30 das amostras de solo analisadas. A ocorrência de ovos de Ancylostoma spp. nas praças públicas de Valença enfatiza a importância da adoção de medidas restritivas rígidas que impeçam a entrada de animais em locais de recreação para crianças, pois não apenas este, mas outros parasitas são capazes de comprometer a saúde humana e atuar como forma de infecção no ambiente para outros animais. 

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

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Maria Elizabeth Cavalheiros Dorval

2010-10-01

: 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.

Classificação de lâminas de madeira de Pinus spp. contaminadas por fungos manchadores Classification of Pinus spp. veneers wood contaminated by blue stain fungi

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Mayara Elita Carneiro; Washington Luiz Esteves Magalhães; Nisgoski Silvana; Graciela Inês Bolzon Muñiz

2013-01-01

A busca por novas tecnologias que garantam a uniformidade da qualidade dos produtos tem se tornado constante, assim este trabalho teve como objetivo estudar a potencialidade de medidas espectroscópicas combinadas a ferramentas estatísticas para classificação de lâminas de madeiras de Pinus spp. contaminadas por fungos manchadores. As amostras foram coletadas em processo industrial, e observou-se que algumas lâminas estavam contaminadas por fungos manchadores. Assim, utilizou-se este material ...

Riesgo de transmisión de Leishmania (Kinetoplastida: Trypanosomatidae en Mérida Venezuela

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Elsa Nieves

2014-09-01

Full Text Available La leishmaniasis es una enfermedad causada por la infección de un parásito protozoario del género Leishmania, transmitido por la picada de insectos hematófagos conocidos como flebotominos. El estudio tiene como objetivo determinar la presencia de flebotominos en los Distritos Sanitarios del estado Mérida y diseñar un mapa de riesgo de transmisión entomológico. Se utilizaron cuatro métodos de captura de flebotominos, los ejemplares se identificaron y se les determinó la infección natural por Leishmania. Se estimó la riqueza de especies, y se realizó un proceso analítico Jerárquico. Los resultados muestran la presencia de diversas especies de flebotominos en los Distritos Sanitarios del estado Mérida, siendo las especies de mayor frecuencia L. youngi, L. gomezi, L. ovallesi y L. walkeri. Se detectó 2,1% de infección natural con Leishmania, la cual se encontró en las 4 especies más frecuentes. Se presenta un mapa de riesgo de transmisión entomológico para el estado Mérida. El conocimiento de la situación actual de los vectores de Leishmania en el estado Mérida y el riesgo de transmisión son relevantes a la hora de considerar la prevención y posible surgimiento de nuevos brotes de leishmaniasis. Abstract (english The leishmaniasis is a disease caused by infection with a protozoan parasite of the genus Leishmania, transmitted by the bite of blood-sucking insects known as sandflies. The study aims to determine the presence of sandflies in Merida state health districts and design a map of entomological risk of transmission. Four methods capture sandflies were used, the specimens were identified and natural Leishmania infection was determined. The richness species was estimated and analityc Hierarchie procesess was performed. The results show the presence of various species of sandflies in Merida state health districts, L. youngi, L. gomezi, L. ovallesi and L. walkeri were most abundant species. The 2.1% of natural infection

Hepatozoon canis and Leishmania spp. coinfection in dogs diagnosed with visceral leishmaniasis.

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Morgado, Fernanda Nazaré; Cavalcanti, Amanda Dos Santos; Miranda, Luisa Helena de; O'Dwyer, Lúcia Helena; Silva, Maria Regina Lucas da; Menezes, Rodrigo Caldas; Andrade da Silva, Aurea Virgínia; Boité, Mariana Côrtes; Cupolillo, Elisa; Porrozzi, Renato

2016-01-01

This study describes the occurrence of dogs naturally co-infected with Hepatozoon canis and two Leishmania species: L. infantum or L. braziliensis. Four dogs serologically diagnosed with Visceral Leishmaniasis were euthanized. Liver and spleen samples were collected for histopathological analysis and DNA isolation. H. canis meronts were observed in tissues from all four dogs. H. canis infection was confirmed by PCR followed by sequencing of a fragment of 18S rRNA gene. Leishmania detection and typing was confirmed by ITS1' PCR-RFLP and parasite burden was calculated using ssrRNA quantitative qPCR. A DPP - Dual Path platform test was performed. One out (Dog #2) of four animals was asymptomatic. Dogs #1 and #4 were infected by L. infantum and were DPP test positive. Dogs #2 and #3 were infected by L. braziliensis and were DPP test negative. Furthermore, visceral dissemination was observed in Dogs #2 and #3, since L. braziliensis was detected in liver and spleen samples. The visceral dissemination of L. braziliensis associated with systemic signs suggested that this co-infection could influence the parasite burden and disease progression.

Polymerase chain reaction-based method for the identification of Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in mucosal tissues conserved in paraffin.

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Prestes, Suzane Ribeiro; Guerra, Jorge Augusto de Oliveira; Romero, Gustavo Adolfo Sierra; Magalhaes, Laylah Kelre Costa; Santana, Rosa Amelia Gonçalves; Maciel, Marcel Gonçalves; Custódio, Ana; Barbosa, Maria das Graças Vale; Silveira, Henrique

2015-01-01

In the Americas, mucosal leishmaniasis is primarily associated with infection by Leishmania (Viannia) braziliensis. However, Leishmania (Viannia) guyanensis is another important cause of this disease in the Brazilian Amazon. In this study, we aimed at detecting Leishmaniadeoxyribonucleic acid (DNA) within paraffin-embedded fragments of mucosal tissues, and characterizing the infecting parasite species. We evaluated samples collected from 114 patients treated at a reference center in the Brazilian Amazon by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses. Direct examination of biopsy imprints detected parasites in 10 of the 114 samples, while evaluation of hematoxylin and eosin-stained slides detected amastigotes in an additional 17 samples. Meanwhile, 31/114 samples (27.2%) were positive for Leishmania spp. kinetoplast deoxyribonucleic acid (kDNA) by PCR analysis. Of these, 17 (54.8%) yielded amplification of the mini-exon PCR target, thereby allowing for PCR-RFLP-based identification. Six of the samples were identified as L. (V.) braziliensis, while the remaining 11 were identified as L. (V.) guyanensis. The results of this study demonstrate the feasibility of applying molecular techniques for the diagnosis of human parasites within paraffin-embedded tissues. Moreover, our findings confirm that L. (V.) guyanensisis a relevant causative agent of mucosal leishmaniasis in the Brazilian Amazon.

Environmental contamination by Toxocara spp. Eggs in a rural settlement in Brazil Contaminação ambiental por ovos de Toxocara spp. em assentamento rural no Brasil

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Vamilton Alvares Santarém

2008-10-01

Full Text Available In order to study the environmental contamination by Toxocara spp. eggs in a rural community from the Pontal do Paranapanema region, São Paulo State, Brazil, soil samples from 31 out of 121 plots were collected in eight different places on each house. The samples were submitted to flotation technique in sodium nitrate (d = 1.20g/cm³. Eggs of Toxocara spp. were recovered in nine (29.03% out of the 31 plots. At least one dog was registered in 27 of the 31 plots examined (87.1% and at least one cat in 17 (54.84%. The number of pets per plot ranged from one to six (mean of 2.3 for dogs and one to 14 (mean of 1.29 for cats. In 16 plots (51.61%, the presence of both dogs and cats was observed. There was no relation between the presence of pets in the plots and soil contamination (p > 0.05. However, the environmental contamination by Toxocara spp. eggs associated to the poor conditions of the inhabitants may be an important risk factor for the human population to ocular or visceral larva migrans.Com o objetivo de avaliar a contaminação ambiental por ovos de Toxocara spp. em assentamento rural da região do Pontal do Paranapanema, oeste do estado de São Paulo, Brasil, amostras de solo de oito diferentes pontos ao redor da casa de 31 dos 121 lotes do assentamento foram coletados. A recuperação de ovos foi realizada pela técnica de centrífugo-flutuação em solução de nitrato de sódio (d = 1,20g/cm³. Ovos de Toxocara spp. foram recuperados em nove (29,03% dos 31 lotes. Em 27 das 31 casas amostradas (87,1%, havia pelo menos um cão e em 17 (54,84% pelo menos um gato. O número de cães por lote variou de um a seis (media de 2,3. No caso dos gatos, o número variou de um a 14 (média de 1,29. Em 16 dos 31 lotes (51,61%, havia a presença de pelo menos um cão ou gato. Não houve relação entre a presença desses animais e a contaminação do solo (p > 0,05. Entretanto, a contaminação do solo por ovos de Toxocara spp. e as precárias condi

Molecular and serological detection of tick-borne pathogens in dogs from an area endemic for Leishmania infantumin Mato Grosso do Sul, Brazil

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Keyla Carstens Marques de Sousa

Full Text Available Tick-borne pathogens affect a wide range of vertebrate hosts. To identify tick-borne pathogens among dogs from Campo Grande, MS, Brazil testing seropositive for Leishmania infantum (syn. L. chagasi, a serological and molecular study was conducted to detectEhrlichia canis, Anaplasma platys and Babesia vogeli in 60 serum and spleen samples. A confirmatory diagnosis ofL. infantum based on serological and molecular assays was also performed, as was sequence alignment and phylogenetic analysis to assess the identity of the parasite species infecting these animals. IgG antibodies toEhrlichia spp., B. vogeli and L. infantum were found, respectively, in 39 (65%, 49 (81.6% and 60 (100% of the sampled dogs. Twenty-seven (45%, fifty-four (90%, fifty-three (88.3%, two (3.3% and one (1.6% dog were positive, respectively, forE. canis, Leishmania spp., Leishmania donovani complex, Babesia sp. and Anaplasma sp. in PCR assays. After sequencing, the amplicons showed 99% of identity with E. canis, B. vogeli, A. platys andLeishmania chagasi isolates. The findings of this study indicate that L. infantum-seropositive dogs from Campo Grande are exposed to multiple tick-borne pathogens, which should therefore be included in the differential diagnosis of dogs with clinical suspicion of leishmaniasis.

LeishCyc: a biochemical pathways database for Leishmania major

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Doyle Maria A

2009-06-01

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

Mastite bovina causada por Staphylococcus spp. resistentes à meticilina: revisão de literatura

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José Givanildo Silva

Full Text Available RESUMO: Staphylococcus spp. são os micro-organismos mais relacionados a casos de mastite bovina. Algumas cepas destes micro-organismos têm apresentado fatores de virulência como genes de resistência a antimicrobianos com destaque para a resistência à meticilina que é um problema de saúde pública. Esta revisão de literatura tem o objetivo de compilar dados sobre a mastite bovina causada por Staphylococcus spp. resistente à meticilina (MRS. Apesar desse antimicrobiano não ser comumente utilizado no tratamento das mastites, a frequência de casos de infecção da glândula mamária causada por MRS tem variado entre 1,34 a 47,6%. Acredita-se que o contato dos humanos com animais positivos para MRS e vice-versa favoreça a transmissão deste patógeno entre as espécies, contribuindo para a variação nas taxas de infecção. A detecção de MRS pode ser realizada por meio de provas fenotípicas, moleculares ou sorológicas e as medidas de controle devem contemplar a identificação dos casos, segregação dos animais, estudo epidemiológico da fonte de infecção do rebanho, além da constante limpeza e higienização do ambiente de confinamento, equipamentos e utensílios de ordenha. Casos de mastite ocasionados por esse patógeno assumem relevância para a saúde pública, pois a ingestão de leite e/ou derivados contaminados podem desencadear a transferência de MRS para seres humanos. Com isso, é necessário um alerta constante quanto à vigilância epidemiológica em fazendas leiteiras.

Hepatozoon canis and Leishmania spp. coinfection in dogs diagnosed with visceral leishmaniasis

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Fernanda Nazaré Morgado

Full Text Available Abstract This study describes the occurrence of dogs naturally co-infected with Hepatozoon canis and two Leishmania species: L. infantum or L. braziliensis. Four dogs serologically diagnosed with Visceral Leishmaniasis were euthanized. Liver and spleen samples were collected for histopathological analysis and DNA isolation. H. canis meronts were observed in tissues from all four dogs. H. canis infection was confirmed by PCR followed by sequencing of a fragment of 18S rRNA gene. Leishmania detection and typing was confirmed by ITS1' PCR-RFLP and parasite burden was calculated using ssrRNA quantitative qPCR. A DPP - Dual Path platform test was performed. One out (Dog #2 of four animals was asymptomatic. Dogs #1 and #4 were infected by L. infantum and were DPP test positive. Dogs #2 and #3 were infected by L. braziliensis and were DPP test negative. Furthermore, visceral dissemination was observed in Dogs #2 and #3, since L. braziliensis was detected in liver and spleen samples. The visceral dissemination of L. braziliensis associated with systemic signs suggested that this co-infection could influence the parasite burden and disease progression.

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

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Patrícia Flávia Quaresma

2012-06-01

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

The Gut Microbiome of the Vector Lutzomyia longipalpis Is Essential for Survival of Leishmania infantum.

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Kelly, Patrick H; Bahr, Sarah M; Serafim, Tiago D; Ajami, Nadim J; Petrosino, Joseph F; Meneses, Claudio; Kirby, John R; Valenzuela, Jesus G; Kamhawi, Shaden; Wilson, Mary E

2017-01-17

The vector-borne disease leishmaniasis, caused by Leishmania species protozoa, is transmitted to humans by phlebotomine sand flies. Development of Leishmania to infective metacyclic promastigotes in the insect gut, a process termed metacyclogenesis, is an essential prerequisite for transmission. Based on the hypothesis that vector gut microbiota influence the development of virulent parasites, we sequenced midgut microbiomes in the sand fly Lutzomyia longipalpis with or without Leishmania infantum infection. Sucrose-fed sand flies contained a highly diverse, stable midgut microbiome. Blood feeding caused a decrease in microbial richness that eventually recovered. However, bacterial richness progressively decreased in L. infantum-infected sand flies. Acetobacteraceae spp. became dominant and numbers of Pseudomonadaceae spp. diminished coordinately as the parasite underwent metacyclogenesis and parasite numbers increased. Importantly, antibiotic-mediated perturbation of the midgut microbiome rendered sand flies unable to support parasite growth and metacyclogenesis. Together, these data suggest that the sand fly midgut microbiome is a critical factor for Leishmania growth and differentiation to its infective state prior to disease transmission. Leishmania infantum, a parasitic protozoan causing fatal visceral leishmaniasis, is transmitted to humans through the bite of the sand fly Lutzomyia longipalpis Development of the parasite to its virulent metacyclic state occurs in the sand fly gut. In this study, the microbiota within the Lu. longipalpis midgut was delineated by 16S ribosomal DNA (rDNA) sequencing, revealing a highly diverse community composition that lost diversity as parasites developed to their metacyclic state and increased in abundance in infected flies. Perturbing sand fly gut microbiota with an antibiotic cocktail, which alone had no effect on either the parasite or the fly, arrested both the development of virulent parasites and parasite expansion

PCR-RFLP y RAPD para la tipificación de Leishmania neotropical

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Ana Margarita Montalvo

2008-12-01

Full Text Available Introducción. El análisis de la longitud de los fragmentos de restricción del producto amplificado y el estudio del ADN polimórfico amplificado al azar han demostrado ser herramientas útiles para la tipificación de Leishmania. Objetivos. Estudiar la utilidad de las técnicas moleculares para la identificación y tipificación de cepas de referencia de Leishmania spp. del Nuevo Mundo y valorar su aplicabilidad a muestras clínicas. Materiales y métodos. Se aplicó PCR para amplificar el gen que codifica la cisteíno-proteinasa B, y el análisis de la longitud de los fragmentos de restricción del producto amplificado utilizando ácido desoxirribonucleico de 16 cepas de referencia de Latinoamérica y de muestras clínicas de pacientes colombianos con leishmaniasis, y la técnica del ácido desoxirribonucleico polimórfico amplificado al azar utilizando ocho cepas de referencia. Se establecieron los patrones de bandas en cada caso. Resultados. Se obtuvo producto de amplificación en la PCR para Leishmania braziliensis, L. peruviana, L. panamensis y L. guyanensis. Para el resto, no fue posible amplificar el gen con los cebadores utilizados. La restricción mostró un patrón de bandas común para L. peruviana, L. guyanensis y L. panamensis, mientras L. braziliensis, presentaba un perfil individual único. El análisis de restricción del producto amplificado generó un patrón de bandas similar en los cinco pacientes estudiados, que se correspondía con el patrón generado por L. peruviana, L. guyanensis o L. panamensis. Mediante la amplificación al azar se obtuvieron patrones de bandas reproducibles con todas las cepas estudiadas, que posibilitaron la diferenciación. Se discuten las ventajas y limitaciones de ambos procederes. Conclusiones. El combinar ambas metodologías resultaría útil para identificar especies de importancia médica, tomando en cuenta sus ventajas y desventajas.

Leishmania (Viannia) braziliensis infection in wild small mammals in ecotourism area of Brazil.

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Tonelli, Gabriel Barbosa; Tanure, Aline; Rego, Felipe Dutra; Carvalho, Gustavo Mayr de Lima; Stumpp, Rodolfo; Ássimos, Gabriela Ribeiro; Campos, Aldenise Martins; Lima, Ana Cristina Viana Mariano da Rocha; Gontijo, Célia Maria Ferreira; Paz, Gustavo Fontes; Andrade Filho, José Dilermando

2017-01-01

Leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (Diptera: Psychodidae). Despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. The Reserva Particular do Patrimônio Natural Santuário do Caraça (RPPNSC) is one of the largest ecotourism attractions in the State of Minas Gerais, Brazil, and comprises an area of environmental preservation with 11,233 hectares presenting a transitional vegetation between Cerrado and Atlantic Forest. The present study describes the abundance of small mammals in RPPNSC, the isolation and identification of Leishmania in five wild animals. Small mammals were bimonthly trapped along 6 trails within the RPPNSC with 10 Tomahawk traps each. Two trails were located in peridomiciliary areas near tourist lodging facilities, and four trails were located at sites visited by tourists in forest areas. The most prevalent species were Akodon cursor, Cerradomys subflavus and Oligoryzomys nigripes. Six isolates of Leishmania were obtained from these animals and identified as Leishmania braziliensis through HSP70-PCR RFLP method. Leishmania spp. DNA was detected by kDNA-PCR method and isolated by biphasic culture. Studies point to some of the captured species as potential wild reservoirs of Leishmania, suggesting they may be involved in the transmission cycle in these wild environments.

Increased transmission potential of Leishmania major/Leishmania infantum hybrids

OpenAIRE

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

2007-01-01

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

Novel selective inhibitor of Leishmania (Leishmania) amazonensis arginase.

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

2015-11-01

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

Distribution and identification of sand flies naturally infected with Leishmania from the Southeastern Peruvian Amazon.

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Victor Zorrilla

2017-11-01

Full Text Available Cutaneous leishmaniasis (CL is an important health problem in the New World affecting civilian and military populations that are frequently exposed in endemic settings. The Peruvian region of Madre de Dios located near the border with Brazil is one of the most endemic CL regions in South America with more than 4,451 reported cases between 2010 and 2015 according to the Peruvian epidemiology directorate. However, little is known regarding the diversity and distribution of sand fly vectors in this region. In this study, we aimed to characterize the sand fly fauna in this endemic setting and identify sand fly species naturally infected with Leishmania possibly involved in pathogen transmission.Sand fly collections were carried out during 2014 and 2015 in the communities of Flor de Acre, Villa Primavera, Mavila and Arca Pacahuara using CDC light traps and Shannon traps. Collected specimens were identified and non-blood-fed females were selected for Leishmania infection screening using kinetoplastid DNA-PCR (kDNA-PCR and nested Real time PCR for species identification.A total of 10,897 phlebotomines belonging to the genus Lutzomyia (58 species and Brumptomyia (2 species were collected. Our study confirmed the widespread distribution and abundance of Lutzomyia (Trichophoromyia spp. (24%, Lu. whitmani (19.4% and Lu. yucumensis (15.8% in the region. Analysis of Shannon diversity index indicates variability in sand fly composition across sites with Villa Primavera presenting the highest sand fly diversity and abundance. Leishmania screening by kDNA-PCR resulted in 45 positive pools collected from Flor de Acre (34 pools, Mavila (10 pools and Arca Pacahuara (1 pool and included 14 species: Lu. yucumensis, Lu. aragoi, Lu. sallesi, Lu. sherlocki, Lu. shawi, Lu. walkeri, Lu nevesi, Lu. migonei, Lu. davisi, Lu. carrerai, Lu. hirsuta, Lu. (Trichophoromyia spp., Lu. llanosmartinsi and Lu. whitmani. Lutzomyia sherlocki, Lu. walkeri and Lu. llanosmartinsi had the

Distribution and identification of sand flies naturally infected with Leishmania from the Southeastern Peruvian Amazon.

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Zorrilla, Victor; De Los Santos, Maxy B; Espada, Liz; Santos, Rocío Del Pilar; Fernandez, Roberto; Urquia, Albino; Stoops, Craig A; Ballard, Sarah-Blythe; Lescano, Andres G; Vásquez, Gissella M; Valdivia, Hugo O

2017-11-01

Cutaneous leishmaniasis (CL) is an important health problem in the New World affecting civilian and military populations that are frequently exposed in endemic settings. The Peruvian region of Madre de Dios located near the border with Brazil is one of the most endemic CL regions in South America with more than 4,451 reported cases between 2010 and 2015 according to the Peruvian epidemiology directorate. However, little is known regarding the diversity and distribution of sand fly vectors in this region. In this study, we aimed to characterize the sand fly fauna in this endemic setting and identify sand fly species naturally infected with Leishmania possibly involved in pathogen transmission. Sand fly collections were carried out during 2014 and 2015 in the communities of Flor de Acre, Villa Primavera, Mavila and Arca Pacahuara using CDC light traps and Shannon traps. Collected specimens were identified and non-blood-fed females were selected for Leishmania infection screening using kinetoplastid DNA-PCR (kDNA-PCR) and nested Real time PCR for species identification. A total of 10,897 phlebotomines belonging to the genus Lutzomyia (58 species) and Brumptomyia (2 species) were collected. Our study confirmed the widespread distribution and abundance of Lutzomyia (Trichophoromyia) spp. (24%), Lu. whitmani (19.4%) and Lu. yucumensis (15.8%) in the region. Analysis of Shannon diversity index indicates variability in sand fly composition across sites with Villa Primavera presenting the highest sand fly diversity and abundance. Leishmania screening by kDNA-PCR resulted in 45 positive pools collected from Flor de Acre (34 pools), Mavila (10 pools) and Arca Pacahuara (1 pool) and included 14 species: Lu. yucumensis, Lu. aragoi, Lu. sallesi, Lu. sherlocki, Lu. shawi, Lu. walkeri, Lu nevesi, Lu. migonei, Lu. davisi, Lu. carrerai, Lu. hirsuta, Lu. (Trichophoromyia) spp., Lu. llanosmartinsi and Lu. whitmani. Lutzomyia sherlocki, Lu. walkeri and Lu. llanosmartinsi had the

Distribution and identification of sand flies naturally infected with Leishmania from the Southeastern Peruvian Amazon

Science.gov (United States)

Zorrilla, Victor; De Los Santos, Maxy B.; Espada, Liz; Santos, Rocío del Pilar; Fernandez, Roberto; Urquia, Albino; Stoops, Craig A.; Ballard, Sarah-Blythe; Lescano, Andres G.; Vásquez, Gissella M.; Valdivia, Hugo O.

2017-01-01

Background Cutaneous leishmaniasis (CL) is an important health problem in the New World affecting civilian and military populations that are frequently exposed in endemic settings. The Peruvian region of Madre de Dios located near the border with Brazil is one of the most endemic CL regions in South America with more than 4,451 reported cases between 2010 and 2015 according to the Peruvian epidemiology directorate. However, little is known regarding the diversity and distribution of sand fly vectors in this region. In this study, we aimed to characterize the sand fly fauna in this endemic setting and identify sand fly species naturally infected with Leishmania possibly involved in pathogen transmission. Methods Sand fly collections were carried out during 2014 and 2015 in the communities of Flor de Acre, Villa Primavera, Mavila and Arca Pacahuara using CDC light traps and Shannon traps. Collected specimens were identified and non-blood-fed females were selected for Leishmania infection screening using kinetoplastid DNA-PCR (kDNA-PCR) and nested Real time PCR for species identification. Results A total of 10,897 phlebotomines belonging to the genus Lutzomyia (58 species) and Brumptomyia (2 species) were collected. Our study confirmed the widespread distribution and abundance of Lutzomyia (Trichophoromyia) spp. (24%), Lu. whitmani (19.4%) and Lu. yucumensis (15.8%) in the region. Analysis of Shannon diversity index indicates variability in sand fly composition across sites with Villa Primavera presenting the highest sand fly diversity and abundance. Leishmania screening by kDNA-PCR resulted in 45 positive pools collected from Flor de Acre (34 pools), Mavila (10 pools) and Arca Pacahuara (1 pool) and included 14 species: Lu. yucumensis, Lu. aragoi, Lu. sallesi, Lu. sherlocki, Lu. shawi, Lu. walkeri, Lu nevesi, Lu. migonei, Lu. davisi, Lu. carrerai, Lu. hirsuta, Lu. (Trichophoromyia) spp., Lu. llanosmartinsi and Lu. whitmani. Lutzomyia sherlocki, Lu. walkeri and Lu

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

Energy Technology Data Exchange (ETDEWEB)

Bonetti, Franco Claudio

2006-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Bonetti, Franco Claudio

2006-07-01

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

Changes to cholesterol trafficking in macrophages by Leishmania parasites infection.

Science.gov (United States)

Semini, Geo; Paape, Daniel; Paterou, Athina; Schroeder, Juliane; Barrios-Llerena, Martin; Aebischer, Toni

2017-08-01

Leishmania spp. are protozoan parasites that are transmitted by sandfly vectors during blood sucking to vertebrate hosts and cause a spectrum of diseases called leishmaniases. It has been demonstrated that host cholesterol plays an important role during Leishmania infection. Nevertheless, little is known about the intracellular distribution of this lipid early after internalization of the parasite. Here, pulse-chase experiments with radiolabeled cholesteryl esterified to fatty acids bound to low-density lipoproteins indicated that retention of this source of cholesterol is increased in parasite-containing subcellular fractions, while uptake is unaffected. This is correlated with a reduction or absence of detectable NPC1 (Niemann-Pick disease, type C1), a protein responsible for cholesterol efflux from endocytic compartments, in the Leishmania mexicana habitat and infected cells. Filipin staining revealed a halo around parasites within parasitophorous vacuoles (PV) likely representing free cholesterol accumulation. Labeling of host cell membranous cholesterol by fluorescent cholesterol species before infection revealed that this pool is also trafficked to the PV but becomes incorporated into the parasites' membranes and seems not to contribute to the halo detected by filipin. This cholesterol sequestration happened early after infection and was functionally significant as it correlated with the upregulation of mRNA-encoding proteins required for cholesterol biosynthesis. Thus, sequestration of cholesterol by Leishmania amastigotes early after infection provides a basis to understand perturbation of cholesterol-dependent processes in macrophages that were shown previously by others to be necessary for their proper function in innate and adaptive immune responses. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?

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Felipe da Silva Krawczak

2015-02-01

Full Text Available INTRODUCTION: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites. METHODS: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT and by anti-Leishmania immunoglobulin G (IgG antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP (Bio Manguinhos(r/FIOCRUZ/MS and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios. RESULTS : Of 96 serum samples submitted to serological assays, 4 (4.2% were positive for Leishmania as determined by ELISA; 12 (12.5%, by IFAT; 14 (14.6% by rK39 RDT; and 20 (20.8%, by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9% and 30/96 (31.2% samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05. CONCLUSIONS: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil; we also found that the serological tests that were used did not cross-react.

Ecology, feeding and natural infection by Leishmania spp. of phlebotomine sand flies in an area of high incidence of American tegumentary leishmaniasis in the municipality of Rio Branco, Acre, Brazil.

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de Ávila, Márcia Moreira; Brilhante, Andreia Fernandes; de Souza, Cristian Ferreira; Bevilacqua, Paula Dias; Galati, Eunice Aparecida Bianchi; Brazil, Reginaldo Peçanha

2018-01-26

Phlebotomine sand flies (Diptera: Psychodidae) are insects of medical importance due to their involvement in the zoonotic transmission of Leishmania spp. to vertebrates. The aim of this work was to study the ecology of the sand fly fauna of two types of environments, a rural environment (the Transacreana Road) and an urban park (Horto Florestal Park), both located in the municipality of Rio Branco in the state of Acre, Brazil. Additionally, this study intended to investigate Leishmania infection and blood meal sources of these sand flies using molecular techniques. The sand fly fauna was studied in different environments (i.e. forest and peridomestic environments in a rural area, and an urban forest) using Shannon traps and HP light traps to collect sand fly specimens over 13 consecutive months (December 2014 to January 2016). For investigating natural infection by Leishmania and the source of sand fly blood meals, DNA samples were extracted from female sand flies and subjected to polymerase chain reaction targeting ITS1 and cytb genes. DNA sequencing was subsequently used to identify species of Leishmania and the source of blood meals. A total of 2515 individual sand flies of 43 species were collected and identified, Trichophoromyia auraensis (839; 33.35%), Trichophoromyia spp. (537; 21.35%) and Evandromyia saulensis (187; 7.43%) were more abundant in the rural area (S = 41 species) than in the urban forest. No significant differences were found in species richness between forest and peridomestic environments in the rural area (H = 0.04; P > 0.05), but a larger number of species was found in the forest. Leishmania DNA was sequenced in 13 samples, confirming the presence of L. (V.) braziliensis in Th. auraensis (n = 1), Ev. saulensis (n = 2), Ev. walkeri (n = 1), Ps. llanosmartinsi (n = 1), Pi. nevesi (n = 2), Ps. davisi (n = 1), Ps. ayrozai (n = 1), Pa. aragaoi (n = 1), Ny. antunesi (n = 1) and Ev. infraspinosa (n�

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

International Nuclear Information System (INIS)

Bonetti, Franco Claudio

2006-01-01

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

Amplified DNAs in laboratory stocks of Leishmania tarentolae: extrachromosomal circles structurally and functionally similar to the inverted-H-region amplification of methotrexate-resistant Leishmania major

International Nuclear Information System (INIS)

Petrillo-Peixoto, M.L.; Beverley, S.M.

1988-01-01

We describe the structure of amplified DNA that was discovered in two laboratory stocks of the protozoan parasite Leishmania tarentolae. Restriction mapping and molecular cloning revealed that a region of 42 kilobases was amplified 8- to 30-fold in these lines. Southern blot analyses of digested DNAs or chromosomes separated by pulsed-field electrophoresis showed that the amplified DNA corresponded to the H region, a locus defined originally by its amplification in methotrexate-resistant Leishmania major. Similarities between the amplified DNA of the two species included (i) extensive cross-hybridization; (ii) approximate conservation of sequence order; (iii) extrachromosomal localization; (iv) an overall inverted, head-to-head configuration as a circular 140-kilobase tetrameric molecule; (v) two regions of DNA sequence rearrangement, each of which was closely associated with the two centers of the inverted repeats; (vi) association with methotrexate resistance; and (vii) phenotypically conservative amplification, in which the wild-type chromosomal arrangement was retained without apparent modification. Our data showed that amplified DNA mediating drug resistance arose in unselected L. tarentolae, although the pressures leading to apparently spontaneous amplification and maintenance of the H region are not known. The simple structure and limited extent of DNA amplified in these and other Leishmania lines suggests that the study of gene amplification in Leishmania spp. offers an attractive model system for the study of amplification in cultured mammalian cells and tumors. We also introduced a method for measuring the size of large circular DNAs, using gamma-irradiation to introduce limited double-strand breaks followed by sizing of the linear DNAs by pulsed-field electrophoresis

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

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F.L.C. Brito

2007-02-01

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

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

Science.gov (United States)

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

2017-03-29

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

Aspectos epidemiológicos de pacientes com lesões ungueais e cutâneas causadas por Scytalidium spp Epidemiological aspects of patients with ungual and cutaneous lesions caused by Scytalidium spp

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Ana Paula Martins Xavier

2010-12-01

Full Text Available FUNDAMENTO: As dermatomicoses causadas por fungos filamentosos não dermatófitos são infecções raras, exceto as onicomicoses, cuja prevalência vem crescendo nos últimos anos. Dentre esses agentes etiológicos destacam-se o Scytalidium dimidiatum e o S. hyalinum, fungos emergentes responsáveis por micoses em unhas e pele. OBJETIVO: Investigar as características epidemiológicas das onicomicoses e micoses de outras localizações causadas pelos fungos do gênero Scytalidium, utilizando-se como parâmetros sexo, idade e localizações das lesões. MÉTODOS: Avaliaram-se 81 amostras com cultura positiva para o gênero em estudo, oriundas de 74 pacientes encaminhados ao Laboratório de Investigação em Dermatologia (ID situado na cidade do Rio de Janeiro (RJ, no período de 1997 a 2006. As amostras foram submetidas a confirmação diagnóstica por exame direto e cultura. RESULTADOS: A prevalência de onicomicoses por Scytalidium spp. foi de 0,87%, entre as idades de 41 e 60 anos (48,64%. Em relação à localização das lesões, os pés foram mais acometidos (91,36%, com predomínio do hálux esquerdo. No exame direto, as estruturas mais encontradas foram hifas hialinas; na cultura, a espécie S. dimidiatum foi a mais frequente. CONCLUSÃO: As onicomicoses por Scytalidium spp. são raras e o S. dimidiatum foi a espécie mais isolada neste laboratório no período em estudo.BACKGROUND: Dermatomycoses caused by non-dermatophyte filamentous fungi are rare infections, except for onychomycosis, whose prevalence has increased over the past few years. Among these etiologic agents, we highlight Scytalidium dimidiatum and S. hyalinum, emergent fungi that cause mycoses that affect the nails and skin. OBJECTIVE: To investigate the characteristics of onychomycosis and other mycoses caused by the fungi Scytalidium spp, using sex, age and site of infection as parameters. METHODS: Eighty-one samples were evaluated showing positive culture for Scytalidium

Arginase activity in pathogenic and non-pathogenic species of Leishmania parasites.

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Badirzadeh, Alireza; Taheri, Tahereh; Taslimi, Yasaman; Abdossamadi, Zahra; Heidari-Kharaji, Maryam; Gholami, Elham; Sedaghat, Baharehsadat; Niyyati, Maryam; Rafati, Sima

2017-07-01

Proliferation of Leishmania (L.) parasites depends on polyamine availability, which can be generated by the L-arginine catabolism and the enzymatic activity of arginase (ARG) of the parasites and of the mammalian hosts. In the present study, we characterized and compared the arginase (arg) genes from pathogenic L. major and L. tropica and from non-pathogenic L. tarentolae. We quantified the level of the ARG activity in promastigotes and macrophages infected with pathogenic L. major and L. tropica and non-pathogenic L. tarentolae amastigotes. The ARG's amino acid sequences of the pathogenic and non-pathogenic Leishmania demonstrated virtually 98.6% and 88% identities with the reference L. major Friedlin ARG. Higher ARG activity was observed in all pathogenic promastigotes as compared to non-pathogenic L. tarentolae. In vitro infection of human macrophage cell line (THP1) with pathogenic and non-pathogenic Leishmania spp. resulted in increased ARG activities in the infected macrophages. The ARG activities present in vivo were assessed in susceptible BALB/c and resistant C57BL/6 mice infected with L. major, L. tropica and L. tarentolae. We demonstrated that during the development of the infection, ARG is induced in both strains of mice infected with pathogenic Leishmania. However, in L. major infected BALB/c mice, the induction of ARG and parasite load increased simultaneously according to the time course of infection, whereas in C57BL/6 mice, the enzyme is upregulated solely during the period of footpad swelling. In L. tropica infected mice, the footpads' swellings were slow to develop and demonstrated minimal cutaneous pathology and ARG activity. In contrast, ARG activity was undetectable in mice inoculated with the non-pathogenic L. tarentolae. Our data suggest that infection by Leishmania parasites can increase ARG activity of the host and provides essential polyamines for parasite salvage and its replication. Moreover, the ARG of Leishmania is vital for parasite

A preliminary parasitological survey of hepatozoon spp. Infection in dogs in mashhad, iran.

Science.gov (United States)

Amoli, Aa Rahmani; Khoshnegah, J; Razmi, Ghr

2012-01-01

We attempted to determine the prevalence of Hepatozoon spp. infection in Mashhad, northeast of Iran, via blood smear parasitology. The prevalence was investigated by examination of blood smear parasitology, using blood samples collected from 254 dogs (51 strays and 203 privately owned-dogs). Two stray dogs (2/51; 3.92%) and two privately-owned dogs (2/203; 0.98%) were infected with Hepatozoon spp. Therefore, as per blood smear parasitology, the prevalence of Hepatozoon spp. infection was 1.57% (4/254). Sixteen out of 254 dogs (6.29%) were infested with ticks; all of which were Rhipicephalus sanguineus. One of the dogs infected with Hepatozoon spp. exhibited ticks at the time of examination. Concurrent infection with Ehrlichia canis and Leishmania infantum was not detected in the four Hepatozoon spp. infected dogs. This is the first epidemiological study on the prevalence of Hepatozoon spp. infection in dogs in Iran.

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

Science.gov (United States)

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

2015-12-01

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

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

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

2016-12-01

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

In-silico Leishmania Target Selectivity of Antiparasitic Terpenoids

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Ifedayo Victor Ogungbe

2013-07-01

Full Text Available Neglected Tropical Diseases (NTDs, like leishmaniasis, are major causes of mortality in resource-limited countries. The mortality associated with these diseases is largely due to fragile healthcare systems, lack of access to medicines, and resistance by the parasites to the few available drugs. Many antiparasitic plant-derived isoprenoids have been reported, and many of them have good in vitro activity against various forms of Leishmania spp. In this work, potential Leishmania biochemical targets of antiparasitic isoprenoids were studied in silico. Antiparasitic monoterpenoids selectively docked to L. infantum nicotinamidase, L. major uridine diphosphate-glucose pyrophosphorylase and methionyl t-RNA synthetase. The two protein targets selectively targeted by germacranolide sesquiterpenoids were L. major methionyl t-RNA synthetase and dihydroorotate dehydrogenase. Diterpenoids generally favored docking to L. mexicana glycerol-3-phosphate dehydrogenase. Limonoids also showed some selectivity for L. mexicana glycerol-3-phosphate dehydrogenase and L. major dihydroorotate dehydrogenase while withanolides docked more selectively with L. major uridine diphosphate-glucose pyrophosphorylase. The selectivity of the different classes of antiparasitic compounds for the protein targets considered in this work can be explored in fragment- and/or structure-based drug design towards the development of leads for new antileishmanial drugs.

Purificación de dos proteínas de Leishmania Viannia panamensis y su utilización en el diagnóstico de casos de leishmaniosis cutánea de larga evolución y difícil diagnóstico parasitológico

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Sonia Agudelo

2001-04-01

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La respuesta inmune humoral inducida por Leishmania spp, se inicia desde la etapa temprana de la infección y se mantiene hasta cuando la mayoría de los parásitos son eliminados. Los isotipos, subclases y niveles de anticuerpos que evalúan esta respuesta dependen en gran medida de la forma clínica y el estado de evolución de la enfermedad. En casos de lesiones mucosas o cutáneas de larga evolución donde la posibilidad de encontrar parásitos es baja, toma gran importancia evaluar esta respuesta humoral. Sin embargo, las técnicas serológicas existentes para detectar anticuerpos antileishmania presentan baja sensibilidad y alta reacción cruzada con parásitos de Trypanosoma cruzi, surgiendo, como una alternativa para mejorar estas pruebas, el uso de antígenos proteicos purificados (1,2. Teniendo como base los resultados obtenidos por Agudelo y col (3, quienes demostraron que las fracciones proteicas de 36 y 50 kDa de Leishmania Viannia panamensis son altamente sensibles y
100% específicas de Leishmania, nos proponemos purificar estas proteínas a fin de utilizarlas para mejorar la sensibilidad y especificidad de pruebas serológicas que sean económicas y de ejecución práctica en zonas endémicas de leishmaniosis.

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

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Bordbar, Ali; Parvizi, Parviz

2014-03-01

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

A Preliminary Parasitological Survey of Hepatozoon Spp. Infection in Dogs in Mashhad, Iran

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J Khoshnegah

2012-12-01

Full Text Available Background: We attempted to determine the prevalence of Hepatozoon spp. infection in Mashhad, northeast of Iran, via blood smear parasitology.Methods: The prevalence was investigated by examination of blood smear parasitology, using blood samples collected from 254 dogs (51 strays and 203 privately owned-dogs.Results: Two stray dogs (2/51; 3.92% and two privately-owned dogs (2/203; 0.98% were infected with Hepatozoon spp. Therefore, as per blood smear parasitology, the prevalence of Hepatozoon spp. infection was 1.57% (4/254. Sixteen out of 254 dogs (6.29% were infested with ticks; all of which were Rhipicephalus sanguineus. One of the dogs infected with Hepatozoon spp. exhibited ticks at the time of examination. Concurrent infection with Ehrlichia canis and Leishmania infantum was not detected in the four Hepatozoon spp. infected dogs.Conclusion: This is the first epidemiological study on the prevalence of Hepatozoon spp. infection in dogs in Iran.

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

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Albino Verçosa de Magalhães

1986-10-01

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

Promoção do crescimento do feijoeiro e controle da antracnose por Trichoderma spp

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Erica Aparecida de Souza Pedro

2012-11-01

Full Text Available O objetivo deste trabalho foi avaliar a capacidade de Trichoderma spp. em promover o crescimento de plantas de feijão e reduzir a severidade da antracnose do feijoeiro (Colletotrichum lindemuthianum, bem como identificar os isolados mais eficientes. Sessenta isolados de Trichoderma spp. foram avaliados quanto à capacidade de promoção do crescimento nas plantas. Os sete isolados que mais se destacaram foram adicionados ao substrato de cultivo e avaliados quanto à redução na severidade da antracnose em plantas de feijão tratadas com conídios de C. lindemuthianum. Os mais eficientes no controle da doença foram identificados por sequenciamento de DNA. O isolado IB 28/07 foi avaliado nas concentrações 0,5, 1, 1,5 e 2% (peso:volume, que reduziram a severidade da doença em 41,51, 55,15, 81,82 e 96,06%, respectivamente. Os isolados mais eficientes de Trichoderma spp. podem proporcionar aumentos superiores a 30% na produção de matéria seca da parte aérea das plantas e reduzir a severidade da doença entre 63 e 98%. Esses isolados foram identificados como pertencentes às espécies Trichoderma harzianum, T. strigosum e T. theobromicola.

Leishmania spp. Epidemiology of Canine Leishmaniasis in the Yucatan Peninsula

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A. López-Céspedes

2012-01-01

Full Text Available Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico. A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula.

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López-Céspedes, A; Longoni, S S; Sauri-Arceo, C H; Sánchez-Moreno, M; Rodríguez-Vivas, R I; Escobedo-Ortegón, F J; Barrera-Pérez, M A; Bolio-González, M E; Marín, C

2012-01-01

Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

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

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Danielle El Atra Coelho

2017-03-01

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

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

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Lívia O Santos

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

Leishmania species identification using FTA card sampling directly from patients' cutaneous lesions in the state of Lara, Venezuela.

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Kato, Hirotomo; Watanabe, Junko; Mendoza Nieto, Iraida; Korenaga, Masataka; Hashiguchi, Yoshihisa

2011-10-01

A molecular epidemiological study was performed using FTA card materials directly sampled from lesions of patients with cutaneous leishmaniasis (CL) in the state of Lara, Venezuela, where causative agents have been identified as Leishmania (Viannia) braziliensis and L. (Leishmania) venezuelensis in previous studies. Of the 17 patients diagnosed with CL, Leishmania spp. were successfully identified in 16 patients based on analysis of the cytochrome b gene and rRNA internal transcribed spacer sequences. Consistent with previous findings, seven of the patients were infected with L. (V.) braziliensis. However, parasites from the other nine patients were genetically identified as L. (L.) mexicana, which differed from results of previous enzymatic and antigenic analyses. These results strongly suggest that L. (L.) venezuelensis is a variant of L. (L.) mexicana and that the classification of L. (L.) venezuelensis should be reconsidered. Copyright © 2011 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Human cutaneous leishmaniasis caused by Leishmania (Viannia braziliensis in Santiago del Estero, Argentina: identification of parasites by monoclonal antibodies and isoenzymes Leishmaniose cutânea humana causada por Leishmania (Viannia braziliensis na Província de Santiago del Estero, Argentina: identificação dos parasitas por anticorpos monoclonais e isoenzimas

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C.A. Cuba Cuba

1996-12-01

pacientes humanos com lesões cutâneas de leishmaniose na Província de Santiago del Estero, no Norte da Argentina. Os procedimentos de diagnóstico foram: biópsias de lesões para utilização em esfregaços e inoculação em hamster; aspiração (com agulha de úlceras, para cultura "in vitro". As técnicas imunodiagnósticas empregadas foram a IFAT-IgG e o teste intradérmico de Montenegro. Oito cepas de parasitas foram isoladas, sendo estas obtidas de pacientes com lesões ativas. Todas as cepas foram inicialmente caracterizadas biologicamente por seu comportamento na infecção experimental do hamster, mensuração dos amastigotas e promastigotas e crescimento "in vitro". As mesmas oito cepas foram logo identificadas e caracterizadas a nível de espécie, devido a sua reatividade frente a um painel de anticorpos monoclonais subgênero e espécie-específicos. Isso foi realizado utilizando o teste de Imunofluorescência Indireta (IFAT/MAbs e de um procedimento de Dot-ELISA. Nós concluímos a partir da análise de serodema dos isolados argentinos que: MHOM/AR/92/SE-1; SE-2; SE-4; SE-8; SE-8-I; SE-30; SE-34 e SE-36 são Leishmania (Viannia braziliensis. Entretanto, três dos isolados de Leishmania (SE-1; SE-2 e SE-30 não foram reconhecidos quando testados com um anticorpo monoclonal de reconhecida alta espécie-especificidade (clone B-18, marcador consagrado de Leishmania (Viannia braziliensis, revelando a existência de dois tipos de serodemas entre as cepas estudadas. Cinco dos oito extratos solúveis de Leishmania foram submetidos à eletroforese em gel de amido de camada fina e subseqüentemente examinadas a fim de constatar a atividade das enzimas MPI, MDH, 6PGD, NH, NH-D, SOD, GPI e ES. Fundamentados nos estudos dos corridos eletroforéticos obtidos nos ensaios isoenzimáticos chegamos à conclusão que as cepas MHOM/AR/92 SE-1; SE-2; SE-4; SE-8 e SE-8-I são Leishmania (Viannia braziliensis. É necessário analisar mais enzimas antes de enquadrá-los nos

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

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Igor A. Rodrigues

2014-01-01

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

IFN-γ, IL-2, IP-10, and MIG as Biomarkers of Exposure to Leishmania spp., and of Cure in Human Visceral Leishmaniasis

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Ana V. Ibarra-Meneses

2017-05-01

Full Text Available New biomarkers are needed for monitoring the effectiveness of treatment for visceral leishmaniasis (VL. They might also improve the detection of the asymptomatic population in Leishmania-endemic areas. This paper examines the IL-2, IFN-γ, IFN-γ-induced protein 10 (IP-10, and monokine-induced-by-IFN-γ (MIG levels in whole blood—stimulated in vitro with soluble Leishmania antigen (SLA—taken from asymptomatic individuals and patients treated for VL living in a post-outbreak (Leishmania infantum area in Spain, and in an endemic (Leishmania donovani area of Bangladesh. IP-10 was found to be an accurate global marker of asymptomatic subjects with positive cellular/humoral tests, while MIG was found to be a better marker of contact with L. donovani than IL-2 but no for those with L. infantum. Determining IP-10, MIG, and IFN-γ levels proved useful in monitoring the cellular immune response following treatment for active disease caused by L. infantum.

Alterações eletromiográficas e histopatológicas da musculatura de cães naturalmente infectados por Leishmania infantum

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Gisela Cristiane Ferraro

2012-10-01

Full Text Available O objetivo do presente estudo foi avaliar as alterações eletromiográficas e histopatológicas de músculos estriados esqueléticos de cães naturalmente infectados por Leishmania infantum. Foram selecionados 25 cães adultos, sem raça definida, com diagnósticos parasitológico, molecular e sorológico estabelecidos para a infecção. Os músculos avaliados foram: tríceps braquial, extensorcarpo radial, bíceps femoral e gastrocnêmio. Um cão possuía problemas locomotores, com paresia de membros posteriores associada à intensa atrofia muscular. Vinte e três (92% apresentavam algum tipo de alteração muscular, sendo que em 22(88% tais alterações foram identificadas diretamente pela eletromiografia. Mesmo sem sinais clínicos, em dez cães (40% foram evidenciadas alterações eletromiográficas e histopatológicas. Antígenos de Leishmania foram identificados na musculatura de quatro (16% cães. Os resultados eletromiográficos indicaram a ocorrência de polimiosite crônica em 13 (52% cães, presença de músculos com inflamação tanto aguda quanto crônica em quatro (16%, miopatia aguda em dois (8%, e ausência de alterações eletromiográficas em três (12%. As alterações histopatológicas mais frequentemente observadas foram degeneração e necrose de miofibras e presença de infiltrado inflamatório verificadas em 12 (48% cães. Outras alterações, quando comparado com as amostras de cães normais, foram do tamanho de grupos de fibras musculares em 15 (60% e fibrose peri ou endomisial em 14(56% animais. As alterações observadas no presente estudo permitiram concluir que mesmo na ausência de sinais clínicos de comprometimento muscular, a maior parte dos cães infectados por L. infantum apresenta polimiosite crônica.

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

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

2016-04-01

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

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

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Kris Régia J. Kondo

2009-08-01

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

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

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Sofía Duque Beltrán

1992-06-01

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

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

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Marcello Ceccarelli

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

Molecular Detection of Leishmania DNA in Wild-Caught Phlebotomine Sand Flies (Diptera: Psychodidae) From a Cave in the State of Minas Gerais, Brazil.

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Carvalho, G M L; Brazil, R P; Rêgo, F D; Ramos, M C N F; Zenóbio, A P L A; Andrade Filho, J D

2017-01-01

Leishmania spp. are distributed throughout the world, and different species are associated with varying degrees of disease severity. In Brazil, Leishmania transmission involves several species of phlebotomine sand flies that are closely associated with different parasites and reservoirs, and thereby giving rise to different transmission cycles. Infection occurs during the bloodmeals of sand flies obtained from a variety of wild and domestic animals, and sometimes from humans. The present study focused on detection of Leishmania DNA in phlebotomine sand flies from a cave in the state of Minas Gerais. Detection of Leishmania in female sand flies was performed with ITS1 PCR-RFLP (internal transcribed spacer 1) using HaeIII enzyme and genetic sequencing for SSUrRNA target. The survey of Leishmania DNA was carried out on 232 pools and the parasite DNA was detected in four: one pool of Lutzomyia cavernicola (Costa Lima, 1932), infected with Le. infantum (ITS1 PCR-RFLP), two pools of Evandromyia sallesi (Galvão & Coutinho, 1939), both infected with Leishmania braziliensis complex (SSUrRNA genetic sequencing analysis), and one pool of Sciopemyia sordellii (Shannon & Del Ponte, 1927), infected with subgenus Leishmania (SSUrRNA genetic sequencing analysis). The present study identified the species for Leishmania DNA detected in four pools of sand flies, all of which were captured inside the cave. These results represent the first molecular detection of Lu cavernicola with Le infantum DNA, Sc sordellii with subgenus Leishmania DNA, and Ev sallesi with Leishmania braziliensis complex DNA. The infection rate in females captured for this study was 0.17%. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Canine antibody response to Phlebotomus perniciosus bites negatively correlates with the risk of Leishmania infantum transmission.

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Michaela Vlkova

2011-10-01

Full Text Available BACKGROUND: Phlebotomine sand flies are blood-sucking insects that can transmit Leishmania parasites. Hosts bitten by sand flies develop an immune response against sand fly salivary antigens. Specific anti-saliva IgG indicate the exposure to the vector and may also help to estimate the risk of Leishmania spp. transmission. In this study, we examined the canine antibody response against the saliva of Phlebotomus perniciosus, the main vector of Leishmania infantum in the Mediterranean Basin, and characterized salivary antigens of this sand fly species. METHODOLOGY/PRINCIPAL FINDINGS: Sera of dogs bitten by P. perniciosus under experimental conditions and dogs naturally exposed to sand flies in a L. infantum focus were tested by ELISA for the presence of anti-P. perniciosus antibodies. Antibody levels positively correlated with the number of blood-fed P. perniciosus females. In naturally exposed dogs the increase of specific IgG, IgG1 and IgG2 was observed during sand fly season. Importantly, Leishmania-positive dogs revealed significantly lower anti-P. perniciosus IgG2 compared to Leishmania-negative ones. Major P. perniciosus antigens were identified by western blot and mass spectrometry as yellow proteins, apyrases and antigen 5-related proteins. CONCLUSIONS: Results suggest that monitoring canine antibody response to sand fly saliva in endemic foci could estimate the risk of L. infantum transmission. It may also help to control canine leishmaniasis by evaluating the effectiveness of anti-vector campaigns. Data from the field study where dogs from the Italian focus of L. infantum were naturally exposed to P. perniciosus bites indicates that the levels of anti-P. perniciosus saliva IgG2 negatively correlate with the risk of Leishmania transmission. Thus, specific IgG2 response is suggested as a risk marker of L. infantum transmission for dogs.

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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Camargo Jiménez Maria Helena; Camacho Maria Marcela

2000-01-01

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

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

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Tania M. Cortázar

2006-10-01

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

Presence of anti-Leishmania (Viannia braziliensis antibodies in blood donors in the West-Central region of the State of Paraná, Brazil

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Lais de Souza Braga

2015-10-01

Full Text Available ABSTRACTINTRODUCTION:Serological screening in blood banks does not include all transmittable diseases. American cutaneous leishmaniasis (ACL has a high detection rate in the municipalities of the State of Paraná.METHODS:This study analyzed the presence of anti- Leishmania braziliensisantibodies in 176 blood donors who live in these endemic areas. The variables were analyzed with the χ2 test and Stata 9.1 software. RESULTS: Twenty (11.4% samples were positive for the presence of anti- L. braziliensisantibodies. CONCLUSIONS: The high percentage of donors with anti- Leishmania spp. antibodies indicates the need to study the risk of ACL transmission through blood donors.

Seroprevalencia de infección por Leptospira spp. en auxiliares y veterinarios de consultorios de pequeños animales de Villavicencio (Colombia

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Helena Quitián

2009-01-01

Full Text Available Objetivo: Determinar seroprevalencia por la prueba de MAT a seis serovares de Leptospira spp. en el grupo de riesgo: auxiliares y veterinarios de consultorios de pequeños animales de Villavicencio, Meta, Colombia, que previamente había sido serorreactor por Elisa-Pambio. Materiales y métodos: Se tomaron 72 muestras de sueros de individuos pertenecientes al subgrupo de auxiliares y veterinarios, de una población mayor que incluía otros 7 grupos humanos a riesgo a Leptospira spp. y que había presentado reactividad serológica considerada como ¿positiva¿ (17 % a la prueba de Elisa para Leptospira spp. con un kit de Pambio. Los sueros, que se habían conservado a -70°C en el Laboratorio de Reproducción y Genética Animal de la Universidad de los Llanos, fueron evaluados para reactividad serológica a la prueba de microaglutinación-lisis (MAT con los serovares L. hardjoprajitno, L. copenhageni, L. canícola, L. icterohaemorrhagiae, L. autumnalis, L. bratislava, L. australis y L. pomona. Se utilizó el protocolo de laboratorio del Programa Nacional de Investigación en Salud Animal de corpoica-ceisa. Resultados: La seropositidad a MAT fue 26.4%. En los auxiliares 21% y los veterinarios 29%. La seropositidad por serovar fue L. bratislava 24%, L. australis 8%, L. copenhageni 6%, L. canícola 3%, L. autumnalis y L. hardjoprajitno 1%. No se encontraron reactores a icterohaemorrhagiae y pomona. Los títulos serológicos estuvieron en un rango entre 1:25 y 1:400. La copositividad entre MAT y ELISA IgM fue 42% y la conegatividad 77%. Conclusiones: La seropositidad en el grupo estudiado es alta y preocupante, por lo tanto, exige extremar las medidas de bioseguridad durante la práctica médico veterinaria.

Native rodent species are unlikely sources of infection for Leishmania (Viannia braziliensis along the Transoceanic Highway in Madre de Dios, Peru.

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Lisa A Shender

Full Text Available An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru's Amazon region, the department of Madre de Dios (MDD rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V. braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%, Hylaeamys perenensis (15.7%, and Proechimys spp. (12%. All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V. braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V. braziliensis transmission to human inhabitants in this highly prevalent region.

Native rodent species are unlikely sources of infection for Leishmania (Viannia) braziliensis along the Transoceanic Highway in Madre de Dios, Peru.

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Shender, Lisa A; De Los Santos, Maxy; Montgomery, Joel M; Conrad, Patricia A; Ghersi, Bruno M; Razuri, Hugo; Lescano, Andres G; Mazet, Jonna A K

2014-01-01

An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru's Amazon region, the department of Madre de Dios (MDD) rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia) braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V.) braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail) were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%), Hylaeamys perenensis (15.7%), and Proechimys spp. (12%). All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V.) braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V.) braziliensis transmission to human inhabitants in this highly prevalent region.

Caracterización de daños producidos por Meloidogyne Spp. (Nemata: Tylenchida en la vid en Mendoza, Argentina

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Carla Vanina Dagatti

2014-12-01

Full Text Available El objetivo de esta investigación fue comparar y establecer relaciones entre los diferentes indicadores de crecimiento entre plantas de vid con dos niveles de infestación (alto y leve de Meloidogyne spp. El estudio se realizó en un viñedo cv Merlot, situado en Agrelo, Mendoza, donde se escogieron 2 parcelas, con y sin nematodos, con diferentes niveles de crecimiento vegetativo. Los indicadores a evaluar fueron: peso y número de racimos por planta, peso de poda, cantidad de entrenudos y área foliar de hojas y feminelas. El grado de infestación de nematodos de cada parcela se determinó mediante la técnica flotación - centrifugación. Para el análisis estadístico se utilizó la prueba de wilcoxon (Mann Whitney U y el test de student. Además, mediante un análisis de regresión lineal, se comprobó si existía relación entre los indicadores evaluados y la densidad de población de Meloidogyne spp. expresado en número de estados juveniles (J2 presentes en el suelo. Los resultados indicaron que la parcela con menor densidad poblacional de juveniles de Meloidogyne spp., presentó mayor peso promedio de madera de poda, así como también un área foliar de hojas y feminelas superior. Con respecto al peso promedio de racimos por planta, dicha parcela también superó a aquella con alta concentración de nematodos.

Aislamiento de genes diferencialmente expresados en amastigotes de Leishmania (Viannia panamensis

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Róbinson Ramírez

2001-04-01

Full Text Available

En Colombia cada año se diagnostican 6.500 casos nuevos de
leishmaniasis cutánea y Leishmania (Viannia panamensis es la responsable del 95% de los casos. Durante su ciclo de vida, el parásito reside en el insecto vector como promastigote y se diferencia a amastigote después de ser inoculado en el hospedero mamífero. La transformación de promastigote a amastigote implica cambios morfológicos y bioquímicos que tienen lugar en el fagolisosoma del macrófago, y se caracterizan, entre otros, por la expresión de enzimas con actividad óptima a pH ácido además del cambio de los glicoconjugados de membrana. La supervivencia del parásito está asociada con su capacidad para inhibir funciones efectoras en el macrófago infectado permitiéndole al amastigote
su replicación; sin embargo, poco se conoce acerca de los productos génicos expresados diferencialmente en este estadio por lo que nos propusimos con este trabajo aislar genes diferencialmente expresados en amastigotes de Leishmania (Viannia panamensis.

Antileishmanial activity and tubulin polymerization inhibition of podophyllotoxin derivatives on Leishmania infantum

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José Miguel Escudero-Martínez

2017-12-01

Full Text Available Leishmania microtubules play an important role not only in cell division, but also in keeping the shape of the parasite and motility of its free-living stages. Microtubules result from the self-assembly of alpha and beta tubulins, two phylogenetically conserved and very abundant eukaryotic proteins in kinetoplastids. The colchicine binding domain has inspired the discovery and development of several drugs currently in clinical use against parasites. However, this domain is less conserved in kinetoplastids and may be selectively targeted by new compounds. This report shows the antileishmanial effect of several series of compounds (53, derived from podophyllotoxin (a natural cyclolignan isolated from rhizomes of Podophyllum spp. and podophyllic aldehyde, on a transgenic, fluorescence-emitting strain of Leishmania infantum. These compounds were tested on both promastigotes and amastigote-infected mouse splenocytes, and in mammalian – mouse non-infected splenocytes and liver HepG2 cells – in order to determine selective indexes of the drugs. Results obtained with podophyllotoxin derivatives showed that the hydroxyl group at position C-7α was a structural requisite to kill the parasites. On regards podophyllic aldehyde, derivatives with C9-aldehyde group integrated into a bicyclic heterostructure displayed more potent antileishmanial effects and were relatively safe for host cells. Docking studies of podophyllotoxin and podophyllic aldehyde derivatives showed that these compounds share a similar pattern of interaction at the colchicine site of Leishmania tubulin, thus pointing to a common mechanism of action. However, the results obtained suggested that despite tubulin is a remarkable target against leishmaniasis, there is a poor correlation between inhibition of tubulin polymerization and antileishmanial effect of many of the compounds tested, fact that points to alternative pathways to kill the parasites. Keywords: Leishmania, Tubulin, DNA

FREQÜÊNCIA DE CÃES INFECTADOS POR Babesia spp. EM CAMPOS DOS GOYTACAZES, RJ FREQUENCY OF DOGS INFECTED BY Babesia spp. IN CAMPOS DOS GOYTACAZES, RJ

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Orlando Augusto Melo JR

2008-04-01

Full Text Available A babesiose canina é transmitida pelo carrapato Rhipicephalus sanguineus e causada por protozoários intra-eritrocitários do gênero Babesia, sendo a B. canis e a B. gibsoni os agentes etiológicos. Comumente há quadros de anemia hemolítica, febre e letargia, anorexia, hematúria e esplenomegalia, com a patogenia relacionada principalmente à multiplicação destes parasitos nas hemácias dos hospedeiros. Tendo em vista a pesquisa de hemoparasitos, no presente trabalho foram realizados exames microscópicos de 2.031 esfregaços sangüíneos delgados, preparados com sangue capilar colhido por perfuração da orelha. Baseou-se o diagnóstico na pesquisa direta, visualizando-se os agentes etiológicos. Trinta cães (1,47% foram considerados infectados por Babesia spp., confirmando, assim, a presença destes parasitos na cidade de Campos dos Goytacazes, onde o clima é favorável ao desenvolvimento do vetor natural
PALAVRAS-CHAVES: Babesia spp., cão, hemoparasito, ocorrência The canine babesiosis is transmitted by the Rhipicephalus sanguineus tick and caused by the intracytoplasmatic protozoa of the Babesia genus, being the B. canis and the B. gibsoni the etiologic agents. Normally there are hemolytic anemia, fever and lethargy, anorexy, hematuria and splenomegaly, with the pathogenesis related mainly to the multiplication of these parasites in the erythrocytes of the hosts. In the present work 2

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

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Washington Luiz Tafuri

1989-06-01

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

Direct detection of Leishmania from clinical samples.

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

2017-01-01

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

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

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Clemencia Elena Ovalle

2006-10-01

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

Frecuencia de aislamiento de Staphylococcus spp meticilina resistentes y Enterococcus spp vancomicina resistentes en hospitales de Cuba Frequency of methicilline-resistant Staphylococcus spp and vancomycin-resistant Enterococcus spp isolates in Cuban hospitals

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Leonora González Mesa

2005-12-01

Full Text Available La resistencia a meticilina en el género Staphylococcus spp es un problema creciente en el ámbito mundial. La producción de una PBP alterada (PBP2a con baja afinidad a betalactámicos, mediada por el gen mec A, es la responsable de esta resistencia. Mientras que los Staphylococcus spp todavía permanecen sensibles a vancomicina, algunos Enterococcus spp han adquirido la capacidad de neutralizar esta droga. En nuestro país no se conocen datos actualizados sobre la tasa de infección por S. aureus meticilina resistente (SAMR, ni sobre la circulación de este germen en la comunidad, tampoco existen reportes de Enterococcus spp vancomicina resistente (EVR. En este estudio fueron analizadas 774 cepas, colectadas en hospitales del país. Se determinó el mecanismo de resistencia utilizando métodos sugeridos por las guías NCCLS. El 9.3 % (23 de los S. aureus aislados en los hospitales y 4.0% (7 S. aureus aislados en la comunidad, fueron SAMR, portadores del gen mec A, el 69.9 % (72 de Staphylococcus coagulasa negativo, fueron resistentes a oxacilina. En la detección del Enterococcus spp vancomicina resistente (EVR, se encontró una cepa portadora de este fenotipo. Nuestros resultados revelan que en nuestro país los SAMR no son un problema en los hospitales, ni en el ambiente comunitario, a pesar de que se reporta por primera vez la circulación de estos en la comunidad y la circulación de EVR en el ambiente hospitalario, su frecuencia es muy baja lo que refleja los avances obtenidos en la aplicación de políticas encaminadas a racionalizar el uso y consumo de antibióticos.Resistance to methicilline in Staphylococcus spp genus is a growing problem worldwide. The production of an altered penicillin-fixing protein with low mecA gen-mediated affinity to beta-lactams is responsible for this resistance. Although Staphylococcus spp still remain susceptible to vancomycin, some Enterococcus spp have acquired the capacity of neutralizing this drug. In

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

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

2013-11-08

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

Lutzomyia migonei is a permissive vector competent for Leishmania infantum.

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Guimarães, Vanessa Cristina Fitipaldi Veloso; Pruzinova, Katerina; Sadlova, Jovana; Volfova, Vera; Myskova, Jitka; Filho, Sinval Pinto Brandão; Volf, Petr

2016-03-17

Leishmania infantum is the most widespread etiological agent of visceral leishmaniasis (VL) in the world, with significant mortality rates in human cases. In Latin America, this parasite is primarily transmitted by Lutzomyia longipalpis, but the role of Lutzomyia migonei as a potential vector for this protozoan has been discussed. Laboratory and field investigations have contributed to this hypothesis; however, proof of the vector competence of L. migonei has not yet been provided. In this study, we evaluate for the first time the susceptibility of L. migonei to L. infantum. Females of laboratory-reared L. migonei were fed through a chick-skin membrane on rabbit blood containing L. infantum promastigotes, dissected at 1, 5 and 8 days post-infection (PI) and checked microscopically for the presence, intensity and localisation of Leishmania infections. In addition, morphometric analysis of L. infantum promastigotes was performed. High infection rates of both L. infantum strains tested were observed in L. migonei, with colonisation of the stomodeal valve already on day 5 PI. At the late-stage infection, most L. migonei females had their cardia and stomodeal valve colonised by high numbers of parasites, and no significant differences were found compared to the development in L. longipalpis. Metacyclic forms were found in all parasite-vector combinations since day 5 PI. We propose that Lutzomyia migonei belongs to sand fly species permissive to various Leishmania spp. Here we demonstrate that L. migonei is highly susceptible to the development of L. infantum. This, together with its known anthropophily, abundance in VL foci and natural infection by L. infantum, constitute important evidence that L. migonei is another vector of this parasite in Latin America.

Obtención de un hidrolizado proteico por fermentación sumergida de plumas utilizando Bacillus spp

OpenAIRE

De Macedo, Manuel; Segura, Roxana; Piñero B., Judith; Coello, Nereida

2009-01-01

Se obtuvo un hidrolizado proteico a partir de la fermentación sumergida de las plumas por una cepa queratinolítica de Bacillus spp designada como LPB-2. El proceso se realizó en condiciones aeróbicas, utilizando un medio salino basal (pH 7,5), suplementado con 20 g/l de plumas molidas y un fermentador de 6 L de capacidad regulado a 40° C durante 26 horas. Mediante alimentaciones semi-continuas de sustrato, efectuadas cada 12 horas, se pudo prolongar el tiempo de fermentación hasta 58 horas. A...

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

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Rafael Góngora

2003-06-01

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

Avaliação da contaminação ambiental por ovos de Ancylostoma spp. em logradouros públicos de Curitiba-Paraná-Brasil / Evaluation of environmental contamination by Ancylostoma spp. eggs in public squares in Curitiba–Paraná State, Brazil

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Luiz Carlos Leite

2011-08-01

Full Text Available O objetivo do trabalho foi avaliar estatisticamente a prevalência de ovos de Ancylostoma spp. em locais públicos e a relevância desses dados, em relação à contaminação ambiental por agentes potenciais de doenças parasitárias, transmissíveis aos animais e ao homem. No sentido de identificar locais que apresentem possíveis riscos de infecções provocadas no homem e animais domésticos por enteroparasitas, foram avaliados trinta logradouros públicos localizados em dezesseis bairros da cidade de Curitiba – Paraná, escolhidos ao acaso para investigação de prevalência da contaminação do solo por ovos de Ancylostoma spp., mediante exames de amostras de fezes de cães, colhidas entre 10 de janeiro e 10 de julho de 2006. Foram recolhidas cinco amostras de fezes em cada um desses locais, num total de cento e cinquenta, posteriormente processadas e analisadas em laboratório através da técnica de sedimentação espontânea. Vinte e uma amostras, recolhidas de dezessete locais, albergavam ovos de Ancylostoma spp. Desse total foram encontradas sete contendo ovos do parasita em fase embrionária.AbstractThe purpose of this study was to evaluate statistically the prevalence of Ancylostoma spp. eggs in public places and the relevance of these data concerning to environmental contamination by parasitical zoonosis. To identificate places that presented possible infection risks to man and domestic animals by enteroparasites, the present study evaluated one hundred fifty samples of dog faces. These samples were collected from thirty public squares in Curitiba, Parana from January 15 to July 15, 2006, and were tested for the presence of Ancylostoma spp. eggs, that can potencially contaminate the soil. From each square it was taken five sampling units of dog feces, that were evaluated by spontaneous sedimentation technique. Twenty one samples recovered of seventheen places had Ancylostoma spp. eggs. Of this total, was found seven with parasite

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

OpenAIRE

Rafael Góngora; Nathalie Acestor; Manfredo Quadroni; Nicolas Fasel; Nancy G. Saravia; John Walker

2003-01-01

En este estudio demostramos el potencial de la electroforesis en dos dimensiones (2DE) como herramienta para la caracterización del proteoma de Leishmania (expresión proteica complementaria del genoma). Los proteomas por 2DE en el rango neutro (pH 5-7) de extractos solubles de promastigotes de Leishmania (Viannia) guyanensis y Leishmania (Viannia) panamensis fueron reproducibles usando tampón de lisis de urea y nonidet P-40. Con la tinción de azul de Coomassie y nitrato de plata se detectaron...

Classificação de lâminas de madeira de Pinus spp. contaminadas por fungos manchadores

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Mayara Elita Carneiro

2013-04-01

Full Text Available A busca por novas tecnologias que garantam a uniformidade da qualidade dos produtos tem se tornado constante, assim este trabalho teve como objetivo estudar a potencialidade de medidas espectroscópicas combinadas a ferramentas estatísticas para classificação de lâminas de madeiras de Pinus spp. contaminadas por fungos manchadores. As amostras foram coletadas em processo industrial, e observou-se que algumas lâminas estavam contaminadas por fungos manchadores. Assim, utilizou-se este material para investigar a influência dessa mancha azul em metodologias espectroscópicas e a possibilidade de discriminação dessa contaminação. Desse material contaminado foram capturados os espectros, na faixa de 400 a 1000 nm. Com esses dados, realizou-se uma análise exploratória por Componentes Principais (PCA e classificação via SIMCA, em que se verificou a discriminação eficiente em dois grupos, madeiras sadias e contaminadas. Observou-se que a técnica de espectroscopia óptica preenche os requisitos necessários para uma possível aplicação na classificação de lâminas no processo produtivo.

Salmonella spp. en niños hospitalizados por enfermedad diarreica: un estudios de casos y controles Salmonella spp. in hospitalized children with diarrheic disease

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Ludy Eunice Jaimes Vivas

1998-02-01

Full Text Available Entre 1988 y 1995 se hicieron 1.468 coprocultivos a niños hospitalizados por enfermedades diarreicas en el Hospital Universitario San Vicente de Paúl, de Medellín; se aisló Salmonella spp. en 324 (22.1%. El objetivo del presente estudio fue identificar los factores asociados con la presencia de Salmonella spp. Para ello se compararon las características de los niños con coprocultivo positivo para Salmonella spp. Con las de aquéllos en quienes el resultado fue negativo, mediante la determinación de la razón de disparidad con intervalos de confianza del 95%. Se encontró asociación estadísticamente significativa entre la presencia de Salmonella spp. Y la edad comprendida entre uno y doce meses: Razón de disparidad (RD 1.63 (intervalo de confianza de195% (IC 95% 1.24-2.14; la diarrea persistente, RD 1.45 (IC 95% 1.09-1.9.3; la disentería: RD 2.25 (IC 95% 1.61-3.15; la utilización previa de antibióticos: RD 1.40 (IC 95% 1.08- 1.80; la presencia de leucocitos y eritrocitos abundantes en el examen directo de materias fecales: RD 2.07 (IC 95% 1.53-2.79 y RD 1.94 (IC 95% 1.34-2.82, respectivamente. Se encontró asociación negativa estadísticamente significativa entre la presencia de Salmonella spp. y la edad comprendida entre doce y veinticuatro meses, RD: 0.62 (IC 95% 0.45-0.84 y con la duración de la diarrea de menos de cuatro días: RD 0.64 (IC 95% 0.46-0.88. Between 1988 and 1995, 1468 s,rool cultures were performed in children hosplfalized with diarrheic disease, at a University Hospital in Medellín, Colombia. Salmonella spp was isolated from 324 (22.1%. Positive and negative children were compared: Significant associations were found between the presence of Salmonella and the following characteristics: Age between 1 and 12 months (Odds Ratio 1.63; persistent diarrhea (OR 1.45; disentery (OR 2.25; previous use of antibiotics (OR 1.4; presence of abundant white or red blood cells in stools on direct examination (OR 2.07 and 1

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

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Flávio França

1996-06-01

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

Gluconeogenesis in Leishmania mexicana

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Rodriguez-Contreras, Dayana; Hamilton, Nicklas

2014-01-01

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

Diagnóstico da infecção por Bartonella spp.: a propósito de um caso de angiomatose bacilar Diagnosis of Bartonella spp. infection: study of a bacillary angiomatosis case

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Paulo Eduardo Neves Ferreira Velho

2006-08-01

Full Text Available Várias dermatoses são consideradas idiopáticas. Muitas vezes, afecções como eritema nodoso ou eritema multiforme, por exemplo, não podem ter sua etiologia definida. A infecção humana por Bartonella spp. pode determinar várias expressões clínicas sindrômicas. A partir de um caso de angiomatose bacilar com documentação clínica, histológica e ultra-estrutural, foi feita a revisão da literatura médica para avaliar os critérios diagnósticos disponíveis para a infecção por esses agentes. Conclui-se que a avaliação histológica é, na prática, um importante e útil método diagnóstico, especialmente quando a sorologia não estiver disponível.Several dermatoses are considered idiopathic diseases. Many times lesions such as erythema nodosum or erythema multiformis, for example, cannot have their etiology defined. Human infection caused by Bartonella spp. may determine several clinical syndromic expressions. Starting with a clinically, histologically and ultrastructurally documented bacillary angiomatosis case, a review of medical literature was undertaken to evaluate the available diagnostic criteria regarding infection caused by these agents. Histological evaluations were concluded to be, practically speaking, an important and useful diagnostic method, especially when serology is not available.

Molecular detection and identification of Leishmania spp. in naturally infected Phlebotomus tobbi and Sergentomyia dentata in a focus of human and canine leishmaniasis in western Turkey.

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Özbel, Yusuf; Karakuş, Mehmet; Arserim, Suha K; Kalkan, Şaban Orçun; Töz, Seray

2016-03-01

Human visceral leishmaniasis (VL) is reported from 38 provinces of Turkey and dogs are accepted as main reservoir hosts. Kuşadası town, belonging to Aydın province and located in western part of Turkey, is endemic for human and canine visceral leishmaniasis caused by Leishmania infantum MON1 and MON98. In this study, phlebotomine survey was conducted to determine the vector sand fly species and to identify sand fly blood meal sources. In August and September 2012, 1027 sand fly specimens were caught using CDC light traps. Eight Phlebotomus and two Sergentomyia species with the dominancy of Phlebotomus tobbi (61.34%) were detected. A total of 622 female sand flies (571 Phlebotomus; 51 Sergentomyia) were checked for Leishmania infection by direct dissection of the midgut. The half of the midgut content was inoculated into NNN culture for isolation of the parasite. Leishmania species-specific ITS1 real time PCR, conventional PCR assays of ITS1 and hsp70 genes and subsequent sequencing were performed from extracted DNAs. A region of cytochrome b (cyt-b) gene of vertebrates based PCR was used to determine the source of blood meal of sand flies. In microscopical examinations, two female specimens (0.32%) were found naturally infected with high number and different stages of promastigotes. No growth was observed in NNN culture but Leishmania DNA was obtained from both specimens. First positive specimen was identified as P. tobbi and L. infantum DNA was detected. Second specimen was Sergentomyia dentata, but Leishmania DNA could not be identified on species level. A total of 16 blood-fed female P. tobbi specimens were used for blood meal analysis and eight, three and one specimens were positive for human, dog and mouse, respectively. This is the first detection of Leishmania promastigotes using microscopical examination in P. tobbi and S. dentata in human and canine visceral leishmaniasis endemic area in western part of Turkey. Our results indicate that, (i) P. tobbi is

Comparison of small mammal prevalence of Leishmania (Leishmania mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico Comparación de las prevalencias de Leishmania (Leishmania mexicana en mamíferos pequeños en cinco focos de leishmaniosis cutánea en el estado de Campeche, México

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N.R. Van Wynsberghe

2009-04-01

Full Text Available In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March. One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L. mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L. mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004 in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.En la Península de Yucatán, México, la Leishmaniosis Cutánea es causada por Leishmania (L. mexicana en 95% de los casos humanos, con una incidencia de 5.08% por cada 100,000 habitantes. El ciclo de transmisión se limita a la estación de invierno (noviembre- marzo. Un estudio de mamíferos silvestres incrimina a Ototylomys phyllotis y Peromyscus yucatanicus como reservorios primarios de L. (L. mexicana en el foco de infección de La Libertad, Campeche. En el presente estudio, se documenta la prevalencia de infección/enfermedad causada por L. (L. mexicana en pequeños mamíferos, durante cinco estaciones de transmisión (1994-2004 en cinco focos de CL del estado de Campeche. Los focos separados por solamente 100 km. de distancia, aún cuando tienen abundancias relativas de pequeños roedores similares, fueron significativamente diferentes en relación a la prevalencia de síntomas así como de

Members of a large retroposon family are determinants of post-transcriptional gene expression in Leishmania.

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Frédéric Bringaud

2007-09-01

Full Text Available Trypanosomatids are unicellular protists that include the human pathogens Leishmania spp. (leishmaniasis, Trypanosoma brucei (sleeping sickness, and Trypanosoma cruzi (Chagas disease. Analysis of their recently completed genomes confirmed the presence of non-long-terminal repeat retrotransposons, also called retroposons. Using the 79-bp signature sequence common to all trypanosomatid retroposons as bait, we identified in the Leishmania major genome two new large families of small elements--LmSIDER1 (785 copies and LmSIDER2 (1,073 copies--that fulfill all the characteristics of extinct trypanosomatid retroposons. LmSIDERs are approximately 70 times more abundant in L. major compared to T. brucei and are found almost exclusively within the 3'-untranslated regions (3'UTRs of L. major mRNAs. We provide experimental evidence that LmSIDER2 act as mRNA instability elements and that LmSIDER2-containing mRNAs are generally expressed at lower levels compared to the non-LmSIDER2 mRNAs. The considerable expansion of LmSIDERs within 3'UTRs in an organism lacking transcriptional control and their role in regulating mRNA stability indicate that Leishmania have probably recycled these short retroposons to globally modulate the expression of a number of genes. To our knowledge, this is the first example in eukaryotes of the domestication and expansion of a family of mobile elements that have evolved to fulfill a critical cellular function.

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

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Elsy Nalleli Loría-Cervera

2013-04-01

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

Detection of Leishmania RNA virus in Leishmania parasites.

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Haroun Zangger

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

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

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

2017-02-01

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

Detecção de oocistos de Cryptosporidium spp. e cistos de Giardia spp. em amostras de esgoto bruto ou tratado: avaliação crítica dos métodos Detection of Cryptosporidium spp. oocysts and Giardia spp. cysts in raw and effluent wastewater: critical evaluation of methods

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Luciana Urbano dos Santos

2011-06-01

Full Text Available Neste trabalho, avaliou-se a eficiência dos métodos centrífugo-concentração e filtração em membrana, na detecção de oocistos de Cryptosporidium spp. e cistos de Giardia spp. em amostras de esgoto bruto e tratado, provenientes de um sistema de lodos ativados (estação de tratamento de esgoto, Samambaia, Campinas, em São Paulo. As amostras foram coletadas quinzenalmente por dois anos: 53 amostras de esgoto bruto (AFL, 53 de efluente tratado sem desinfecção por luz ultravioleta (EFL e 38 de efluente tratado e desinfetado por luz ultravioleta (EFL+UV. Cistos de Giardia spp. foram encontrados em 90,5% das amostras AFL; em 96,2%, de EFL; e em 94,7%, de EFL+UV. Oocistos de Cryptosporidium spp. foram detectados em 6,4% das amostras AFL e em 2,6 % de EFL+UV. Ambos os métodos mostraram-se eficientes na detecção destes protozoários em todos os tipos de amostras, além de apresentarem baixo custo por análise.In this study, the efficiency of centrifuge-concentration and membrane filtrated methods was evaluated in the detection of Cryptosporidium spp. oocysts and Giardia spp. cysts in raw or treated wastewater samples, from activated sludge systems (ETE - Samambaia, Campinas, in São Paulo. The samples were collected once a fortnight for two years: 53 samples of influent (AFL, 53 samples of treated effluent without ultraviolet disinfection (EFL, and 38 samples of treated effluent with ultraviolet disinfection (EFL+UV. Giardia spp. cysts were found in 90.5% of the AFL samples; in 96.2% of the samples, EFL; and in 94.7%, EFL+UV. Cryptosporidium spp. oocysts were detected in 6.4% of AFL samples and 2.6% of EFL+UV. Both methods showed efficiency when detecting protozoa in all types of samples, besides having low costs by analysis.

Mortalidade de Coccus viridis (Hemiptera: Coccidae por Lecanicillium spp. em diferentes órgãos de Coffea arabica

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Flávio Lemes Fernandes

2009-04-01

Full Text Available Objetivou-se neste trabalho avaliar a mortalidade de Coccus viridis por Lecanicillium spp. em folhas e ramos de Coffea arabica. O trabalho foi realizado na casa de vegetação na Universidade Federal de Viçosa, entre fevereiro de 2005 a junho de 2006. Foram utilizadas sementes da variedade Catuaí vermelho de café (C. arabica. A solução nutritiva utilizada foi composta por 3,0 mmol/L de N, 9,0 mmol/L de K, 1,0 mmol/L de P, 4,0 mmol/L de Ca, 2,1 mmol/L de S, 46 µmol/L de B, 0,3 µmol/L de Cu, 60,0 µmol/L de Fe, 2,0 µmol/L de Mg, 0,5 µmol/L de Mo e 36,0 µmol/L de Mn. As cochonilhas e o fungo foram coletados de folhas de café em lavouras comerciais de Viçosa, MG e foram mantidos em gaiolas em Casa de Vegetação. As plantas foram infestadas com oito meses de idade. A infestação foi realizada por contato de C. viridis infectadas com o fungo sobre as cochonilhas sadias. As densidades de C. viridis viva e morta nas folhas e nos ramos foram avaliadas aos 0, 15, 30, 35, 45, 60 e 75 dias após a infestação. Usou-se análise de variância, teste de média de Skott-Knott e análise de regressão linear simples a p<0,05. O fungo Lecanicillium spp. causou mortalidade em todos os estádios de C. viridis. De forma geral, a maior mortalidade ocorreu no terceiro ínstar. Além disso, o fungo causou maior mortalidade nesse inseto praga na face abaxial da folha de café. Mortality of Coccus viridis (Hemiptera: Coccidae by Lecanicillium spp. in differents Coffea arabica organs in greenhouseAbstract. The objective of this work was to evaluate the mortality of Coccus viridis by Lecanicillium spp. on faces of the leaves, and branches of Coffea arabica. This work was conducted in greenhouse at UFV. The experiment was carried out from February 2005 to June 2006. Seeds of the lineage IAC 15 from the variety “Catuaí Vermelho” coffee (C. arabica were used. The nutritive solution utilized was composed for 3. 0 mmol/L of N, 9. 0 mmol/L of K, 1. 0 mmol

Classificação de lâminas de madeira de Pinus spp. contaminadas por fungos manchadores Classification of Pinus spp. veneers wood contaminated by blue stain fungi

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Mayara Elita Carneiro

2013-04-01

Full Text Available A busca por novas tecnologias que garantam a uniformidade da qualidade dos produtos tem se tornado constante, assim este trabalho teve como objetivo estudar a potencialidade de medidas espectroscópicas combinadas a ferramentas estatísticas para classificação de lâminas de madeiras de Pinus spp. contaminadas por fungos manchadores. As amostras foram coletadas em processo industrial, e observou-se que algumas lâminas estavam contaminadas por fungos manchadores. Assim, utilizou-se este material para investigar a influência dessa mancha azul em metodologias espectroscópicas e a possibilidade de discriminação dessa contaminação. Desse material contaminado foram capturados os espectros, na faixa de 400 a 1000 nm. Com esses dados, realizou-se uma análise exploratória por Componentes Principais (PCA e classificação via SIMCA, em que se verificou a discriminação eficiente em dois grupos, madeiras sadias e contaminadas. Observou-se que a técnica de espectroscopia óptica preenche os requisitos necessários para uma possível aplicação na classificação de lâminas no processo produtivo.The search for new technologies that ensure uniformity of product quality has become constant. The objective of this work was to study the potential of spectroscopic measurements combined with statistical tools for sorting sheets of wood of Pinus spp. contaminated by staining fungi. Samples were collected in the industrial process and it was found that some blades were contaminated by fungus staining. Thus, this material was used to investigate its influence on blue stain and spectroscopic methods and the possibility of discrimination by such contamination. Spectra at 400-1000 m range were captured from this contaminated material. By using these data, it was performed an exploratory analysis by Principal Components (PCA and classification via SIMCA, where discrimination was found effective in healthy and diseased wood. It is observed that the use of

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

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

2017-08-01

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

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

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Sarah Athayde Couto Falcão

2016-08-01

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

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

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Jazzmín Arrivillaga-Henríquez

2017-03-01

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

Genetic Diversity and Phylogenetic Analysis of the Iranian Leishmania Parasites Based on HSP70 Gene PCR-RFLP and Sequence Analysis.

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Nemati, Sara; Fazaeli, Asghar; Hajjaran, Homa; Khamesipour, Ali; Anbaran, Mohsen Falahati; Bozorgomid, Arezoo; Zarei, Fatah

2017-08-01

Despite the broad distribution of leishmaniasis among Iranians and animals across the country, little is known about the genetic characteristics of the causative agents. Applying both HSP70 PCR-RFLP and sequence analyses, this study aimed to evaluate the genetic diversity and phylogenetic relationships among Leishmania spp. isolated from Iranian endemic foci and available reference strains. A total of 36 Leishmania isolates from almost all districts across the country were genetically analyzed for the HSP70 gene using both PCR-RFLP and sequence analysis. The original HSP70 gene sequences were aligned along with homologous Leishmania sequences retrieved from NCBI, and subjected to the phylogenetic analysis. Basic parameters of genetic diversity were also estimated. The HSP70 PCR-RFLP presented 3 different electrophoretic patterns, with no further intraspecific variation, corresponding to 3 Leishmania species available in the country, L. tropica, L. major, and L. infantum. Phylogenetic analyses presented 5 major clades, corresponding to 5 species complexes. Iranian lineages, including L. major, L. tropica, and L. infantum, were distributed among 3 complexes L. major, L. tropica, and L. donovani. However, within the L. major and L. donovani species complexes, the HSP70 phylogeny was not able to distinguish clearly between the L. major and L. turanica isolates, and between the L. infantum, L. donovani, and L. chagasi isolates, respectively. Our results indicated that both HSP70 PCR-RFLP and sequence analyses are medically applicable tools for identification of Leishmania species in Iranian patients. However, the reduced genetic diversity of the target gene makes it inevitable that its phylogeny only resolves the major groups, namely, the species complexes.

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

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

2005-07-01

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

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

International Nuclear Information System (INIS)

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

2005-01-01

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

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

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É. Labat

2010-06-01

Full Text Available Avaliaram-se alterações espermáticas associadas à infecção por leishmaniose no sêmen de cães naturalmente infectados, utilizando-se, durante oito semanas consecutivas, ejaculados de seis cães soronegativos e seis cães soropositivos. As amostras foram colhidas uma vez por semana e avaliadas quanto ao volume, concentração, motilidade, vigor, morfologia espermática, integridade da cromatina, avaliação simultânea da integridade da membrana plasmática, acrossoma e potencial mitocondrial. Concomitantemente foram dosadas a proteína total do plasma seminal e sanguíneo. A leishmaniose visceral causou aumento dos defeitos maiores e menores nos espermatozoides dos animais acometidos pelo estágio moderado a severo da doença. Em estágios mais avançados da enfermidade, a integridade das membranas acrossomal e plasmática foi afetada negativamente. Não foi possível estabelecer um critério quanto à avaliação do potencial mitocondrial. A incidência de alterações morfológicas nos animais acometidos não promoveu aumento de injurias à cromatina. Todos os animais com leishmaniose apresentaram hiperproteinemia do sêmen.The spermatic changes associated with the natural infection in dogs by Leishmania sp was evaluated during eight consecutive weeks, using ejaculates of six seronegative and six seropositive dogs. The samples were collected once a week and evaluated for volume, concentration, motility, vigor, sperm morphology, chromatin integrity, simultaneous evaluation of the plasmatic membrane integrity, acrosome, and mitochondrial potential. The total proteins of the seminal plasma and blood were measured. The visceral leishmaniasis caused increase of major and minor defects in spermatozoa of animals attacked by moderate to severe stages of the disease. In more advanced stages of the illness, the acrosomal and plasmatic membranes integrity was adversely affected. It was not possible to establish a pattern refering the evaluation of

Nuclear DNA replication and repair in parasites of the genus Leishmania: Exploiting differences to develop innovative therapeutic approaches.

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Uzcanga, Graciela; Lara, Eliana; Gutiérrez, Fernanda; Beaty, Doyle; Beske, Timo; Teran, Rommy; Navarro, Juan-Carlos; Pasero, Philippe; Benítez, Washington; Poveda, Ana

2017-03-01

Leishmaniasis is a common tropical disease that affects mainly poor people in underdeveloped and developing countries. This largely neglected infection is caused by Leishmania spp, a parasite from the Trypanosomatidae family. This parasitic disease has different clinical manifestations, ranging from localized cutaneous to more harmful visceral forms. The main limitations of the current treatments are their high cost, toxicity, lack of specificity, and long duration. Efforts to improve treatments are necessary to deal with this infectious disease. Many approved drugs to combat diseases as diverse as cancer, bacterial, or viral infections take advantage of specific features of the causing agent or of the disease. Recent evidence indicates that the specific characteristics of the Trypanosomatidae replication and repair machineries could be used as possible targets for the development of new treatments. Here, we review in detail the molecular mechanisms of DNA replication and repair regulation in trypanosomatids of the genus Leishmania and the drugs that could be useful against this disease.

Contamination of public parks in Presidente Prudente (São Paulo, Brazil by Toxocara spp. eggs Contaminação de praças públicas de Presidente Prudente, São Paulo, Brasil, por ovos de Toxocara spp

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Vamilton Alvares Santarém

2012-09-01

Full Text Available This study aims to evaluate soil contamination by Toxocara spp. eggs in public parks in Presidente Prudente, São Paulo, Brazil. Soil samples (500 g were collected every month over a 12-month period, from 25 parks in different parts of the city (northern, southern, eastern, western and central areas. Two 10-g aliquots of the material collected from each park were subjected to the centrifuge-flotation method to recover Toxocara spp. eggs. Twenty-four out of the 25 squares studied (96.0% were contaminated and the number of eggs recovered ranged from 1 to 398 per sample. Eggs were recovered all over the year. Despite the number being greater in autumn (p O objetivo do estudo foi avaliar a contaminação do solo de praças públicas por ovos de Toxocara spp. em Presidente Prudente, São Paulo. Amostras de solo (500 g foram coletadas mensalmente, durante um período de 12 meses, de 25 praças de cinco diferentes setores da cidade (norte, sul, leste, oeste e central. Duas alíquotas de 10 g do material coletado foram submetidas ao método de centrífugo-flutuação (sulfato de zinco; d = 1.200 g/cm³, para recuperação dos ovos. Das 25 praças estudadas, 24 (96,0% estavam contaminadas e o número variou de 1 a 398 ovos por amostra analisada. A recuperação foi verificada durante todos os meses do ano, sendo maior no outono (p < 0,001. Entretanto, não houve correlação entre o número de ovos e a temperatura média (r = -0,492; p = 0,148 e a precipitação pluviométrica (r = -0,299; p = 0,402 mensal. Não houve influência da localização dos parques sobre a quantidade de ovos (p = 0,7116. Devido ao alto nível de contaminação de parques públicos por ovos de Toxocara spp., a prevenção da contaminação de áreas públicas pelos agentes de larva migrans é indicada.

Accuracy of qPCR for quantifying Leishmania kDNA in different skin layers of patients with American tegumentary leishmaniasis.

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Sevilha-Santos, L; Dos Santos Júnior, A C M; Medeiros-Silva, V; Bergmann, J O; da Silva, E F; Segato, L F; Arabi, A Y M; de Paula, N A; Sampaio, R N R; Lima, B D; Gomes, C M

2018-05-03

Superficial swab sampling of American tegumentary leishmaniasis (ATL) lesions shows higher amounts of Leishmania than those from biopsy. Subcutaneous involvement is also important in ATL, but parasite quantification according to lesion depth has not been evaluated. We aim to present the best depth at which sampling should be performed for molecular exams of ATL. Patients with a clinical presentation compatible with ATL were allocated to ATL and control groups. Qualitative and quantitative qPCR assays were performed using SYBR Green and primers amplifying the kDNA minicircle of Leishmania spp. in different skin layers, including the epidermis, the superior dermis, the inferior dermis, and the hypodermis. Fifty-nine patients were included in this study, including 40 who had been diagnosed with ATL and 19 controls. The number of parasites was greater in samples of the epidermis and superior dermis (159.1 × 10 6 , range 4.0-781.7, and 75.4 × 10 6 , range 8.0-244.5, mean Leishmania parasite equivalents per μg of tissue DNA, respectively) than those in samples of the inferior dermis and hypodermis (54.6, range 8.0-256.6, and 16.8 × 10 6 , range 8.0-24.1, mean Leishmania parasite equivalents per μg of tissue DNA, respectively). The best diagnostic accuracy was achieved in the superior dermis (77.9%) and was significantly greater than that in the hypodermis (63.3%; p 0.039). We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

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Ítalo A. Sherlock

1972-02-01

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

Molecular identification of Leishmania species in Taybad district, Iran

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Salehi Ghodratollah

2014-09-01

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

Innate Immunity against Leishmania Infections

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Gurung, Prajwal; Kanneganti, Thirumala-Devi

2015-01-01

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

Apagando genes para iluminar la interacción entre el macrófago y Leishmania

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Carlos Arturo Clavijo-Ramirez

2016-02-01

Full Text Available La enfermedad causada por los parásitos del género Leishmania representa un problema de salud pública de importancia a nivel nacional e internacional. El conocimiento actual de la interacción entre el macrófago humano y el parásito aún luce insuficiente para reflejarse en mejoras del tratamiento empleado. El presente manuscrito aspira a ser un texto de divulgación para el púbico general y trata de explicar la importancia de este tipo de investigación científica y la estrategia empleada por nuestro grupo de investigación, en la búsqueda de soluciones al flagelo representado por los diferentes tipos de Leishmaniasis.

Actividad contra Leishmania sp. (Kinetoplastida: Trypanosomatidae) de plantas en una Reserva Biológica de Costa Rica

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Misael Chinchilla-Carmona; Idalia Valerio-Campos; Ronald Sánchez-Porras; Vanessa Bagnarello-Madrigal; Laura Martínez-Esquivel; Antonieta González-Paniagua; Javier Alpizar-Cordero; Maribel Cordero-Villalobos; Daniela Rodríguez-Chaves

2014-01-01

La leishmaniosis es una enfermedad muy importante para el ser humano pero su tratamiento es bastante difícil. Por esta razón muchos investigadores han venido buscando plantas que contengan componentes químicos activos contra esta parasitosis. En Costa Rica no se tienen estudios al respecto y por eso el objetivo de este estudio fue la búsqueda de componentes activos contra Leishmania sp. en plantas de Costa Rica; 67 especies de la Reserva Biológica Alberto Manuel Brenes (REBAMB) fueron selecci...

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

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

2017-01-01

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

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

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César Augusto Cuba-Cuba

1991-10-01

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

Phylogenomic reconstruction supports supercontinent origins for Leishmania.

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

2016-03-01

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

Screening for Inhibitors of Essential Leishmania Glucose Transporters

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2013-07-01

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

Celulitis por Microascus trigonosporus(anamorfo Scopulariopsis trigonospora

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DELIA CANLE CORTIÑAS

2013-06-01

Full Text Available Resumen: Microascus trigonosporus ( anamorfo Scopulariopsis trigonospora es un hongo filamentoso ubicuo que se encuentra en el suelo , plumas de aves, material vegetal e insectos. Aunque Scopulariopsis spp se consideran comúnmente hongos contaminantes , pueden causar ocasionalmente infecciones en humanos, en especial onicomicosis . Excepcionalmente se han descrito infecciones de piel, abscesos cerebrales, endocarditis ,sinusitis e infecciones diseminadas por Scopulariopsis spp , casi siempre en pacientes inmunodeprimidos . En los últimos años se han publicado un mayor número de casos de infecciones oportunistas por Scopulariopsis spp y otros hialohifomicetos multiresistentes. Todavía no está establecido cuál es el mejor régimen de tratamiento para las infecciones por Scopulariopsis spp. Presentamos un caso excepcional de celulitis por Microascus trigonosporus en un paciente con tratamiento prolongado con corticoides. Abstract: Microascus trigonosporus ( Anamorph Scopulariopsis trigonospora is a cosmopolitan filamentous fungus that inhabits soil, feathers ,plant material and insects. While Scopulariopsis is commonly considered as a contaminat fungus it may cause occasionally infections in humans ,especially onychomycosis .Skin lesions, brain abscess , endocarditis, sinusitis and disseminated infections due to Scopulariopsis species have been rarely reported , usually in immunocompromised patients . Over the last few years opportunistic infections by Scopulariopsis species and others multi-resistant hyalohyphomycetes have been increasingly reported . No clear treatment regimen for Scopulariopsis species infections has been established yet. We present a exceptional case of cellulitis due to Microascus trigonosporus in a patient with prolonged steroid therapy.

PCR associated with hybridization with DNA radioactive probes for diagnosis of asymptomatic infection caused by Leishmania Chagasi; PCR associado a hibridizacao com sondas radioativas de DNA para a identificacao de infeccao subclinica causada por Leishmania Chagasi

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Andrade, Antero Silva Ribeiro de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Moreno, Elizabeth Castro [Fundacao Nacional de Saude, Belo Horizonte, MG (Brazil). Coordenacao Regional de Minas Gerais; Gomes, Rosangela Fatima; Melo, Maria Norma de; Carneiro, Mariangela [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Parasitologia; Fernandes, Octavio [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept. de Medicina Tropical

2002-07-01

Detection systems for diagnosis of leishmaniasis based on PCR are very promising due to their sensitivity and specificity. Secondary detection by specific radioactive DNA probes, able to type the PCR amplified products, increase the specificity and raise about tem-fold the sensitivity of the assay. The aim of this work was evaluate PCR and hybridization as a tool to identify Leishmania (Leishmania) chagasi (the specie that cause the visceral leishmaniasis in Brazil) infection in asymptomatic persons living in a endemic area. Material and Methods: A group of 226 asymptomatic individuals, living in General Carneiro (MG), was selected. Blood samples were harvested and the DNA extracted from the mononucleate cells. PCR was performed using primers addressed to the kinetoplast DNA minicircles. This protocol gives a positive reaction for all Leishmania species. The amplified products were further hybridized with cloned L.chagasi minicircles labeled with {sup 32} P. Results: were identified 111 samples PCR positive, 2 of them hybridization negative and 133 samples hybridization positive, 24 of them PCR negative. The occurrence of samples with hybridization positive and PCR negative was expected since hybridization, with DNA probes labeled with {sup 32} P, increase the sensitivity of the assay. The samples that presented positive PCR and negative hybridization were probably due the presence of other Leishmania species, likely L. (V.) braziliensis (that produce tegumentary leishmaniasis in the region), since L. (L.) chagasi cloned minicircles were used as hybridization probe. We conclude that this procedure is a valuable tool to access subclinical L. (L.) chagasi infections in epidemiological studies. (author)

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

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

2018-03-15

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

Ciclo de vida y colonización de Lutzomyia ovallesi (Diptera: Psychodidae, vector de Leishmania spp. en América Latina

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Olga L. Cabrera

1999-09-01

Full Text Available Lutzomyia ovallesi (Diptera: Psychodidae, presente en un foco de Leishmania (V braziliensis en Reventones, Cundinamarca, reg- ión ubicada en el centro de Colombia. se crió y mantuvo por catorce generaciones bajo condiciones de laboratorio con una temperatura diaria entre 22-28 ""C y una humedad relativa entre 90 y 98%. Después de la emergencia, se llevaron machos y hembras a vasos de poliestireno (transparente y se mantuvieron en una nevera de icopor. La duración de cada uno de los estadios del ciclo de vida observado en las crías individuales fue: huevo 9-12 días (X = 10, 42, DE = 0,86; larva 17-11 días (X=9,9, DE=3,06; larva 11 7-13 días (X=9,5, DE= 3,06; larva III 4-12 (X=7,4, DE=1,50; larva IV 9-19 días (X=15,16, DE=2,66 y pupa 8-16 días (X=11, DE=1,89. El tiempo promedio para el desarrollo total del ciclo biológico fue de 63,36 días. La longevidad para las hembras presentó un rango entre 5 y 10 días (X=9,36 y para los machos entre 4 y 13 días (X=7,44. Con respecto a la productividad registrada a partir de un promedio de 30 hembras de Lutzomyia por vaso de cría, se obtuvo una producción mínima de 260 flebótomos en la quinta generación y una máxima de 4.51 1 en la décimotercera generación.

Leishmania infections: Molecular targets and diagnosis.

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

2017-10-01

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

Improvement of the green fluorescent protein reporter system in Leishmania spp. for the in vitro and in vivo screening of antileishmanial drugs.

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Pulido, Sergio A; Muñoz, Diana L; Restrepo, Adriana M; Mesa, Carol V; Alzate, Juan F; Vélez, Iván D; Robledo, Sara M

2012-04-01

Development of new therapeutic approaches for leishmaniasis treatment requires new high throughput screening methodologies for the antileishmanial activity of the new compounds both in vitro and in vivo. Reporter genes as the GFP have become one of the most promissory and widely used tools for drug screening in several models, since it offers live imaging, high sensibility, specificity and flexibility; additionally, the use of GFP as a reporter gene in screening assays eliminates all the drawbacks presented in conventional assays and also those technical problems found using other reporter genes. The utility of the GFP as a reporter gene in drug screening assays with Leishmania parasites depends on the homogeneity and stability of the GFP transfected strains. Stable expression of the GFP in the Old World Leishmania species has been demonstrated using integration vectors; however, no reports exist yet about the success of this methodology in the New World species. Here we report the generation of New World Leishmania strains expressing the GFP protein from an integration vector, which replaces one copy of the 18S RNA in the chromosome with the GFP coding sequence by homologous recombination. We also prove that the expression of the integrated GFP is stable and homogeneous in the transfected parasites after months in culture without selective pressure or during its use in hamster infection assays. The fluorescent strains are useful for in vitro, ex vivo and in vivo drug screening assays since no considerable variations in virulence or infectivity where seen attributable to the genetic manipulation during both in vitro and in vivo infection experiments. The platform described here for drug testing assays based on the use of stable fluorescent Leishmania strains coupled to flow cytometry and fluorescent microscopy is more sensitive, more specific and faster than conventional assays used normally for the evaluation of compounds with potential antileishmanial activity

Infecciones por bacterias poco comunes y oncogénesis bacteriana

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Horacio A. Lopardo

Full Text Available La recuperación de algunos microorganismos de aislamiento esporádico en el laboratorio de microbiología clínica podría significar la existencia de algún defecto inmunitarioespecial en el paciente. Por ejemplo, se ha descrito una importante correlación entre Clostridium septicum y carcinoma de colon, y se han visto relacionadas con leucemias y linfomas a especies que aparecen casi siempre como contaminantes (Bacillus spp., Corynebacterium spp. y a otras raramente aisladas en otros contextos (Capnocytophaga spp.. Hay bacterias que se aíslan casi exclusivamente de pacientes con sida (Rhodococcus equi. Se ha observado una mayor frecuencia de infecciones por Campylobacter spp., Aeromonas spp. y estreptococos del grupo G y del grupo mitis en individuos con algún tipo de cáncer que en el resto de los pacientes. También hay bacterias que son marcadoras de algún cáncer no detectado o que afectan más a pacientes neutropénicos que a individuos normoinmunes. La alteración de la reacción inflamatoria, la linfoproliferación mediada por antígenos bacterianos y la inducción de hormonas que aumentan la proliferación de las células epiteliales podrían ser causas de la oncogénesis bacteriana. Los ejemplos clásicos son el adenocarcinoma gástrico inducido por Helicobacter pylori, la asociación de la bacteriemia por estreptococos del grupo bovis y el cáncer de colon y los linfomas de tejido linfoide asociado a mucosas (MALT en vinculación con especies de Helicobacter (MALT gástricos y con Chlamydophila spp. (MALT oculares. El aislamiento de alguno de estos patógenos debería ser un llamado de atención para inducir al estudio de alguna enfermedad maligna.

Leishmania infantum Asparagine Synthetase A Is Dispensable for Parasites Survival and Infectivity.

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Faria, Joana; Loureiro, Inês; Santarém, Nuno; Macedo-Ribeiro, Sandra; Tavares, Joana; Cordeiro-da-Silva, Anabela

2016-01-01

A growing interest in asparagine (Asn) metabolism has currently been observed in cancer and infection fields. Asparagine synthetase (AS) is responsible for the conversion of aspartate into Asn in an ATP-dependent manner, using ammonia or glutamine as a nitrogen source. There are two structurally distinct AS: the strictly ammonia dependent, type A, and the type B, which preferably uses glutamine. Absent in humans and present in trypanosomatids, AS-A was worthy of exploring as a potential drug target candidate. Appealingly, it was reported that AS-A was essential in Leishmania donovani, making it a promising drug target. In the work herein we demonstrate that Leishmania infantum AS-A, similarly to Trypanosoma spp. and L. donovani, is able to use both ammonia and glutamine as nitrogen donors. Moreover, we have successfully generated LiASA null mutants by targeted gene replacement in L. infantum, and these parasites do not display any significant growth or infectivity defect. Indeed, a severe impairment of in vitro growth was only observed when null mutants were cultured in asparagine limiting conditions. Altogether our results demonstrate that despite being important under asparagine limitation, LiAS-A is not essential for parasite survival, growth or infectivity in normal in vitro and in vivo conditions. Therefore we exclude AS-A as a suitable drug target against L. infantum parasites.

Leishmania infantum Asparagine Synthetase A Is Dispensable for Parasites Survival and Infectivity.

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Joana Faria

2016-01-01

Full Text Available A growing interest in asparagine (Asn metabolism has currently been observed in cancer and infection fields. Asparagine synthetase (AS is responsible for the conversion of aspartate into Asn in an ATP-dependent manner, using ammonia or glutamine as a nitrogen source. There are two structurally distinct AS: the strictly ammonia dependent, type A, and the type B, which preferably uses glutamine. Absent in humans and present in trypanosomatids, AS-A was worthy of exploring as a potential drug target candidate. Appealingly, it was reported that AS-A was essential in Leishmania donovani, making it a promising drug target. In the work herein we demonstrate that Leishmania infantum AS-A, similarly to Trypanosoma spp. and L. donovani, is able to use both ammonia and glutamine as nitrogen donors. Moreover, we have successfully generated LiASA null mutants by targeted gene replacement in L. infantum, and these parasites do not display any significant growth or infectivity defect. Indeed, a severe impairment of in vitro growth was only observed when null mutants were cultured in asparagine limiting conditions. Altogether our results demonstrate that despite being important under asparagine limitation, LiAS-A is not essential for parasite survival, growth or infectivity in normal in vitro and in vivo conditions. Therefore we exclude AS-A as a suitable drug target against L. infantum parasites.

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

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

2016-03-01

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

Quantification of anti-Leishmania antibodies in saliva of dogs.

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

2017-08-15

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

Potencial terapéutico del aceite esencial de Chenopodium ambrosioides y algunos de sus componentes frente a Leishmania

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Monzote Fidalgo, Lianet

2010-01-01

La leishmaniosis es una enfermedad causada por parásitos protozoos del género Leishmania, clasificada por la Organización Mundial de la Salud como una de las infecciones tropicales más importantes. Los fármacos disponibles son tóxicos, costosos y la resistencia parasitaria ha emergido. En las áreas endémicas la población depende fundamentalmente de la medicina natural para el tratamiento de la leishmaniosis. En este trabajo, se evaluó la actividad del aceite esencial extraído de Chenopodium a...

Manipulación genética y el estudio del parásito protozoario Leishmania.

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Tania M. Cortázar

2004-12-01

Full Text Available Durante los últimos 15 años se ha dado paso al entendimiento de muchos aspectos de la genómica funcional de Leishmania gracias a los avances en la metodología de transfección de ADN dentro de la célula de este protozoario, la eliminación y la complementación de genes por medio de recombinación homóloga y las estrategias para la selección de células transfectadas. Estos acercamientos tienen el potencial de brindar información sobre la expresión génica y la función de las proteínas en el contexto del parásito intacto. Dado que el genoma de Leishmania muestra una carencia acentuada de los factores conocidos de iniciación de la transcripción y que la expresión génica está regulada casi completamente a nivel postranscripcional (a través del empalme de los ARNm y los mecanismos que involucran el procesamiento diferencial de la región no traducida 3' del ARNm (3?UTR, la transfección génica representa una herramienta útil para la identificación y el análisis funcional de los genes de interés así como de los mecanismos que dirigen su regulación. El desarrollo de los sistemas de manipulación genética también ha abierto nuevos horizontes para la identificación de genes esenciales involucrados en la virulencia, la supervivencia intracelular y la resistencia a drogas de Leishmania, así como para la validación de proteínas específicas del parásito como nuevos blancos quimio e inmunoterapéuticos. En esta revisión presentamos los avances más recientes en el campo de la manipulación genética en Leishmania, los cuales permiten análisis estructurales, funcionales y de fenotipo, por medio de la eliminación y complementación génica a través de la transfección transitoria o permanente de genes en este parásito.

Cryopreservation of Leishmania Species in Manisa Province.

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

2017-09-01

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

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

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Ralph Lainson

1987-09-01

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

LEVANTAMENTO EPIDEMIOLÓGICO DE INFECÇÃO POR ACINETOBACTER SPP EM AMOSTRAS DE HEMOCULTURAS DE UM LABORATÓRIO DE SÃO JOSÉ DOS CAMPOS

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Vânia Waleska Sousa da Cunha

2015-01-01

Full Text Available A presença de infecções na corrente sanguínea representa uma grave complicação na situação de pacientes críticos, podendo aumentar os riscos de morbidade e mortalidade, sendo a hemocultura um importante recurso no diagnóstico do agente microbiano. Entre as bactérias causadoras de bacteriemia, encontramos, frequentemente, a Acinetobacter spp, sendo um patógeno de grande importância clínica devido ao aumento de sua frequência como causa de infecções hospitalares e, também, por, normalmente, apresentar multirresistência aos agentes antimicrobianos de prática clínica. O presente estudo teve como finalidade o levantamento epidemiológico de infecções em hemoculturas causadas pelo gênero Acinetobacter spp em pacientes internados, em hospitais de São José dos Campos-SP, demonstrando sua prevalência no munícipio. Os dados analisados foram fornecidos pelo sistema de um laboratório de análises microbiológicas e utilizados para o levantamento de infecções por Acinetobacter spp em hemoculturas, no período de agosto de 2012 a agosto de 2013. Foram avaliados 5.759 exames de hemocultura, com 1.019 resultados positivos, sendo que Acinetobacter baumannii foi identificada em 31 amostras, correspondendo ao sexto patógeno mais isolado (3,04% das hemoculturas positivas. A. baumannii se tornou um patógeno de grande preocupação hospitalar, devido à sua crescente colonização nas Unidades de Tratamento Intensivo e sua multirresistência aos antimicrobianos.

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

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Yeda L. Nogueira

2006-12-01

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

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

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Carla J.R.M. do Rosário

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

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

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

2017-11-01

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

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

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Elizaide L. A. Yoshida

1993-09-01

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

DNA fingerprinting by ERIC-PCR for comparing Listeria spp. strains isolated from different sources in San Luis: Argentina Caracterización molecular por ERIC-PCR de cepas de Listeria spp. aisladas de diversos orígenes en San Luis: Argentina

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A. Laciar

2006-04-01

Full Text Available In this study, a total of 24 Listeria spp. strains were analyzed. Twenty-two isolates were obtained in San Luis (Argentina from human, animal, and food samples. Two types of strains, Listeria monocytogenes CLIP 22762 and Listeria innocua CLIP 74915, were included as reference strains. All isolates were biochemically identified and characterized by serotyping, phage typing, and amplification of the flaA gene by polymerase chain reaction (PCR. Repetitive intergenic consensus (ERIC sequence-based PCR was used to generate DNA fingerprints. On the basis of ERIC-PCR fingerprints, Listeria spp. strains were divided into three major clusters matching origin of isolation. ERIC-PCR fingerprints of human and animal isolates were different from those of food isolates. In addition, groups I and II included ten L. monocytogenes strains, and only one Listeria seeligeri strain. Group III included nine L. innocua strains and four L. monocytogenes strains. Computer evaluation of ERIC-PCR fingerprints allowed discrimination between the tested serotypes 1/2b, 4b, 6a, and 6b within each major cluster. The index of discrimination calculated was 0.94. This study suggests that the ERIC-PCR technique provides an alternative method for the identification of Listeria species and the discrimination of strains within one species.En este estudio se analizaron 24 cepas de Listeria spp. De ellas, 22 fueron obtenidas en San Luis (Argentina, a partir de muestras humanas, de animales y alimentos. Se incluyeron 2 cepas de referencia Listeria monocytogenes CLIP 22762 y Listeria innocua CLIP 74915. Todos los aislamientos fueron identificados bioquímicamente y caracterizados por serotipificación, fagotipificación y detección del gen flaA por reacción en cadena de la polimerasa (PCR. Se generaron perfiles de bandas de ADN mediante la amplificación de secuencias repetitivas de consenso intergénico de enterobacterias (ERIC-PCR. De acuerdo a los resultados obtenidos por ERIC

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

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

2016-11-01

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

Purification of a Fe-SOD excreted by Leishmania braziliensis for specific antibodies detection in Mexican human sera: Cutting-edge the knowledge

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Silvia Stefania Longoni

2016-06-01

Full Text Available Clinical diagnosis of leishmaniasis is highly complex, presenting a wide range of clinical manifestations, sometimes non-specific, and thus the epidemiological study and diagnostic need specific molecular markers for each Leishmania species. Leishmania spp. posses different Fe-SOD isoforms, one of which is excreted into the external milieu and, presenting immunogenic characteristics, is a very reliable molecular marker. Superoxide dismutases (SODs are antioxidant metal-enzymes responsible for the dismutation of superoxide ion into hydrogen peroxide and molecular oxygen, and it is considered an important virulence factor. In this manuscript we have purified the iron(Fe-SOD excreted by Leishmania braziliensis using ion-exchange and molecular-sieve chromatography and we have studied it as an antigen in serodiagnostic analyses in ELISA and Western blot techniques, testing 213 human sera from Mexico. Indeed, L. braziliensis Fe-SODe has been purified 123.26 times with a specific activity of about 893.66 U/mg of protein. Applying the purified enzymes in serological tests we found 17.84% sera positive. We have demonstrated that the purified enzyme is more sensitive than the non-purified ones and we also demonstrated, for the first time, the presence of antibodies against L. braziliensis, not the main species in the country, in human population from Hidalgo and Nuevo Leon States.

Leishmania Hijacks Myeloid Cells for Immune Escape

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María Martínez-López

2018-05-01

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

Arginase activity of Leishmania isolated from patients with cutaneous leishmaniasis.

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

2017-09-01

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

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

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2013-02-07

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

Estudio ultraestructural de la fagocitosis de promastigotes y amastigotes de Leishmania mexicana por la línea de células dendríticas FSDC

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Ladys Sarmiento

2006-10-01

Full Text Available Introducción. Las células dendríticas están presentes en la mayoría de los tejidos, ellas capturany presentan antígenos para activar a los linfocitos T. Objetivo. Se describe ultraestructuralmente la fagocitosis de Leishmania mexicana por lalínea de células dendríticas FSDC, una línea de células de Langerhans obtenida de la epidermisfetal de ratón, e inmortalizada por la transducción retroviral del oncogen v-myc. Materiales y métodos. Se obtuvieron amastigotes de la lesión de ratones Balb/c y promastigotesa partir del cultivo (24°C de la lesión. Las FSDC se cultivaron con los parásitos en unaproporción de 5 parásitos por célula, en medio IMDM, durante 24 horas. Los cultivos infectadosy los controles se procesaron para microscopía electrónica de transmisión. Se hicieron cortessemifinos contrastados con azul de toluidina para evaluar porcentaje de fagocitosis y finos,contrastados con acetato de uranilo y citrato de plomo. Resultados. El 13,42% de las FSDC fagocitaron promastigotes; de ellas el 8% contenían unparásito y el restante 5,2% fagocitó dos o más. El 20% de las FSDC fagocitaron amastigotes;10% contenían un parásito y 10% dos o más. Ultraestructuralmente se observaron promastigotesen contacto con las células por el flagelo o por el polo posterior. Los fagosomas que conteníanpromastigotes eran organelos estrechos con uno ó dos parásitos. Los que conteníanamastigotes eran de gran tamaño (8 μm con uno o varios parásitos, libres o adosados a lamembrana del fagosoma por su polo posterior. Conclusión. La infección de las FSDC se caracterizó por una baja tasa de células infectadasal ser expuestas a promastigotes o amastigotes. La vacuola parasitofora presentó característicassimilares a las de los macrófagos. En su mayoría las FSDC presentaban 1 a 3 parásitos porcélula. Las observaciones plantean la necesidad de estudiar la relación entre capacidad defagocitosis y función.

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

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Louise Basmaciyan

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

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

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Basmaciyan, Louise; Azas, Nadine; Casanova, Magali

2017-01-01

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

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

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Marcelo Rosandiski LYRA

2015-10-01

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

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.

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

2010-01-01

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

Ocorrência de anticorpos e fatores de risco associados à infecção por Leptospira spp. em Cebus spp. mantidos em cativeiro no Nordeste do Brasil

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Débora R.A. Ferreira

2011-11-01

Full Text Available Estudou-se a ocorrência de anticorpos anti-Leptospira e os fatores de risco associados à infecção em primatas do gênero Cebus mantidos em cativeiro no Nordeste do Brasil. Foram analisadas 139 amostras de soro sanguíneo de diferentes espécies de primatas de ambos os sexos e idades variadas. Para a pesquisa de anticorpos empregou-se a técnica de Soroaglutinação Microscópica (SAM e para estudo dos fatores de risco utilizou-se análise multivariada. Foram observados anticorpos anti-Leptospira, sorovar Patoc em 6,5% dos primatas (09/139. O fator de risco identificado nesse estudo foi a não higienização diária de bebedouros (Odds ratio=12,095; IC 95% = 1,73-84,52; p=0,012,. Conclui-se que a população de Cebus mantidos em cativeiros no Nordeste do Brasil está exposta à infecção por anticorpos anti-Leptospira e que medidas corretivas de manejo dos animais, especificamente aquelas relacionadas à higienização diária de bebedouros devem ser implementadas para reduzir o risco de infecção por sorovares de Leptospira spp.

Perfil fitoquímico, actividad anti-Leishmania, hemolítica y toxicológica de Cordia dentata Poir. y Heliotropium indicum L.

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Espitia-Baena, Jorge Eliecer; Robledo-Restrepo, Sara María; Soraya Cuadrado-Cano, Bernarda; Duran-Sandoval, Harriette del Rosario; Gómez-Estrada, Harold Alberto

2014-01-01

Introducción: la leishmaniasis constituye un grave problema de salud pública a nivel mundial. En Colombia, la forma clínica cutánea tiene la mayor incidencia y es causada principalmente por especies de Leishmania (Viannia) panamensis. Dado que los tratamientos disponibles para esta enfermedad resultan ineficaces, es necesaria la búsqueda de nuevos agentes terapéuticos en especies vegetales utilizadas por la medicina popular. Objetivo: evaluar el perfil fitoquímico, la actividad hemolítica, ci...

AVALIAÇÕES CITOLÓGICAS EM OTITES CANINAS POR MALASSEZIA SPP.: ESTUDO RETROSPECTIVO

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Alessandra Melchert

2011-12-01

Full Text Available Otitis externa is a condition frequently observed in dogs at the small animal clinics. Malassezia spp. is the most frequently isolated microorganism in the ears of dogs, which is one of the major etiologic agents of ear infections. Identification of this agent may be based on fungal culture or cytology, and the first method is longer and more expensive. The aim of this study was to conduct a retrospective study of the incidence of Malassezia spp. in cases of canine otitis by cytology, in a period of five years. Ear cytology samples from 249 dogs with suspected otitis were evaluated, and were observed positive samples for Malassezia spp. in 44 cases (17.67%, among these 35 dogs (79.5% with positive cytology in both ears, and 9 dogs (20.5% were positive for Malassezia in only one ear. In conclusion, dogs with suspected otitis present high incidence of positive Malassezia spp. cytology counts. Cytology revealed to be a useful tool for diagnosis of canine ear infections involving this pathogen, representing diagnostic alternative in cases where the culture is not feasible. However, one must consider that there is no national standard cytological counting yeast cells/field set for cases of canine otitis, which may represent possible misdiagnosis.

Prevalence of Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in apparently healthy and CVBD-suspect dogs in Portugal - a national serological study

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Cardoso Luís

2012-03-01

Full Text Available Abstract Background Canine vector-borne diseases (CVBDs are caused by a wide range of pathogens transmitted to dogs by arthropods including ticks and insects. Many CVBD-agents are of zoonotic concern, with dogs potentially serving as reservoirs and sentinels for human infections. The present study aimed at assessing the seroprevalence of infection with or exposure to Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in dogs in Portugal. Methods Based on 120 veterinary medical centres from all the regions of mainland and insular Portugal, 557 apparently healthy and 628 CVBD-suspect dogs were sampled. Serum, plasma or whole blood was tested for qualitative detection of D. immitis antigen and antibodies to E. canis, B. burgdorferi s. l., Anaplasma spp. and L. infantum with two commercial in-clinic enzyme-linked immunosorbent assay kits. Odds ratios (OR were calculated by logistic regression analysis to identify independent risk factors of exposure to the vector-borne agents. Results Total positivity levels to D. immitis, E. canis, B. burgdorferi, Anaplasma spp., L. infantum, one or more agents and mixed agents were 3.6%, 4.1%, 0.2%, 4.5%, 4.3%, 14.0% and 2.0% in the healthy group, and 8.9%, 16.4%, 0.5%, 9.2%, 25.2%, 46.3% and 11.6% in the clinically suspect group, respectively. Non-use of ectoparasiticides was a risk factor for positivity to one or more agents both in the apparently healthy (OR = 2.1 and CVBD-suspect (OR = 1.5 dogs. Seropositivity to L. infantum (OR = 7.6, E. canis (OR = 4.1 and D. immitis (OR = 2.4 were identified as risk factors for the presence of clinical signs compatible with CVBDs. Positivity to mixed agents was not found to be a risk factor for disease. Conclusions Dogs in Portugal are at risk of becoming infected with vector-borne pathogens, some of which are of zoonotic concern. CVBDs should be considered by practitioners and prophylactic measures must be put in

Efecto de la fagocitosis, la infección po Leishmania amazonenesis y Leshmania braziliensis sobre la distribción de filamentos de actina y microtúbulos en macrófagos murinos

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Chacón Rojas, Marcos Nicolás

2011-01-01

Por inmunofluorescencia se estudió la distribución del citoesqueleto en macrófagos activados, con fagosomas de diferentes tamaños e infectados con Leishmania. También se evaluaron los niveles de actina y tubulina en los mismos grupos. Se encontró que fagosomas grandes alteran la distribución del citoesqueleto sin afectar niveles de actina y tubulina. / Abstract. Cytoskeleton distribution was studied in macrophages activated, with phagosomes of different size and infected with Leishmania pa...

Leishmania major methionine sulfoxide reductase A is required for resistance to oxidative stress and efficient replication in macrophages.

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Fiona M Sansom

Full Text Available Leishmania are protozoan parasites that proliferate within the phagolysome of mammalian macrophages. While a number of anti-oxidant systems in these parasites have been shown to protect against endogenous as well as host-generated reactive oxygen species, the potential role of enzymes involved in the repair of oxidatively damaged proteins remains uncharacterized. The Leishmania spp genomes encode a single putative methionine sulfoxide reductase (MsrA that could have a role in reducing oxidized free and proteinogenic methionine residues. A GFP-fusion of L. major MsrA was shown to have a cytoplasmic localization by immunofluorescence microscopy and subcellular fractionation. An L. major msrA null mutant, generated by targeted replacement of both chromosomal allelles, was viable in rich medium but was unable to reduce exogenous methionine sulfoxide when cultivated in the presence of this amino acid, indicating that msrA encodes a functional MsrA. The ΔmsrA mutant exhibited increased sensitivity to H(2O(2 compared to wild type parasites and was unable to proliferate normally in macrophages. Wild type sensitivity to H(2O(2 and infectivity in macrophages was restored by complementation of the mutant with a plasmid encoding MsrA. Unexpectedly, the ΔmsrA mutant was able to induce normal lesions in susceptible BALB/c indicating that this protein is not essential for pathogenesis in vivo. Our results suggest that Leishmania MsrA contributes to the anti-oxidative defences of these parasites, but that complementary oxidative defence mechansims are up-regulated in lesion amastigotes.

Erythema exsudativum multiforme after a Leishmania skin test

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

2014-01-01

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

Amiloidosis en Didelphis marsupialis infectado experimentalmente con Leishmania chagasi.

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Diana Milena Roa

2002-09-01

Full Text Available Un Didelphis marsupialis macho capturado en Teruel, Huila, se inoculó intraperitonealmente con 1x106 promastigotes de Leishmania chagasi (MHOM/CO/84/CL044B. El animal desarrolló leishmaniosis visceral con abundantes amastigotes fagocitados en las células de Kupffer y en los macrófagos esplénicos; murió 5 semanas después de la inoculación. La autopsia reveló amplios depósitos de amiloide en el hígado y en el bazo, demostrados por sus características tintoriales y ultraestructurales. La consideramos como una amiloidosis secundaria a la infección experimental, que ocurrió en el transcurso de 5 semanas luego de inoculado el animal.

Compostos antimicrobianos produzidos por Streptomyces Spp.

OpenAIRE

Silva, Ingrid Reis da

2012-01-01

O aumento crescente de bact?rias resistentes a antibi?ticos incentiva ? pesquisa por novas subst?ncias antibacterianas. Diante disso, a sele??o de microrganismos com potencial para a produ??o de novos compostos antimicrobianos tem sido amplamente estudada. Dentre estes microrganismos uma especial aten??o ? dada aos actinomicetos que apresentam capacidade de produzir uma variedade de compostos bioativos como antibi?ticos, antif?ngicos, antitumorais entre outros compostos que pod...

Lutzomyia gasparviannai Martins, Godoy & Silva, 1962, probable vector of Leishmania mexicana ssp. in Viana municipality, Espírito Santo State, Brazil

OpenAIRE

Falqueto,Aloísio; Grimaldi Júnior,Gabriel; Sessa,Paulo Augusto; Varejão,José Benedito Malta; Deane,Leonidas M.

1985-01-01

Dos flebótomos atraídos pelo Proechimys iheringi numa área onde esse roedor foi achado naturalmente infectado por Leishmania mexicana ssp., 98,1% foram Lutzomyia gasparviannai, o que sugere que essa espécie não antropofílica seja o transmissor entre os roedores mas não habitualmente ao homem.

Lutzomyia gasparviannai Martins, Godoy & Silva, 1962, probable vector of Leishmania mexicana ssp. in Viana municipality, Espírito Santo State, Brazil

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Aloísio Falqueto

1985-12-01

Full Text Available Dos flebótomos atraídos pelo Proechimys iheringi numa área onde esse roedor foi achado naturalmente infectado por Leishmania mexicana ssp., 98,1% foram Lutzomyia gasparviannai, o que sugere que essa espécie não antropofílica seja o transmissor entre os roedores mas não habitualmente ao homem.

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

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

2018-01-01

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

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

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Helena Messlinger

2018-01-01

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

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

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2013-01-01

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

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

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Philip Davis Marsden

1994-06-01

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

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

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Francielle Pelegrin Garcia

2013-01-01

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

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

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Kelly Ben L

2010-02-01

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

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

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Élide Aparecida Oliveira

2011-01-01

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.

Risk factors for Leishmania chagasi infection in an endemic area in Raposa, State of Maranhão, Brazil Fatores associados à infecção por Leishmania chagasi em uma área endêmica em Raposa, Estado do Maranhão, Brasil

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Charlene Barreto Ponte

2011-12-01

Full Text Available INTRODUCTION: Infection with Leishmania chagasi is the most common clinical presentation for visceral leishmaniaisis in endemic areas. The municipality of Raposa is an endemic area in State of Maranhão, Brazil, and have had registration cases of visceral leishmaniasis disease. For this reason, a cross- sectional study was conducted to evaluate the risk factors for infection with L. chagasi detected by Montenegro skin test. METHODS: The sample comprised 96% of the inhabitants of the villages of Maresia, Pantoja, and Marisol located in the municipality of Raposa, corresponding to 1,359 subjects. Data were collected using a questionnaire. Univariate and multivariate logistic regression models were applied to evaluate the association between the variables studied and infection of L. chagasi. RESULTS: The variables associated with infection upon nonadjusted analysis were a straw roof, mud walls, floors of beaten earth, presence of sand flies inside or outside of the dwelling, and bathing outdoors. Adjusted analysis showed that the presence of sand flies inside/outside the dwelling was a risk factor, and age younger than 10 years was a protective factor against asymptomatic infection. CONCLUSIONS: The results highlight the extent to which precarious living conditions of the population strengthen the epidemiological chain of visceral leishmaniasis.INTRODUÇÃO: A infecção por Leishmania chagasi é a apresentação clínica mais comum de laishmaniose visceral em áreas endêmicas. O município de Raposa é área endêmica no Estado do Maranhão, tendo registrado casos da doença. Por isso, realizou-se um estudo transversal, com o objetivo de estudar os fatores de risco para infecção por L. chagasi detectada pelo teste intradérmico de Montenegro. MÉTODOS: O estudo envolveu 96% dos moradores das localidades de Maresia, Pantoja e Marisol do município da Raposa, totalizando 1.359 indivíduos. O levantamento dos dados foi realizado utilizando um

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

Indian Academy of Sciences (India)

NII

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

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

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

2010-05-01

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

Onicomicose por Scytalidium spp.: estudo clínico-epidemiológico em um hospital universitário do Rio de Janeiro, Brasil Onycomychosis due to Scytalidium spp.: a clinical and epidemiologic study at a University Hospital in Rio de Janeiro, Brazil

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Ígor Brum Cursi

2011-08-01

Full Text Available FUNDAMENTOS: O Scytalidium spp. é fungo filamentoso, saprobio do solo e plantas, considerado, atualmente, patógeno primário das unhas. A prevalência das infecções ungueais causadas por este fungo vem aumentando nas últimas décadas, embora ainda sejam poucos os trabalhos publicados sobre sua epidemiologia. OBJETIVO: Estudo clínico-epidemiológico dos pacientes portadores de onicomicose por Scytalidium spp. em um hospital universitário do Rio de Janeiro. MÉTODOS: Foram avaliados os dados clínico-epidemiológicos de 30 pacientes com onicomicose por Scytalidium spp. por meio do estudo observacional de 1.295 pacientes que se submeteram a exame micológico ungueal no período de 16 meses. RESULTADOS: A maioria dos pacientes era do sexo feminino (66,6%, a média de idade foi de 56,7 anos e 63,3% eram não-brancos. O nível de escolaridade em 53,3% dos pacientes era o ensino fundamental e a renda familiar predominante foi de 3 a 5 salários mínimos em 36,6% dos entrevistados. Em 90% dos casos, as unhas dos pododáctilos foram acometidas, sendo a alteração clínica mais comum a onicólise (18 pacientes e em 66,6% dos casos observou-se melanoníquia. O tempo de evolução da doença foi maior do que cinco anos em 43,3% dos casos. Dezenove pacientes (63,3% já haviam realizado tratamento medicamentoso para o quadro atual. CONCLUSÕES: Os dados mostram que a infecção ungueal pelo Scytalidium spp. é crônica, mais comum no sexo feminino (2:1 e atinge indivíduos adultos. Clinicamente, é semelhante às dermatofitoses. A prevalência na amostra estudada foi de 4,86% e correspondeu a 26,92% dos exames positivosBACKGROUND: Scytalidium sp. is a filamentous (thread-like, saprobic fungus which affects soil and plants. It is currently considered a primary pathogen of the nail. The prevalence of nail infections caused by this fungus has been increasing in recent decades, although few published studies have been done on its epidemiology. OBJECTIVE

Little evidence of seasonal variation of natural infection by Leishmania infantum in dogs in Spain.

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Fernández-Bellon, H; Solano-Gallego, L; Rodríguez-Cortés, A; Ferrer, L; Gallego, M; Alberola, J; Ramis, A

2008-08-01

Leishmania infantum, the etiological agent of canine leishmaniosis in the Mediterranean region, is vectored by Phlebotomus spp sandflies, which are active during the warmer months of the year. In order to determine whether seasonality in transmission induces seasonal changes in the prevalence of infection by L. infantum and of parasite-specific immune response, two groups of dogs, one in February (n=37) and another in October (n=42), were studied. Clinical signs compatible with leishmaniosis, as well as presence of microscopic skin lesions in the muzzle were recorded for all dogs. Assays were also performed for detection of L. infantum parasites in muzzle skin samples (PCR, immunohistochemistry and culture), specific serum antibodies (ELISA), and specific lymphocyte proliferation and interferon-gamma production. Although prevalence of non-specific clinical signs increased significantly after the sandfly season, this was not the case for Leishmania-specific markers: positivity by PCR (24% vs. 21%) or immunohistochemistry (3% vs. 2%) of muzzle skin samples, as well as lymphocyte proliferation (59% vs. 50%) or interferon-gamma production (21% vs. 27%) were similar in February and in October. Only prevalence of positive specific antibody titers increased noticeably in October (8% vs. 20%), although this was not statistically significant. Overall, the sandfly season did not have a marked impact on the prevalence L. infantum infection or parasite-specific immune responses analyzed in this study.

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

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

2017-05-16

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

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

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Lianet Monzote

2007-08-01

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

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

Science.gov (United States)

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

2016-03-01

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

From genomes to vaccines: Leishmania as a model.

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

2002-01-01

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

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

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

2017-11-01

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

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

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

2013-09-23

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

Cryptosporidium spp. infection in mares and foals of the northwest region of São Paulo State, Brazil Infecção por Cryptosporidium spp. em éguas e potros da região noroeste do estado de São Paulo, Brasil

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Sandra Valéria Inácio

2012-12-01

Full Text Available The present study aimed to analyze the occurrence of infection by Cryptosporidium spp. in mares and their respective foals. This study was carried out in 11 farms located in the municipalities of Araçatuba, Birigui, Guararapes and Santo Antônio do Aracangua, in the northwest region of the State of Sao Paulo, from November 2010 to March 2011. A total of 98 mares and 98 foals of several breeds were analyzed; among foals, 59 were males and 39 females, aged from three to 330 days. Feces were collected directly from the rectal ampulla, purified and processed according to modified Kinyoun stain. Occurrence of Cryptosporidium spp. was 21.4% (21/98 for foals and 18.4% (18/98 for mares. Occurrence of Cryptosporidium spp. had significant association with breeds and age of animals. Results obtained led to the conclusion that foals older than two months and Mangalarga animals are less susceptible to the occurrence of Cryptosporidium spp.O presente estudo teve como objetivo analisar a ocorrência da infecção por Cryptosporidium spp. em éguas e seus respectivos potros. Este estudo foi realizado em 11 fazendas localizadas nos municípios de Araçatuba, Birigui, Guararapes e Santo Antônio do Aracangua, na região Noroeste do Estado de São Paulo, de novembro de 2010 a março de 2011. Um total de 98 éguas e 98 potros de diversas raças foram analisados, sendo que, entre os filhotes, 59 eram machos e 39 fêmeas, cujas idades variavam de três até 330 dias. Fezes foram colhidas diretamente da ampola retal, purificadas e processadas pela técnica de Kinyoun modificada. A ocorrência de Cryptosporidium spp. observada foi de 21,4% (21/98 para potros e 18,4% (18/98 para éguas. A ocorrência de Cryptosporidium spp. teve uma associação significativa com a raça e a idade dos animais. A partir dos resultados obtidos, conclui-se neste estudo que potros com idade superior a dois meses e animais da raça Mangalarga foram menos susceptíveis à ocorrência de

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

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Kárita Cláudia Freitas-Lidani

2014-07-01

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

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

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

2015-01-01

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

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

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2013-01-01

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

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

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

2015-01-01

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

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

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Jarina Pena DaMata

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

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

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

2010-01-01

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

Genetic Diversity in Natural Populations of New World Leishmania

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Cupolillo Elisa

1998-01-01

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

Screening For Inhibitors Of Essential Leishmania Glucose Transporters

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2011-07-01

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

Molecular crosstalks in Leishmania-sandfly-host relationships

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Volf P.

2008-09-01

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

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

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Regina Coeli Cunha Dórea

2003-11-01

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.

Single and concomitant experimental infectionsby Endotrypanum spp. and Leishmania (Viannia guyanensis (Kinetoplastida: Trypanosomatidae in the Neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae

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André F Barbosa

2006-12-01

Full Text Available Lutzomyia longipalpis females received single and mixed infections with Endotrypanum and Leishmania. Two biological parameters were analyzed: the percentage of infected females and the distribution of flagellates in the gut of the females. The principal comparisons were performed between (1 two strains of Endotrypanum, (2 cloned versus primary sample of one strain of Endotrypanum, (3 Endotrypanum versus Leishmania guyanensis, and (4 the pattern of flagellates behaviour by optical microscopy in females with single or mixed infection versus the identification of parasites isolated from digestive tracts by isoenzyme electrophoresis. Flagellates of Endotrypanum showed distinct patterns of infection suggesting that there is variation between and within strains. The distribution of Endotrypanum and L. guyanensis differed significantly in relation to the colonization of the stomodeal valve. In co-infection with L. guyanensis, a large number of flagellates were seen to be plentifully infecting the stomodeal valve in significantly more specimens than in females infected by Endotrypanum only. However, the electrophoretic profiles of isoenzymes of parasites recovered from all co-infected specimens corresponded to Endotrypanum. This suggests that the mere correlation sand fly infection-biochemical analysis of isolates may induce parasitological incorrect consideration.

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

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

2017-10-01

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

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

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Ryuichi Miura

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

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

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Letícia da Cruz Sanches

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

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

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Elisa San Martin Mouriz Savani

2011-08-01

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

RIPK1 and PGAM5 Control Leishmania Replication through Distinct Mechanisms.

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

2016-06-15

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

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

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Mohammad Akhoundi

2016-03-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2016-03-01

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

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

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Erico Vinícius de Souza Carmo

2010-11-01

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

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

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

2011-02-01

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

Seroprevalence rates of antibodies against Leishmania infantum and other protozoan and rickettsial parasites in dogs Soroprevalência de anticorpos contra Leishmania infantum e outras espécies de protozoários e rickettsia em cães

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Silvana de Cássia Paulan

2013-03-01

Full Text Available Canine visceral leishmaniasis (CVL is caused by the protozoan Leishmania infantum, which infects dogs and humans in many regions of Brazil. The present study involved an indirect fluorescent antibody test (IFAT to analyze L. infantum, Ehrlichia spp., Babesia canis, Toxoplasma gondii and Neospora caninum infection rates in serum samples from 93 dogs in a rural settlement in Ilha Solteira, SP, Brazil. The seroprevalence rates of anti-L. infantum, anti-Ehrlichia, anti-B. canis, anti-T. gondii and anti-N. caninum antibodies were 37.6%, 75.3%, 72%, 47.3% and 6.4%, respectively. In addition to IFAT, direct microscopic examination of popliteal lymph node aspirates revealed 26.9% of CVL positive dogs. Serological tests revealed that 17.2% of the dogs were seropositive for a single parasite, 29% for two parasites, 33% for three, 16.1% for four, and 1.1% for five parasites, while 3.2% were seronegative for five parasites. The presence of antibodies against these parasites in serum samples from dogs confirmed their exposure to these parasites in this rural area. Because of the potential zoonotic risk of these diseases, mainly leishmaniasis, ehrlichiosis and toxoplasmosis, special attention should focus on programs for the improvement of diagnostic assays and control measures against these parasites.Leishmaniose Visceral Canina (LVC é causada pelo protozoário Leishmania infantum, podendo infectar cães e humanos em várias regiões do Brasil. O presente estudo teve por objetivo realizar a reação de imunofluorescência indireta (RIFI para analisar os índices de infecção parasitária para L. infantum, Ehrlichia spp., Babesia canis, Toxoplasma gondii e Neospora caninum, em 93 amostras de soro de cães de um assentamento rural no município de Ilha Solteira, SP, Brasil. A taxa de soroprevalência de cães com anticorpos anti-L. infantum, anti-Ehrlichia, anti-B. canis, anti-T. gondii e anti-N. caninum foi de 37,6%, 75,3%, 72%, 47,3% e 6

Susceptibilidad de genotipos de Solanum spp. al nematodo causante del nudo radical Meloidogyne spp. (chitwood) Susceptibility of genotypes of Solanum spp. to the nematode causative of the root knot Meloidogyne spp. (chitwood)

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Cristian Gelpud Chaves

2011-01-01

Full Text Available El cultivo del lulo (Solanum quitoense L.) presenta una disminución en su productividad, debido al ataque de patógenos como el nematodo del nudo radical Meloidogyne spp., en el Departamento de Nariño (Colombia), se han reportado incidencias cercanas al 79%, y pérdidas del 50%. En la presente investigación, se colectaron 45 genotipos de (Solanum quitoense L.) en los Departamentos de Nariño y Putumayo y 4 genotipos silvestres (S. mammosum, S. hirtum, S. marginatum y S. umbellatum) buscando fuentes de resistencia al nematodo. Se inocularon 9 plantas de cada genotipo de dos meses de edad con 10000 huevos de Meloidogyne spp., dejando tres testigos por cada material. Las variables evaluadas fueron: altura de planta, severidad, incidencia, peso fresco (tallo y raíz) y especies prevalentes de Meloidogyne spp. Se hizo una clasificación de genotipos mediante escala de resistencia y regresión entre la severidad y las demás variables para establecer el efecto de Meloidogyne spp. sobre los genotipos de planta. Los resultados mostraron 100% de incidencia del nematodo en todos los genotipos, 2.04% genotipos resistentes, 34.7% moderadamente resistentes, 42.8% moderadamente susceptibles, 18.3% susceptibles, y 2.04% altamente susceptibles. El genotipo SQbr05 resistente, no se vio afectado por la severidad, al contrario SQbc04 genotipo susceptible, mostró reducciones significativas en peso fresco de tallo y raíz, (R² = 0.71 y 0.98), el genotipo silvestre (S. mammosum) es altamente susceptible, Meloidogyne incognita presentó 55.31% de presencia. El genotipo SQbr05 es promisorio para ser evaluado en campo.The green orange (Solanum quitoense L.) crop has decreased in its productivity due to the pathogens attack such as the root knot nematode Meloidogyne spp. In the Nariño Department of Colombia, pest incidences near to 79% and losses of 50% have been reported. In this study, 45 genotypes of Solanum quitoense were collected in Nariño and Putumayo

Susceptibilidad de genotipos de Solanum spp. al nematodo causante del nudo radical Meloidogyne spp. (chitwood

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Gelpud Chaves Cristian

2011-03-01

Full Text Available

El cultivo del lulo (Solanum quitoense L. presenta una disminución en su productividad, debido al ataque de patógenos como el nematodo del nudo radical Meloidogyne  spp., en el Departamento  de Nariño (Colombia, se han reportado incidencias cercanas al 79%, y pérdidas del 50%.   En la presente investigación, se colectaron 45 genotipos de (Solanum quitoense  L. en los Departamentos  de Nariño  y Putumayo  y 4 genotipos  silvestres  (S. mammosum, S. hirtum,       S. marginatum  y S. umbellatum buscando fuentes de resistencia al nematodo. Se inocularon 9 plantas de cada genotipo de dos meses de edad con 10000 huevos de Meloidogyne spp., dejando tres testigos por cada material. Las variables evaluadas fueron: altura de planta, severidad, incidencia, peso fresco (tallo y raíz y especies prevalentes de Meloidogyne spp. Se hizo una clasificación de genotipos mediante escala de resistencia y regresión entre la severidad y las demás variables para establecer el efecto de Meloidogyne spp. sobre los genotipos de planta. Los resultados mostraron 100% de incidencia del nematodo en  todos  los  genotipos,  2.04%  genotipos  resistentes,  34.7%  moderadamente  resistentes, 42.8% moderadamente susceptibles, 18.3% susceptibles, y 2.04% altamente susceptibles. El genotipo SQbr05 resistente, no se vio afectado por la severidad, al contrario SQbc04 genotipo susceptible, mostró reducciones significativas en peso fresco de tallo y raIz, (R2 = 0.71 y 0.98,el genotipo silvestre (S. mammosum es altamente susceptible, Meloidogyne incognita presentó 55.31% de presencia. El genotipo SQbr05 es promisorio para ser evaluado en campo.

Innate Immunity to Leishmania Infection: Within Phagocytes

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Marcela Freitas Lopes

2014-01-01

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

Endocarditis bacteriana por Kocuria kristinae en paciente inmunocompetente. Reporte de un caso

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Alirio R. Bastidas, MD; Carlos A. Vélez, MD; Carol V. Gutiérrez M.; Nancy J. Bahamón

2013-01-01

Las infecciones por microorganismos del género Kocuria spp. han sido descritas con mayor frecuencia en pacientes con enfermedades crónicas y estados de inmunosupresión. Comúnmente, no se ha reportado su aislamiento como causa de endocarditis en pacientes jóvenes e inmunocompetentes. Se deben diferenciar de las infecciones producidas por Staphylococcus spp. ya que su evolución clínica puede ser similar y sólo el aislamiento y tipifi cación en cultivos permite hacer el diagnóstico etiológico de...

Serum Removal from Culture Induces Growth Arrest, Ploidy Alteration, Decrease in Infectivity and Differential Expression of Crucial Genes in Leishmania infantum Promastigotes.

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Pedro J Alcolea

Full Text Available Leishmania infantum is one of the species responsible for visceral leishmaniasis. This species is distributed basically in the Mediterranean basin. A recent outbreak in humans has been reported in Spain. Axenic cultures are performed for most procedures with Leishmania spp. promastigotes. This model is stable and reproducible and mimics the conditions of the gut of the sand fly host, which is the natural environment of promastigote development. Culture media are undefined because they contain mammalian serum, which is a rich source of complex lipids and proteins. Serum deprivation slows down the growth kinetics and therefore, yield in biomass. In fact, we have confirmed that the growth rate decreases, as well as infectivity. Ploidy is also affected. Regarding the transcriptome, a high-throughput approach has revealed a low differential expression rate but important differentially regulated genes. The most remarkable profiles are: up-regulation of the GINS Psf3, the fatty acyl-CoA synthase (FAS1, the glyoxylase I (GLO1, the hydrophilic surface protein B (HASPB, the methylmalonyl-CoA epimerase (MMCE and an amastin gene; and down-regulation of the gPEPCK and the arginase. Implications for metabolic adaptations, differentiation and infectivity are discussed herein.

Serum Removal from Culture Induces Growth Arrest, Ploidy Alteration, Decrease in Infectivity and Differential Expression of Crucial Genes in Leishmania infantum Promastigotes.

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Alcolea, Pedro J; Alonso, Ana; Moreno-Izquierdo, Miguel A; Degayón, María A; Moreno, Inmaculada; Larraga, Vicente

2016-01-01

Leishmania infantum is one of the species responsible for visceral leishmaniasis. This species is distributed basically in the Mediterranean basin. A recent outbreak in humans has been reported in Spain. Axenic cultures are performed for most procedures with Leishmania spp. promastigotes. This model is stable and reproducible and mimics the conditions of the gut of the sand fly host, which is the natural environment of promastigote development. Culture media are undefined because they contain mammalian serum, which is a rich source of complex lipids and proteins. Serum deprivation slows down the growth kinetics and therefore, yield in biomass. In fact, we have confirmed that the growth rate decreases, as well as infectivity. Ploidy is also affected. Regarding the transcriptome, a high-throughput approach has revealed a low differential expression rate but important differentially regulated genes. The most remarkable profiles are: up-regulation of the GINS Psf3, the fatty acyl-CoA synthase (FAS1), the glyoxylase I (GLO1), the hydrophilic surface protein B (HASPB), the methylmalonyl-CoA epimerase (MMCE) and an amastin gene; and down-regulation of the gPEPCK and the arginase. Implications for metabolic adaptations, differentiation and infectivity are discussed herein.

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

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Rezvan, H; Rees, R; Ali, SA

2011-01-01

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

Leishmania serology in the diagnosis of cutaneous leishmaniasis

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

2013-01-01

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

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

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Schwenkenbecher Jan

2008-06-01

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

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

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

2015-10-19

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

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

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

2017-07-01

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

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

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

2017-02-01

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

Dihydrotestosterone enhances growth and infectivity of Leishmania Mexicana.

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

2018-03-01

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

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

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Rita C Bittar

2007-08-01

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

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

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

2016-06-01

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

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

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

2015-01-01

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

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

Science.gov (United States)

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

2015-12-11

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

Preparation of live attenuated leishmania parasites by using laser technology

Science.gov (United States)

Hussain, Nabiha; Alkhouri, Hassan; Haddad, Shaden

2018-05-01

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

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

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Ana V. Ibarra-Meneses

2017-09-01

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

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

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Ameer Khusro

2017-07-01

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

ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple Glomerella leaf spot Filogenia por ITS-rDNA de Colletotrichum spp., agente causal da mancha foliar da Gala em macieira

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Diorvania Ribeiro Giaretta

2010-04-01

Full Text Available Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered to isolates of pineapple guava and to the citrus isolates used as control.A produção de maçã vem sendo comprometida pela ocorrência de muitas doenças, entre as quais se destaca a Mancha Foliar de Glomerella (MFG, causada por Colletotrichum spp. O primeiro relato dessa doença em maçã foi registrado em plantas próximas a pomares de citrus no Estado de São Paulo, Brasil. A origem da MFG ainda não está bem clara, e estudos baseados na filogenia permitirão relacionar o organismo evolutivamente, possibilitando caracterizar possíveis mecanismos divergentes de evolução. A amplificação da região 5.8S-ITS (espaçador interno transcrito do rDNA de 51 isolados de Colletotrichum patogênicos em de maçã, goiabeira serrana e citrus produziu um fragmento de aproximadamente 600 pares de bases (pb para todos os isolados analisados

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

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Hamarsheh Omar

2012-08-01

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

LR1: a candidate RNA virus of Leishmania.

OpenAIRE

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

1988-01-01

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

El análisis molecular y el inmunogénico sugieren la ausencia de las proteínas hidrofílicas de superficie en Leishmania (Viannia panamensis

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Marcel Marín

2008-09-01

Full Text Available Introducción. Los dos subgéneros en los cuales se divide el género Leishmania: Viannia y Leishmania, presentan diferencias significativas en las manifestaciones clínicas que causan, en su comportamiento de crecimiento en cultivos in vitro, en sus características genéticas y en la expresión de varias proteínas, entre ellas las de la familia hidrofílica de superficie superficie. Objetivo. Caracterizar las proteínas hidrofílicas de superficie en Leishmania (Viannia panamensis. Materiales y métodos. Se amplificaron los genes hasp en L. (V. panamensis usando cebadores específicos para la especie Leishmania (Leishmania major. Los productos de la amplificación fueron clonados, secuenciados y analizados con herramientas bioinformáticas. Posteriormente, se realizó un análisis serológico por medio de ensayo inmunoabsorbente ligado a enzimas y Western blot para detectar la presencia de anticuerpos específicos contra las proteínas hidrofílicas recombinantes de superficie de L. (L. major en sueros de pacientes con leishmaniasis de zonas endémicas de Colombia. Resultados. Se encontró una copia de un pseudogen en L. (V. panamensis, el cual presentó una identidad del 60% con el gen haspa de L. (L. major. Sólo se encontraron anticuerpos contra las proteínas recombinantes de superficie hidrofílicas en sueros de pacientes con leishmaniasis visceral. Conclusión. Estos resultados sugieren que no existe ninguna copia de un gen funcional hasp en L. (V. panamensis, lo que indica una pérdida de la familia de genes en esta especie de Leishmania perteneciente al subgénero Viannia.

Characterization of Leishmania Soluble Exo-Antigen

National Research Council Canada - National Science Library

Cui, Liwang

2003-01-01

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

Wheat straw lignin degradation induction to aromatics by por Aspergillus spp. and Penicillium chrysogenum

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Baltierra-Trejo Eduardo

2016-02-01

Full Text Available Wheat straw is a recalcitrant agricultural waste; incineration of this material represents an important environmental impact. Different reports have been made regarding the use of the structural components of wheat straw, i.e. cellulose, hemicellulose and lignin; however, lignin has been less exploited because it is largely considered the recalcitrant part. Residual wheat straw lignin (REWSLI has a potential biotech-nological value if depolymerization is attained to produce aromatics. Ligninolytic mitosporic fungus represent an alternative where very little research has been done, even though they are capable of depol-ymerize REWSLI in simple nutritional conditions in relatively short periods, when compared to basidio-mycetes. The aim of this research was to study the depolymerization activity of Aspergillus spp and Penicillium spp on semipurified REWSLI as the sole carbon source to produce aromatics. The depoly-merization capacity was determined by the activity of the laccase, lignin peroxidase and manganese peroxidase enzymes. The generated aromatics derived from the REWSLI depolymerization were identi-fied by gas chromatography. Obtained results revealed that Penicillium chrysogenum depolymerized the lignin material by 34.8% during the 28-day experimentation period. Laccase activity showed the largest activity with 111 U L-1 in a seven-day period, this enzyme induction was detected in a smaller period than that required by basidiomycetes to induce it. Moreover, the enzymatic activity was produced with-out the addition of an extra carbon source as metabolic inductor. Aspergillus spp and Penicillium spp generated guaiacol, vanillin, and hydroxybenzoic, vanillinic, syringic and ferulic acid with a maximum weekly production of 3.5, 3.3, 3.2, 3.3, 10.1 and 21.9 mg mL-1, respectively.

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

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Miriam Berzunza-Cruz

2015-01-01

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

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

Science.gov (United States)

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

2015-01-01

Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

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

OpenAIRE

Aldair Junio Woyames Pinto

2011-01-01

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

Anti-Leishmania and cytotoxic activities of perillaldehyde epoxide synthetic positional isomers.

Science.gov (United States)

Keesen, Tatjana Souza Lima; da Silva, Larisse Virgolino; da Câmara Rocha, Juliana; Andrade, Luciana Nalone; Lima, Tamires Cardoso; de Sousa, Damião Pergentino

2018-03-13

Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC 50  = 3.8 μg.mL -1 ) was 16-fold more potent than its isomer EPER-1 (IC 50  = 64.6 μg.mL -1 ). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC 50  > 400 μg.mL -1 ) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies.

Leishmania exosomes and other virulence factors: Impact on innate immune response and macrophage functions.

Science.gov (United States)

Atayde, Vanessa Diniz; Hassani, Kasra; da Silva Lira Filho, Alonso; Borges, Andrezza Raposo; Adhikari, Anupam; Martel, Caroline; Olivier, Martin

2016-11-01

Leishmania parasites are the causative agents of the leishmaniases, a collection of vector-borne diseases that range from simple cutaneous to fatal visceral forms. Employing potent immune modulation mechanisms, Leishmania is able to render the host macrophage inactive and persist inside its phagolysosome. In the last few years, the role of exosomes in Leishmania-host interactions has been increasingly investigated. For instance, it was reported that Leishmania exosome release is augmented following temperature shift, a condition mimicking parasite's entry into its mammalian host. Leishmania exosomes were found to strongly affect macrophage cell signaling and functions, similarly to whole parasites. Importantly, these vesicles were shown to be pro-inflammatory, capable to recruit neutrophils at their inoculation site exacerbating the pathology. In this review, we provide the most recent insights on the role of exosomes and other virulence factors, especially the surface protease GP63, in Leishmania-host interactions, deepening our knowledge on leishmaniasis and paving the way for the development of new therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification

Science.gov (United States)

Vikeved, Elisabet; Backlund, Anders; Alsmark, Cecilia

2016-01-01

Background The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT). Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania. Methodology/Principal Findings To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species. Conclusions/Significance LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets. PMID:26730948

The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification.

Science.gov (United States)

Vikeved, Elisabet; Backlund, Anders; Alsmark, Cecilia

2016-01-01

The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT). Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania. To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species. LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification.

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Elisabet Vikeved

2016-01-01

Full Text Available The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT. Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania.To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species.LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

Evidência de transmissão de leishmaniose visceral por Lutzomyia cruzi no município de Jaciara, Estado de Mato Grosso, Brasil

OpenAIRE

Missawa, Nanci Akemi; Veloso, Márcia Aurélia Esser; Maciel, Giovana Belem Moreira Lima; Michalsky, Érika Monteiro; Dias, Edelberto Santos

2011-01-01

INTRODUÇÃO: O município de Jaciara foi classificado em 2003, como área de transmissão de leishmaniose visceral em situação de surto. O trabalho objetivou determinar evidência de transmissão de Leishmania (Leishmania) infantum chagasi por Lutzomyia cruzi no município de Jaciara, Estado de Mato Grosso, Brasil. MÉTODOS: O município situa-se a 127km da capital Cuiabá e é um importante ponto de atração para os praticantes de eco-turismo. Fêmeas de Lutzomyia cruzi, capturadas com armadilha de CDC, ...

Remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. na Estação de Tratamento de Esgoto Garcia, no município de Blumenau, SC, Brasil

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Mauro Giovanni Miglioli

2017-12-01

Full Text Available Giardia spp. e Cryptosporidium spp. são agentes etiológicos responsáveis por uma série de epidemias de gastroenterites ocorridas, principalmente, após o consumo de água contaminada. Os cistos e oocistos destes protozoários são resistentes às variações ambientais, bem como a maioria dos processos físicos, químicos e microbiológicos utilizados nas estações de tratamento de água e esgoto. Deste modo, este estudo teve como objetivo detectar e avaliar a remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. no sistema de tratamento combinado anaeróbio + aeróbio da ETE Garcia em Blumenau, SC. Para efetuar a detecção de cistos e oocistos, as amostras de efluentes e lodos provenientes da ETE foram concentradas através de filtração em membranas de ésteres de celulose e centrifugação, seguida por reação de imunofluorescência direta (RID utilizando o Kit diagnóstico - Merifluor. Para a obtenção dos parâmetros físicos, químicos e microbiológicos, as análises seguiram os padrões preconizados em APHA (2012. Concentrações elevadas de cistos de Giardia spp. (máx. 900.000 cistos L-1 foram detectadas em 83,3% dos pontos analisados. Oocistos de Cryptosporidium spp. também foram detectados em elevadas concentrações (máx. 300.000 oocistos L-1 em 66,6% dos pontos analisados. Não foram detectados cistos e oocistos nas amostras do efluente tratado, deste modo o sistema combinado da ETE Garcia apresentou uma eficiência >99,9% para a remoção das formas resistentes destes patógenos, contribuindo para a redução da contaminação ambiental por protozoários patogênicos presentes no esgoto doméstico do município de Blumenau, SC, Brasil.

Natural hybrid of Leishmania infantum/L. donovani: development in Phlebotomus tobbi, P. perniciosus and Lutzomyia longipalpis and comparison with non-hybrid strains differing in tissue tropism.

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Seblova, Veronika; Myskova, Jitka; Hlavacova, Jana; Votypka, Jan; Antoniou, Maria; Volf, Petr

2015-11-25

from Cyprus, however, in all other parameters studied, including localization of infection and colonization of stomodeal valve, dermotropic and viscerotropic strains were not significantly different. We showed high susceptibility of P. tobbi to various Leishmania spp. This, together with the presence of O-glycosylated midgut proteins in their midguts demonstrate that P. tobbi is a permissive vector. Two dermotropic and three viscerotropic strains from the L. donovani complex developed late-stage infections in natural L. infantum vectors, P. perniciosus and L. longipalpis and none of the parameters studied seem to be linked with different tropism of parasites in the vertebrate host.

Further support for a palaearctic origin of Leishmania

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Sara F Kerr

2000-08-01

Full Text Available The fossil record and systematics of murid rodents, reservoirs of zoonotic cutaneous leishmaniasis in the Palaearctic, Oriental, African, Nearctic and Neotropical, strongly support a Palaearctic origin of Leishmania. The fossil record and systematics of phlebotomine sand flies reinforce this idea. Interpretations of molecular data that place the origin of Leishmania in the Neotropical are inconsistent with the natural histories of reservoirs and vectors. The evolutionary pattern of New World rats (Sigmodontinae indicates that they may be the most important reservoirs of zoonotic cutaneous leishmaniasis throughout their range.

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

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

2013-01-01

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

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

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Klinger Antonio da Franca Rodrigues

2013-01-01

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

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

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

2013-01-01

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

Efecto del estrés por sequía en el desarrollo de la antracnosis en tres ecotipos de Stylosanthes spp.

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Nuñez Luis E.

1986-09-01

Full Text Available En condiciones de invernadero, se evaluó el efecto del estrés por segura sobre la incidencia y severidad de antracnosis, causada por C. gloesporioides en S. guianensis var. guianensis CIAT 136, var pauciflora CIAT 1283 y S. capitata CIAT 1315; al mismo tiempo se estudió las diferentes respuestas morfológicas y fisiológicas de los tres ecotipos bajo déficit de agua en el suelo y presión del patógeno. Los ecotipos de Stylosanthes estudiados no solo toleran la deshidratación (- 26 bares sino también exhiben importantes mecanismos de adaptación morfológica que tienden a evitarla. EI efecto aditivo del estrés causado por antracnosis en condiciones de sequía, afectó la persistencia de los ecotipos de Stylosanthes spp. más susceptibles.

Under glasshouse conditiones, the effect of drought stress on the incidence and severity of antracnosis, caused by C. gloeosporioides, in S. guianensis var. guianensis CIAT 136, var. pauciflora CIAT 1283 and in S. capitata CIAT 1315 was evaluated; at the same time, the different morphological and physiological response of the three ecotypes under deficiency of water in the soil and pathogen pressure were studied. The ecotypes of Stylosanthes studies not only tolerate dehydration (- 26 bares but also shoved important mechanisms of morphological adaptation that they have to avoid it. The additive effect of stress caused by antracnose in drought conditions affected the persistence of more susceptible ecotypes.

Large-Scale Investigation of Leishmania Interaction Networks with Host Extracellular Matrix by Surface Plasmon Resonance Imaging

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Fatoux-Ardore, Marie; Peysselon, Franck; Weiss, Anthony; Bastien, Patrick; Pratlong, Francine

2014-01-01

We have set up an assay to study the interactions of live pathogens with their hosts by using protein and glycosaminoglycan arrays probed by surface plasmon resonance imaging. We have used this assay to characterize the interactions of Leishmania promastigotes with ∼70 mammalian host biomolecules (extracellular proteins, glycosaminoglycans, growth factors, cell surface receptors). We have identified, in total, 27 new partners (23 proteins, 4 glycosaminoglycans) of procyclic promastigotes of six Leishmania species and 18 partners (15 proteins, 3 glycosaminoglycans) of three species of stationary-phase promastigotes for all the strains tested. The diversity of the interaction repertoires of Leishmania parasites reflects their dynamic and complex interplay with their mammalian hosts, which depends mostly on the species and strains of Leishmania. Stationary-phase Leishmania parasites target extracellular matrix proteins and glycosaminoglycans, which are highly connected in the extracellular interaction network. Heparin and heparan sulfate bind to most Leishmania strains tested, and 6-O-sulfate groups play a crucial role in these interactions. Numerous Leishmania strains bind to tropoelastin, and some strains are even able to degrade it. Several strains interact with collagen VI, which is expressed by macrophages. Most Leishmania promastigotes interact with several regulators of angiogenesis, including antiangiogenic factors (endostatin, anastellin) and proangiogenic factors (ECM-1, VEGF, and TEM8 [also known as anthrax toxin receptor 1]), which are regulated by hypoxia. Since hypoxia modulates the infection of macrophages by the parasites, these interactions might influence the infection of host cells by Leishmania. PMID:24478075

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

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Marta Chagas Monteiro

2005-06-01

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

Sintomas da injúria por frio em Heliconia spp

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GUSTAVO JONNAS S. M. BEZERRA

2008-07-01

Full Text Available As helicônias, entre as flores tropicais, têm se destacado no mercado internacional (Europa e Estados Unidos devido à beleza, diversidade de cores e formas e durabilidade. No entanto, para a comercialização a longas distâncias é necessário adotar formas de transporte que inibam o processo de senescência das flores e conservem a qualidade pós-colheita. O transporte de flores em temperaturas baixas é o mais utilizado, no entanto, em “flores tropicais” podem causar danos de injúria por frio. O objetivo deste trabalho foi descrever os sintomas causados pela injúria por frio em hastes florais de três genótipos de helicônia (H. bihai, H. wagneriana e H. caribaea x H. bihai cv. Carib Flame. As hastes florais de helicônia foram submetidas, por 72 horas, a três condições de temperatura: refrigerador expositor (2 ºC em caixa de papelão (embalagem padrão para transporte; refrigerador expositor (2 ºC sem caixa de papelão; e laboratório a 25 ºC e U.R. 60% (testemunha. O delineamento experimental utilizado foi o inteiramente casualizado, com três tratamentos e sete repetições na primeira avaliação e cinco repetições na segunda avaliação. Os sintomas da injúria por frio foram descritos a partir da comparação do aspecto visual das hastes florais submetidas a 2 °C com as testemunhas. A temperatura de 2 ºC, com ou sem a embalagem de transporte, provocou sintomas como: aspecto de queimadura no centro das brácteas, manchas escurecidas na área de inserção das brácteas na ráquis e murchamento das extremidades dos pecíolos das folhas e da base das inflorescências.

Species-Specific Antimonial Sensitivity in Leishmania Is Driven by Post-Transcriptional Regulation of AQP1

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Mandal, Goutam; Mandal, Srotoswati; Sharma, Mansi; Charret, Karen Santos; Papadopoulou, Barbara; Bhattacharjee, Hiranmoy; Mukhopadhyay, Rita

2015-01-01

Leishmania is a digenetic protozoan parasite causing leishmaniasis in humans. The different clinical forms of leishmaniasis are caused by more than twenty species of Leishmania that are transmitted by nearly thirty species of phlebotomine sand flies. Pentavalent antimonials (such as Pentostam or Glucantime) are the first line drugs for treating leishmaniasis. Recent studies suggest that pentavalent antimony (Sb(V)) acts as a pro-drug, which is converted to the more active trivalent form (Sb(III)). However, sensitivity to trivalent antimony varies among different Leishmania species. In general, Leishmania species causing cutaneous leishmaniasis (CL) are more sensitive to Sb(III) than the species responsible for visceral leishmaniasis (VL). Leishmania aquaglyceroporin (AQP1) facilitates the adventitious passage of antimonite down a concentration gradient. In this study, we show that Leishmania species causing CL accumulate more antimonite, and therefore exhibit higher sensitivity to antimonials, than the species responsible for VL. This species-specific differential sensitivity to antimonite is directly proportional to the expression levels of AQP1 mRNA. We show that the stability of AQP1 mRNA in different Leishmania species is regulated by their respective 3’-untranslated regions. The differential regulation of AQP1 mRNA explains the distinct antimonial sensitivity of each species. PMID:25714343

Differential Activation of Human Keratinocytes by Leishmania Species Causing Localized or Disseminated Disease.

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Scorza, Breanna M; Wacker, Mark A; Messingham, Kelly; Kim, Peter; Klingelhutz, Aloysius; Fairley, Janet; Wilson, Mary E

2017-10-01

All Leishmania species parasites are introduced into mammalian skin through a sand fly bite, but different species cause distinct clinical outcomes. Mouse studies suggest that early responses are critical determinants of subsequent adaptive immunity in leishmaniasis, yet few studies address the role of keratinocytes, the most abundant cell in the epidermis. We hypothesized that Leishmania infection causes keratinocytes to produce immunomodulatory factors that influence the outcome of infection. Incubation of primary or immortalized human keratinocytes with Leishmania infantum or Leishmania major, which cause visceral or cutaneous leishmaniasis, respectively, elicited dramatically different responses. Keratinocytes incubated with L. infantum significantly increased expression of proinflammatory genes for IL-6, IL-8, tumor necrosis factor, and IL-1B, whereas keratinocytes exposed to several L. major isolates did not. Furthermore, keratinocyte-monocyte co-incubation studies across a 4 µM semipermeable membrane suggested that L. infantum-exposed keratinocytes release soluble factors that enhance monocyte control of intracellular L. infantum replication (P Leishmania species that may affect the course of disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil.

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Carreira, João Carlos Araujo; da Silva, Alba Valéria Machado; de Pita Pereira, Daniela; Brazil, Reginaldo Peçanha

2012-06-07

The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot hybridization using a L. infantum

Progress towards a Leishmania vaccine.

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Tabbara, Khaled S

2006-07-01

Leishmaniasis is a vector-born protozoan disease. Approximately 12 million individuals are affected worldwide with an estimated annual incidence of 1.5-2 million. Two clinical manifestations are recognized, cutaneous, and visceral, both of which are common in the Middle East. In both forms, infection is chronic, with potential deformities, persistence following cure, and lifelong risk of reactivation. Attempts to develop an effective human Leishmania vaccine have not yet succeeded. Leishmanization, a crude form of live vaccination historically originated in this part of the world. Experimental vaccination has been extensively studied in model animals in the past 2 decades. In this review, major human killed vaccine trials are surveyed, and modern trends in Leishmania vaccine development, including subunit vaccines, naked DNA vaccines, and transmission blocking vaccines are explored. Recent findings of a link between persistence of live parasites, and maintenance of long-term immunity suggest live vaccination with attenuated strains, as a future vaccination strategy.

Development of a dipstick assay for detection of Leishmania-specific canine antibodies

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Schallig, Henk D. F. H.; Cardoso, Luís; Hommers, Marieke; Kroon, Nel; Belling, Guus; Rodrigues, Manuela; Semião-Santos, Saul J.; Vetter, Hans

2004-01-01

A dipstick assay, based on Leishmania infantum antigen, for the rapid detection of Leishmania-specific antibodies in canine serum samples was developed and evaluated. After determination of optimal dipstick test conditions, test performance was compared with two existing serological tests, i.e., the

An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

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Márcia Cristina Aquino Teixeira

2011-03-01

Full Text Available Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

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

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

2017-05-01

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

The flagellar protein FLAG1/SMP1 is a candidate for Leishmania-sand fly interaction.

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Di-Blasi, Tatiana; Lobo, Amanda R; Nascimento, Luanda M; Córdova-Rojas, Jose L; Pestana, Karen; Marín-Villa, Marcel; Tempone, Antonio J; Telleria, Erich L; Ramalho-Ortigão, Marcelo; McMahon-Pratt, Diane; Traub-Csekö, Yara M

2015-03-01

Leishmaniasis is a serious problem that affects mostly poor countries. Various species of Leishmania are the agents of the disease, which take different clinical manifestations. The parasite is transmitted by sandflies, predominantly from the Phlebotomus genus in the Old World and Lutzomyia in the New World. During development in the gut, Leishmania must survive various challenges, which include avoiding being expelled with blood remnants after digestion. It is believed that attachment to the gut epithelium is a necessary step for vector infection, and molecules from parasites and sand flies have been implicated in this attachment. In previous work, monoclonal antibodies were produced against Leishmania. Among these an antibody was obtained against Leishmania braziliensis flagella, which blocked the attachment of Leishmania panamensis flagella to Phlebotomus papatasi guts. The protein recognized by this antibody was identified and named FLAG1, and the complete FLAG1 gene sequence was obtained. This protein was later independently identified as a small, myristoylated protein and called SMP1, so from now on it will be denominated FLAG1/SMP1. The FLAG1/SMP1 gene is expressed in all developmental stages of the parasite, but has higher expression in promastigotes. The anti-FLAG1/SMP1 antibody recognized the flagellum of all Leishmania species tested and generated the expected band by western blots. This antibody was used in attachment and infection blocking experiments. Using the New World vector Lutzomyia longipalpis and Leishmania infantum chagasi, no inhibition of attachment ex vivo or infection in vivo was seen. On the other hand, when the Old World vectors P. papatasi and Leishmania major were used, a significant decrease of both attachment and infection were seen in the presence of the antibody. We propose that FLAG1/SMP1 is involved in the attachment/infection of Leishmania in the strict vector P. papatasi and not the permissive vector L. longipalpis.

Severity of tegumentary leishmaniasis is not exclusively associated with Leishmania RNA virus 1 infection in Brazil

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Luiza de Oliveira Ramos Pereira

2013-08-01

Full Text Available Leishmania RNA virus (LRV has been shown to be a symbiotic component of Leishmania parasites in South America. Nested retro-transcription polymerase chain reaction was employed to investigate LRV1 presence in leishmaniasis lesions from Brazil. In endemic areas of Rio de Janeiro (RJ, no LRV1 infection was observed even with mucosal involvement. LRV1 was only detected in Leishmania (V. guyanensis cutaneous lesions from the northern region, which were obtained from patients presenting with disease reactivation after clinical cure of their primary lesions. Our results indicated that the severity of leishmaniasis in some areas of RJ, where Leishmania (V. brazi-liensis is the primary etiological agent, was not associated with Leishmania LRV1 infection.

Evaluation of four molecular methods to detect Leishmania infection in dogs.

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Albuquerque, Andreia; Campino, Lenea; Cardoso, Luís; Cortes, Sofia

2017-03-13

Canine leishmaniasis, a zoonotic disease caused by Leishmania infantum vectored by phlebotomine sand flies, is considered a relevant veterinary and public health problem in various countries, namely in the Mediterranean basin and Brazil, where dogs are considered the main reservoir hosts. Not only diseased dogs but also those subclinically infected play a relevant role in the transmission of L. infantum to vectors; therefore, early diagnosis is essential, under both a clinical and an epidemiological perspective. Molecular tools can be a more accurate and sensitive approach for diagnosis, with a wide range of protocols currently in use. The aim of the present report was to compare four PCR based protocols for the diagnosis of canine Leishmania infection in a cohort of dogs from the Douro region, Portugal. A total of 229 bone marrow samples were collected from dogs living in the Douro region, an endemic region for leishmaniasis. Four PCR protocols were evaluated for Leishmania DNA detection in canine samples, three single (ITS1-PCR, MC-PCR and Uni21/Lmj4-PCR) and one nested (nested SSU rRNA-PCR). Two of the protocols were based on nuclear targets and the other two on kinetoplastid targets. The higher overall percentage of infected dogs was detected with the nested SSU rRNA-PCR (37.6%), which also was able to detect Leishmania DNA in a higher number of samples from apparently healthy dogs (25.3%). The ITS1-PCR presented the lowest level of Leishmania detection. Nested SSU rRNA-PCR is an appropriate method to detect Leishmania infection in dogs. Accurate and early diagnosis in clinically suspect as well as apparently healthy dogs is essential, in order to treat and protect animals and public health and contribute to the control and awareness of the disease.

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

Science.gov (United States)

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

2006-01-01

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

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

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Filipe Dantas-Torres

2006-08-01

ão 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.

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

Science.gov (United States)

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

2017-01-11

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

Identificación de una nueva proteína en Leishmania (Viannia peruviana

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Maxy De los Santos

1998-01-01

Full Text Available El análisis de la secuencia nucleotídica y aminoacídica de un clon de la biblioteca de expresión en fago λgt11 de Leishmania (Viannia peruviana, estableció identidad parcial con los genes de las proteínas acídicas ribosomales P2 de Leishmania (Leishmania infantum. Este hallazgo unido a ciertos dominios geonómicos conservados, sugeridos de la comparación de 14 secuencias de otras proteínas P1 eucarióticas, confirman que la secuencia del inserto de clon codifica la proteína acídica ribosomal P1 de L. (V. peruviana denominada LpP1. Este es el primer reporte sobre este tipo de proteína en el género Leishmania.

Mitochondrial associated ubiquitin fold modifier-1 mediated protein conjugation in Leishmania donovani.

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Sreenivas Gannavaram

2011-01-01

Full Text Available In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1 and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2 specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.

Efeito do uso de bactérias probióticas na sobrevivência de larvas de Litopenaeus vannamei expostas à infecção experimental por Vibrio spp.

OpenAIRE

Joana Angélica Lyra Vogeley de Carvalho

2011-01-01

O presente estudo teve como objetivo avaliar a sobrevivência de larvas de Litopenaeus vannamei tratadas com bactérias probióticas e posteriormente infectadas por Vibrio harveyi e Vibrio alginolyticus. Os camarões foram mantidos em dois tanques de 80L nas mesmas condições, mas apenas um deles foi previamente tratado com probiótico comercial (Bacillus spp.) adicionado diariamente na água na concentração de 105 UFC/ml. Este protocolo foi mantido até os animais alcançarem o estágio de desen...

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

International Nuclear Information System (INIS)

Lourenco, Cecilia de Oliveira

2000-01-01

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

Helicobacter spp. infection in dogs is not associated with changes in epithelial proliferation or E-cadherin expression in gastric mucosaInfecção por Helicobacter spp. em cães não está associada com alterações na proliferação epitelial ou na expressão de E-caderina na mucosa gástrica

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Ana Paula Bracarense

2012-02-01

Full Text Available Helicobacter pylori infection causes gastritis and can induce gastric adenocarcinoma and MALT lymphoma in humans. The aim of this study was to determine in dogs whether there is an association between Helicobacter spp. infection in gastric mucosa, histological lesions, including epithelial cell proliferation and cell adhesion. Gastric biopsies of 12 dogs with gastric disturbances and 25 healthy dogs were evaluated. Warthin-Starry staining (WS and PCR assay were performed to confirm the presence of helicobacteria. The Helicobacter species were determined by PCR assay with speciesspecific primers for H. heilmannii, H. bizzozeronii or H. salomonis, H. felis and H. pylori. Mucosal lesions were evaluated by haematoxylin and eosin (HE and epithelial proliferation was determined by AgNOR and PCNA methods. Cell adhesion was evaluated by the expression of E-cadherin by epithelial cells. Helicobacter spp. was confirmed in 75.7% (28/37 and 73.0% (27/37 of the samples by WS and PCR, respectively. H. bizzozeronii was the species most frequently detected (37%; co-infection was observed in six (22% dogs. Histological changes in the lamina propria included mild chronic gastritis, fibrosis, glandular degeneration, and presence of lymphoid aggregates. There was a significant association between H. heilmannii infection and the presence of lymphoid follicles (p Infecção por Helicobacter pylori provoca gastrite e pode induzir adenocarcinoma gástrico e linfoma tipo MALT em seres humanos. O objetivo deste estudo foi determinar se existe associação entre infecção por Helicobacter spp. na mucosa gástrica de cães e lesões histológicas, incluindo proliferação epitelial e adesão celular. Foram avaliadas biópsias de 12 cães com distúrbios gástricos e de 25 cães saudáveis. A coloração de Warthin-Starry (WS e o método de PCR foram utilizados para confirmar a presença de helicobactérias. As espécies de Helicobacter foram determinadas por PCR com

INFECTIOUS KERATOCONJUNTIVITIS OUTBREAK IN OVINES DUE TO Moraxella spp IN STATE OF GOIÁS, BRAZIL SURTO DE CERATOCONJUNTIVITE INFECCIOSA EM OVINOS CAUSADA POR Moraxella spp. NO ESTADO DE GOIÁS, BRASIL

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Nilo Sérgio Troncoso Chaves

2008-04-01

','serif'">Moraxella spp foi feito por meio de cultura nos Laboratórios de Microbiologia do Centro de Pesquisa de Alimentos da Escola de Veterinária da Universidade Federal de Goiás (APA/EV-UFG e do Departamento de Medicina Veterinária da Escola de Veterinária da Universidade Federal de Goiás (DMV/EV-UFG. O controle do foco na propriedade envolveu os protocolos: 1. higiênico, com o isolamento em ambiente de pouca luminosidade, repouso e alimentação adequada;  2. medicamentoso, mediante o uso de solução fisiológica 0,9% para a lavagem dos olhos, pomada oftálmica de cloridrato de oxitetraciclina para uso local e cloridrato de oxitetraciclina LA injetável, tanto para os animais doentes como para o restante do rebanho;  3. profilático, por meio de vacina comercial contra a ceratoconjuntive infeciosa e combate às moscas. A recuperação da maioria dos animais minimizou as perdas econômicas e evitou a disseminação da enfermidade na propriedade e para outras fazendas. No Brasil, existem poucos estudos a respeito de surtos de CCI em ovinos, o que motivou a realização deste trabalho, diante da escassez de informações sobre essa doença ocular, causada pela Moraxella spp, em ovinos, no estado de Goiás, Brasil

Recuento y determinación de viabilidad de giardia spp. y Cryptosporidium spp. en aguas potables y residuales en la cuenca alta del rio Bogotá.

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Marlén Andrea Alarcón

2005-09-01

Full Text Available Introducción. La transmisión de enfermedades de origen hídrico está relacionada con la contaminación de origen fecal en aguas residuales y potables. Estas enfermedades son causadas por la presencia de bacterias, virus y parásitos, los cuales generan altos porcentajes de morbimortalidad, especialmente, en la población infantil. Se han seleccionado Giardia spp. y Cryptosporidium spp. como organismos indicadores de contaminación de origen parasitario y su análisis es útil para evaluar la calidad del agua y determinar el riesgo sanitario. En Colombia se conoce poco sobre la presencia y la concentración de estos parásitos en aguas, razón por la cual es importante continuar su estudio. Objetivo. El objetivo de este trabajo fue evaluar la presencia de estos protozoos en cinco estaciones de muestreo de la cuenca alta del río Bogotá y en dos sistemas de potabilización de la misma área. Materiales y métodos. Las técnicas aplicadas para la determinación y el recuento de las formas quísticas fueron: floculación inorgánica para aguas residuales, filtración para aguas potables y pruebas de colorantes vitales para viabilidad. Resultados. Se confirmó la presencia de Cryptosporidium spp. en dos de las estaciones del río Bogotá y en las dos potabilizadoras. Giardia spp. se encontró en las dos potabilizadoras pero no en el río Bogotá. La viabilidad fue positiva para Cryptosporidium spp. en una muestra proveniente del río, y negativa para las muestras de agua potable. Conclusiones. Estos resultados muestran la presencia de protozoos en aguas potables y residuales lo cual puede generar riesgo sanitario para la población de dicha zona.

Detection of Leishmania donovani and L. tropica in ethiopian wild rodents

Czech Academy of Sciences Publication Activity Database

Kassahun, A.; Sádlová, J.; Dvořák, V.; Košťálová, T.; Rohoušová, I.; Frynta, D.; Aghová, Tatiana; Yasur-Landau, D.; Lemma, W.; Hailu, A.; Baneth, G.; Warburg, A.; Volf, P.; Votýpka, J.

2015-01-01

Roč. 145, May 2015 (2015), s. 39-44 ISSN 0001-706X R&D Projects: GA ČR GAP506/10/0983 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Leishmania donovani * Leishmania tropica * Phlebotomine sand fly * Rodents * kDNA * ITS1 Subject RIV: EG - Zoology Impact factor: 2.380, year: 2015

Impact of Leishmania metalloprotease GP63 on macrophage signaling

Science.gov (United States)

Isnard, Amandine; Shio, Marina T.; Olivier, Martin

2012-01-01

The intramacrophage protozoan parasites of Leishmania genus have developed sophisticated ways to subvert the innate immune response permitting their infection and propagation within the macrophages of the mammalian host. Several Leishmania virulence factors have been identified and found to be of importance for the development of leishmaniasis. However, recent findings are now further reinforcing the critical role played by the zinc-metalloprotease GP63 as a virulence factor that greatly influence host cell signaling mechanisms and related functions. GP63 has been found to be involved not only in the cleavage and degradation of various kinases and transcription factors, but also to be the major molecule modulating host negative regulatory mechanisms involving for instance protein tyrosine phosphatases (PTPs). Those latter being well recognized for their pivotal role in the regulation of a great number of signaling pathways. In this review article, we are providing a complete overview about the role of Leishmania GP63 in the mechanisms underlying the subversion of macrophage signaling and functions. PMID:22919663

Rattus norvegicus (Rodentia: Muridae Infected by Leishmania (Leishmania infantum (syn. Le. chagasi in Brazil

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Fabiana de Oliveira Lara-Silva

2014-01-01

Full Text Available In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL was also captured at high proportion (12.8%. Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Exosome Secretion by the Parasitic Protozoan Leishmania within the Sand Fly Midgut

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Vanessa Diniz Atayde

2015-11-01

Full Text Available Despite several studies describing the secretion of exosomes by Leishmania in vitro, observation of their formation and release in vivo has remained a major challenge. Herein, we show that Leishmania constitutively secretes exosomes within the lumen of the sand fly midgut through a mechanism homologous to the mammalian pathway. Through egestion experiments, we demonstrate that Leishmania exosomes are part of the sand fly inoculum and are co-egested with the parasite during the insect’s bite, possibly influencing the host infectious process. Indeed, co-inoculation of mice footpads with L. major plus midgut-isolated or in-vitro-isolated L. major exosomes resulted in a significant increase in footpad swelling. Notably, co-injections produced exacerbated lesions through overinduction of inflammatory cytokines, in particular IL-17a. Our data indicate that Leishmania exosomes are an integral part of the parasite’s infectious life cycle, and we propose to add these vesicles to the repertoire of virulence factors associated with vector-transmitted infections.

Methodology optimizing SAGE library tag-to-gene mapping: application to Leishmania

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Smandi Sondos

2012-01-01

Full Text Available Abstract Background Leishmaniasis are widespread parasitic-diseases with an urgent need for more active and less toxic drugs and for effective vaccines. Understanding the biology of the parasite especially in the context of host parasite interaction is a crucial step towards such improvements in therapy and control. Several experimental approaches including SAGE (Serial analysis of gene expression have been developed in order to investigate the parasite transcriptome organisation and plasticity. Usual SAGE tag-to-gene mapping techniques are inadequate because almost all tags are normally located in the 3'-UTR outside the CDS, whereas most information available for Leishmania transcripts is restricted to the CDS predictions. The aim of this work is to optimize a SAGE libraries tag-to-gene mapping technique and to show how this development improves the understanding of Leishmania transcriptome. Findings The in silico method implemented herein was based on mapping the tags to Leishmania genome using BLAST then mapping the tags to their gene using a data-driven probability distribution. This optimized tag-to-gene mappings improved the knowledge of Leishmania genome structure and transcription. It allowed analyzing the expression of a maximal number of Leishmania genes, the delimitation of the 3' UTR of 478 genes and the identification of biological processes that are differentially modulated during the promastigote to amastigote differentiation. Conclusion The developed method optimizes the assignment of SAGE tags in trypanosomatidae genomes as well as in any genome having polycistronic transcription and small intergenic regions.

Evolutionary comparison of prenylation pathway in kinetoplastid Leishmania and its sister Leptomonas.

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Chauhan, Indira Singh; Kaur, Jaspreet; Krishna, Shagun; Ghosh, Arpita; Singh, Prashant; Siddiqi, Mohammad Imran; Singh, Neeloo

2015-11-21

Leptomonas is monogenetic kinetoplastid parasite of insects and is primitive in comparison to Leishmania. Comparative studies of these two kinetoplastid may share light on the evolutionary transition to dixenous parasitism in Leishmania. In order to adapt and survive within two hosts, Leishmania species must have acquired virulence factors in addition to mechanisms that mediate susceptibility/resistance to infection in the pathology associated with disease. Rab proteins are key mediators of vesicle transport and contribute greatly to the evolution of complexity of membrane transport system. In this study we used our whole genome sequence data of these two divergent kinetoplastids to analyze the orthologues/paralogues of Rab proteins. During change of lifestyle from monogenetic (Leptomonas) to digenetic (Leishmania), we found that the prenyl machinery remained unchanged. Geranylgeranyl transferase-I (GGTase-I) was absent in both Leishmania and its sister Leptomonas. Farnesyltransferase (FTase) and geranylgeranyl transferase-II (GGTase-II) were identified for protein prenylation. We predict that activity of the missing alpha-subunit (α-subunit) of GGTase-II in Leptomonas was probably contributed by the α-subunit of FTase, while beta-subunit (β-subunit) of GGTase-II was conserved and indicated functional conservation in the evolution of these two kinetoplastids. Therefore the β-subunit emerges as an excellent target for compounds inhibiting parasite activity in clinical cases of co-infections. We also confirmed that during the evolution to digenetic life style in Leishmania, the parasite acquired capabilities to evade drug action and maintain parasite virulence in the host with the incorporation of short-chain dehydrogenase/reductase (SDR/MDR) superfamily in Rab genes. Our study based on whole genome sequences is the first to build comparative evolutionary analysis and identification of prenylation proteins in Leishmania and its sister Leptomonas. The information

Affinity labeling of the folate-methotrexate transporter from Leishmania donovani

International Nuclear Information System (INIS)

Beck, J.T.; Ullman, B.

1989-01-01

An affinity labeling technique has been developed to identify the folate-methotrexate transporter of Leishmania donovani promastigotes using activated derivatives of the ligands. These activated derivatives were synthesized by incubating folate and methotrexate with a 10-fold excess of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) for 10 min at ambient temperature in dimethyl sulfoxide. When intact wild-type (DI700) Leishmania donovani or preparations of their membranes were incubated with a 0.4 μM concentration of either activated [ 3 H]folate or activated [ 3 H]methotrexate, the radiolabeled ligands were covalently incorporated into a polypeptide with a molecular weight of approximately 46,000, as demonstrated by SDS-polyacrylamide gel electrophoresis. No affinity labeling of a 46,000-dalton protein was observed when equimolar concentrations of activated radiolabeled ligands were incubated with intact cells or membranes prepared from a methotrexate-resistant mutant clone of Leishmania donovani, MTXA5, that is genetically defective in folate-methotrexate transport capability. Time course studies indicated that maximal labeling of the 46,000-dalton protein occurred within 5-10 min of incubation of intact cells with activated ligand. These studies provide biochemical evidence that the folate-methotrexate transporter of Leishmania donovani can be identified in crude extracts by an affinity labeling technique and serve as a prerequisite to further analysis of the transport protein by providing a vehicle for subsequent purification of this membrane carrier. Moreover, these investigations suggest that the affinity labeling technique using EDC-activated ligands may be exploitable to analyze other cell surface binding proteins in Leishmania donovani, as well as in other organisms

Genomic confirmation of hybridisation and recent inbreeding in a vector-isolated Leishmania population.

Science.gov (United States)

Rogers, Matthew B; Downing, Tim; Smith, Barbara A; Imamura, Hideo; Sanders, Mandy; Svobodova, Milena; Volf, Petr; Berriman, Matthew; Cotton, James A; Smith, Deborah F

2014-01-01

Although asexual reproduction via clonal propagation has been proposed as the principal reproductive mechanism across parasitic protozoa of the Leishmania genus, sexual recombination has long been suspected, based on hybrid marker profiles detected in field isolates from different geographical locations. The recent experimental demonstration of a sexual cycle in Leishmania within sand flies has confirmed the occurrence of hybridisation, but knowledge of the parasite life cycle in the wild still remains limited. Here, we use whole genome sequencing to investigate the frequency of sexual reproduction in Leishmania, by sequencing the genomes of 11 Leishmania infantum isolates from sand flies and 1 patient isolate in a focus of cutaneous leishmaniasis in the Çukurova province of southeast Turkey. This is the first genome-wide examination of a vector-isolated population of Leishmania parasites. A genome-wide pattern of patchy heterozygosity and SNP density was observed both within individual strains and across the whole group. Comparisons with other Leishmania donovani complex genome sequences suggest that these isolates are derived from a single cross of two diverse strains with subsequent recombination within the population. This interpretation is supported by a statistical model of the genomic variability for each strain compared to the L. infantum reference genome strain as well as genome-wide scans for recombination within the population. Further analysis of these heterozygous blocks indicates that the two parents were phylogenetically distinct. Patterns of linkage disequilibrium indicate that this population reproduced primarily clonally following the original hybridisation event, but that some recombination also occurred. This observation allowed us to estimate the relative rates of sexual and asexual reproduction within this population, to our knowledge the first quantitative estimate of these events during the Leishmania life cycle.

Leishmania carbon metabolism in the macrophage phagolysosome- feast or famine?

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McConville, Malcolm J; Saunders, Eleanor C; Kloehn, Joachim; Dagley, Michael J

2015-01-01

A number of medically important microbial pathogens target and proliferate within macrophages and other phagocytic cells in their mammalian hosts. While the majority of these pathogens replicate within the host cell cytosol or non-hydrolytic vacuolar compartments, a few, including protists belonging to the genus Leishmania, proliferate long-term within mature lysosome compartments.  How these parasites achieve this feat remains poorly defined. In this review, we highlight recent studies that suggest that Leishmania virulence is intimately linked to programmed changes in the growth rate and carbon metabolism of the obligate intra-macrophage stages. We propose that activation of a slow growth and a stringent metabolic response confers resistance to multiple stresses (oxidative, temperature, pH), as well as both nutrient limitation and nutrient excess within this niche. These studies highlight the importance of metabolic processes as key virulence determinants in Leishmania.

Serological and molecular survey of Leishmania infection in dogs from Luanda, Angola

NARCIS (Netherlands)

Vilhena, Hugo; Granada, Sara; Oliveira, Ana Cristina; Schallig, Henk D. F. H.; Nachum-Biala, Yaarit; Cardoso, Luís; Baneth, Gad

2014-01-01

Canine leishmaniosis (CanL) due to Leishmania infantum is a global zoonosis endemic in more than 70 countries in Europe, North Africa, Asia and America; however, data on this infection is scarce from southern Africa. The aim of this study was to survey dogs in Luanda, Angola, for Leishmania

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

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Mimori Tatsuyuki

2006-09-01

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

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)

Lourenco, Cecilia de Oliveira

2000-07-01

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

A diagnostic assay based on variable intergenic region distinguishes between Leishmania donovani and Leishmania infantum

Czech Academy of Sciences Publication Activity Database

Chocholová, Eva; Jirků, Milan; Lukeš, Julius

2008-01-01

Roč. 55, č. 1 (2008), s. 75-78 ISSN 0015-5683 R&D Projects: GA MŠk LC07032; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : Leishmania * assay * diagnosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.307, year: 2008

Parasitism of Rhizoctonia solani by strains of Trichoderma spp. Parasitismo de Rhizoctonia solani por linhagens de Trichoderma spp.

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Itamar Soares de Melo

2000-03-01

Full Text Available Rhizoctonia solani causes serious diseases in a wide range of plant species. The fungus Trichoderma has been shown to be particularly effective in the control of the pathogen. Thus, this research was carried out to screen fourteen Trichoderma strains against R. solani in vitro. All strains tested inhibited the growth of R. solani. Three T. koningii strains produced toxic metabolites with strong activity against R. solani, inhibiting the mycelial growth by 79%. T. harzianum, Th-9 reduced the viability of sclerotia of R. solani by 81.8% and T. koningii, TK-5 reduced by 53%. Electron microscopic observations revealed that all T. harzianum strains interacted with R. solani. Th-9 grew toward and coiled around the host cells, penetrating and destroying the hyphae. Penetration of host cells was apparently accomplished by mechanical activity.Rhizoctonia solani é um dos mais destrutivos patógenos de plantas cultivadas. Métodos alternativos de controle têm sido empregados com sucesso, particularmente, utilizando-se o fungo Trichoderma. Este trabalho visou, portanto, selecionar linhagens efetivas desse micoparasita contra o patógeno. Onze linhagens de T. harzianum e três de T. koningii foram testadas in vitro com relação ao parasitismo de hifas e de escleródios e produção de metabólitos tóxicos. Todas as linhagens de Trichoderma spp. inibiram o crescimento miceliano de R. solani e as três linhagens de T. koningii produziram potentes antibióticos, que inibiram mais de 79% o crescimento do patógeno. Uma linhagem de T. harzianum, Th-9, reduziu a viabilidade dos escleródios em 81,8% e uma de T. koningii em 53%. Microscopia eletrônica de varredura revelou que todas as linhagens de T. harzianum parasitaram R. solani enquanto nenhuma linhagem de T. koningii interagiu com R. solani, possivelmente, devido à forte inibição causada pelos metabólitos que impediu o contato entre os dois fungos. T. harzianum, Th-9, cresceu ao redor, penetrou e

Leishmania development in sand flies: parasite-vector interactions overview.

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Dostálová, Anna; Volf, Petr

2012-12-03

Leishmaniases are vector-borne parasitic diseases with 0.9 - 1.4 million new human cases each year worldwide. In the vectorial part of the life-cycle, Leishmania development is confined to the digestive tract. During the first few days after blood feeding, natural barriers to Leishmania development include secreted proteolytic enzymes, the peritrophic matrix surrounding the ingested blood meal and sand fly immune reactions. As the blood digestion proceeds, parasites need to bind to the midgut epithelium to avoid being excreted with the blood remnant. This binding is strictly stage-dependent as it is a property of nectomonad and leptomonad forms only. While the attachment in specific vectors (P. papatasi, P. duboscqi and P. sergenti) involves lipophosphoglycan (LPG), this Leishmania molecule is not required for parasite attachment in other sand fly species experimentally permissive for various Leishmania. During late-stage infections, large numbers of parasites accumulate in the anterior midgut and produce filamentous proteophosphoglycan creating a gel-like plug physically obstructing the gut. The parasites attached to the stomodeal valve cause damage to the chitin lining and epithelial cells of the valve, interfering with its function and facilitating reflux of parasites from the midgut. Transformation to metacyclic stages highly infective for the vertebrate host is the other prerequisite for effective transmission. Here, we review the current state of knowledge of molecular interactions occurring in all these distinct phases of parasite colonization of the sand fly gut, highlighting recent discoveries in the field.

Natural infection of Didelphis aurita (Mammalia: Marsupialia with Leishmania infantum in Brazil

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Carreira João Carlos

2012-06-01

Full Text Available Abstract Background The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL. Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris, have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. Methods The opossums studied were caught by wire traps (Tomahawk in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Results Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6% and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed

Survey of wild mammal hosts of cutaneous leishmaniasis parasites in panamá and costa rica.

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González, Kadir; Calzada, José E; Saldaña, Azael; Rigg, Chystrie A; Alvarado, Gilbert; Rodríguez-Herrera, Bernal; Kitron, Uriel D; Adler, Gregory H; Gottdenker, Nicole L; Chaves, Luis Fernando; Baldi, Mario

2015-03-01

The eco-epidemiology of American cutaneous leishmaniasis (ACL) is driven by animal reservoir species that are a source of infection for sand flies that serve as vectors infecting humans with Leishmania spp parasites. The emergence and re-emergence of this disease across Latin America calls for further studies to identify reservoir species associated with enzootic transmission. Here, we present results from a survey of 52 individuals from 13 wild mammal species at endemic sites in Costa Rica and Panama where ACL mammal hosts have not been previously studied. For Leishmania spp. diagnostics we employed a novel PCR technique using blood samples collected on filter paper. We only found Leishmania spp parasites in one host, the two-toed sloth, Choloepus hoffmanni. Our findings add further support to the role of two-toed sloths as an important ACL reservoir in Central America.

Evaluation of a Microculture Method for Isolation of Leishmania Parasites from Cutaneous Lesions of Patients in Peru▿

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Boggild, Andrea K.; Miranda-Verastegui, Cesar; Espinosa, Diego; Arevalo, Jorge; Adaui, Vanessa; Tulliano, Gianfranco; Llanos-Cuentas, Alejandro; Low, Donald E.

2007-01-01

Traditional culture of Leishmania spp. is labor intensive and has poor sensitivity. We evaluated a microculture method for the diagnosis of cutaneous leishmaniasis in consecutive patients presenting to the Leishmaniasis Clinic at the Instituto de Medicina Tropical Alexander von Humboldt, Peru, for evaluation of skin lesions. Lesion aspirates were cultured in duplicate and parallel in traditional culture tubes containing modified Novy-MacNeal-Nicolle (NNN) medium or Roswell Park Memorial Institute medium 1640 with 10% fetal bovine serum (10% RPMI) and in 70-μl capillary tubes containing a mixture of lesion aspirate and 10% RPMI. For sensitivity analysis, the consensus standard was considered to be a positive result in any two of the following four tests: Giemsa-stained lesion smear, culture, kinetoplast DNA PCR, or leishmanin skin test. The outcome measures were sensitivity and time to culture positivity. Forty-five patients with 62 skin lesions were enrolled in the study, of which 53 lesions fulfilled the consensus criteria for a final diagnosis of cutaneous leishmaniasis. Of these 53 lesions, 39 were culture positive: 38 in capillary tubes, 29 in traditional culture tubes with modified NNN medium, and 19 in traditional culture tubes with 10% RPMI medium. The sensitivity of microculture was 71.7%, versus 54.7% for traditional culture with NNN (P, 0.038) and 35.8% with 10% RPMI (P, microculture, 5.2 days in NNN, and 6 days in 10% RPMI (P, 0.009). We have demonstrated that microculture is a more sensitive and time-efficient means of isolating Leishmania parasites from cutaneous lesions than traditional culture. PMID:17881557

Evaluation of a microculture method for isolation of Leishmania parasites from cutaneous lesions of patients in Peru.

Science.gov (United States)

Boggild, Andrea K; Miranda-Verastegui, Cesar; Espinosa, Diego; Arevalo, Jorge; Adaui, Vanessa; Tulliano, Gianfranco; Llanos-Cuentas, Alejandro; Low, Donald E

2007-11-01

Traditional culture of Leishmania spp. is labor intensive and has poor sensitivity. We evaluated a microculture method for the diagnosis of cutaneous leishmaniasis in consecutive patients presenting to the Leishmaniasis Clinic at the Instituto de Medicina Tropical Alexander von Humboldt, Peru, for evaluation of skin lesions. Lesion aspirates were cultured in duplicate and parallel in traditional culture tubes containing modified Novy-MacNeal-Nicolle (NNN) medium or Roswell Park Memorial Institute medium 1640 with 10% fetal bovine serum (10% RPMI) and in 70-microl capillary tubes containing a mixture of lesion aspirate and 10% RPMI. For sensitivity analysis, the consensus standard was considered to be a positive result in any two of the following four tests: Giemsa-stained lesion smear, culture, kinetoplast DNA PCR, or leishmanin skin test. The outcome measures were sensitivity and time to culture positivity. Forty-five patients with 62 skin lesions were enrolled in the study, of which 53 lesions fulfilled the consensus criteria for a final diagnosis of cutaneous leishmaniasis. Of these 53 lesions, 39 were culture positive: 38 in capillary tubes, 29 in traditional culture tubes with modified NNN medium, and 19 in traditional culture tubes with 10% RPMI medium. The sensitivity of microculture was 71.7%, versus 54.7% for traditional culture with NNN (P, 0.038) and 35.8% with 10% RPMI (P, microculture, 5.2 days in NNN, and 6 days in 10% RPMI (P, 0.009). We have demonstrated that microculture is a more sensitive and time-efficient means of isolating Leishmania parasites from cutaneous lesions than traditional culture.

Amastin Knockdown in Leishmania braziliensis Affects Parasite-Macrophage Interaction and Results in Impaired Viability of Intracellular Amastigotes.

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Rita Marcia Cardoso de Paiva

2015-12-01

Full Text Available Leishmaniasis, a human parasitic disease with manifestations ranging from cutaneous ulcerations to fatal visceral infection, is caused by several Leishmania species. These protozoan parasites replicate as extracellular, flagellated promastigotes in the gut of a sandfly vector and as amastigotes inside the parasitophorous vacuole of vertebrate host macrophages. Amastins are surface glycoproteins encoded by large gene families present in the genomes of several trypanosomatids and highly expressed in the intracellular amastigote stages of Trypanosoma cruzi and Leishmania spp. Here, we showed that the genome of L. braziliensis contains 52 amastin genes belonging to all four previously described amastin subfamilies and that the expression of members of all subfamilies is upregulated in L. braziliensis amastigotes. Although primary sequence alignments showed no homology to any known protein sequence, homology searches based on secondary structure predictions indicate that amastins are related to claudins, a group of proteins that are components of eukaryotic tight junction complexes. By knocking-down the expression of δ-amastins in L. braziliensis, their essential role during infection became evident. δ-amastin knockdown parasites showed impaired growth after in vitro infection of mouse macrophages and completely failed to produce infection when inoculated in BALB/c mice, an attenuated phenotype that was reverted by the re-expression of an RNAi-resistant amastin gene. Further highlighting their essential role in host-parasite interactions, electron microscopy analyses of macrophages infected with amastin knockdown parasites showed significant alterations in the tight contact that is normally observed between the surface of wild type amastigotes and the membrane of the parasitophorous vacuole.

PKC/ROS-Mediated NLRP3 Inflammasome Activation Is Attenuated by Leishmania Zinc-Metalloprotease during Infection

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Jung, Jee Yong; Chang, Kwang-Poo; Olivier, Martin

2015-01-01

Parasites of the Leishmania genus infect and survive within macrophages by inhibiting several microbicidal molecules, such as nitric oxide and pro-inflammatory cytokines. In this context, various species of Leishmania have been reported to inhibit or reduce the production of IL-1β both in vitro and in vivo. However, the mechanism whereby Leishmania parasites are able to affect IL-1β production and secretion by macrophages is still not fully understood. Dependent on the stimulus at hand, the maturation of IL-1β is facilitated by different inflammasome complexes. The NLRP3 inflammasome has been shown to be of pivotal importance in the detection of danger molecules such as inorganic crystals like asbestos, silica and malarial hemozoin, (HZ) as well as infectious agents. In the present work, we investigated whether Leishmania parasites modulate NLRP3 inflammasome activation. Using PMA-differentiated THP-1 cells, we demonstrate that Leishmania infection effectively inhibits macrophage IL-1β production upon stimulation. In this context, the expression and activity of the metalloprotease GP63 - a critical virulence factor expressed by all infectious Leishmania species - is a prerequisite for a Leishmania-mediated reduction of IL-1β secretion. Accordingly, L. mexicana, purified GP63 and GP63-containing exosomes, caused the inhibition of macrophage IL-1β production. Leishmania-dependent suppression of IL-1β secretion is accompanied by an inhibition of reactive oxygen species (ROS) production that has previously been shown to be associated with NLRP3 inflammasome activation. The observed loss of ROS production was due to an impaired PKC-mediated protein phosphorylation. Furthermore, ROS-independent inflammasome activation was inhibited, possibly due to an observed GP63-dependent cleavage of inflammasome and inflammasome-related proteins. Collectively for the first time, we herein provide evidence that the protozoan parasite Leishmania, through its surface

Factors associated with Leishmania chagasi infection in domestic dogs from Teresina, State of Piauí, Brazil Fatores associados à infecção por Leishmania chagasi em cães domiciliados de Teresina, Estado do Piauí, Brasil

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João Pereira da Silva

2012-08-01

Full Text Available INTRODUCTION: Many studies have evaluated risk factors for human visceral leishmaniasis, but few have focused on the infection among dogs. The objective of this study was to assess the association between peridomestic socioeconomic and environmental factors and the presence of dogs seropositive for Leishmania chagasi in the City of Teresina, Brazil. METHODS: This case-control study was based on the results of a routine seroepidemiological survey among domestic dogs carried out in 2007. Serological tests were performed by means of indirect immunofluorescence antibody test. All dwellings in which at least one seropositive dog was detected were considered cases, and controls were a random sample of dwellings in which only seronegative dogs were identified. Associations between variables were expressed as odds ratios (OR and their respective 95% confidence intervals (95%CI estimated using multivariate logistic regression. RESULTS: Dwellings with a history of dogs removed by the visceral leishmaniasis control program in the last 12 months had five-fold higher odds of having at least one seropositive dog as compared with dwellings having no history of dog removal (OR = 5.19; 95%CI = 3.20-8.42. Dwellings with cats had 58% increased odds of dog infection as compared with those having no cats (OR = 1.58; 95%CI = 1.01-2.47. CONCLUSIONS: Identification of factors associated with canine visceral leishmaniasis might be used for the delimitation of areas of higher risk for human visceral leishmaniasis, since infection in dogs generally precedes the appearance of human cases.INTRODUÇÃO: Diversos estudos avaliaram fatores de risco para leishmaniose visceral humana, mas poucos focalizaram a infecção canina. O objetivo deste estudo é avaliar a associação entre condições sócio-ambientais peridomiciliares e a presença de cães sorologicamente positivos para Leishmania chagasi em Teresina, Brasil. MÉTODOS: Estudo caso-controle baseado nos resultados de

Using Proteomics to Understand How Leishmania Parasites Survive inside the Host and Establish Infection.

Science.gov (United States)

Veras, Patrícia Sampaio Tavares; Bezerra de Menezes, Juliana Perrone

2016-08-19

Leishmania is a protozoan parasite that causes a wide range of different clinical manifestations in mammalian hosts. It is a major public health risk on different continents and represents one of the most important neglected diseases. Due to the high toxicity of the drugs currently used, and in the light of increasing drug resistance, there is a critical need to develop new drugs and vaccines to control Leishmania infection. Over the past few years, proteomics has become an important tool to understand the underlying biology of Leishmania parasites and host interaction. The large-scale study of proteins, both in parasites and within the host in response to infection, can accelerate the discovery of new therapeutic targets. By studying the proteomes of host cells and tissues infected with Leishmania, as well as changes in protein profiles among promastigotes and amastigotes, scientists hope to better understand the biology involved in the parasite survival and the host-parasite interaction. This review demonstrates the feasibility of proteomics as an approach to identify new proteins involved in Leishmania differentiation and intracellular survival.

Actividad contra Leishmania sp. (Kinetoplastida: Trypanosomatidae de plantas en una Reserva Biológica de Costa Rica

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Misael Chinchilla-Carmona

2014-09-01

Full Text Available La leishmaniosis es una enfermedad muy importante para el ser humano pero su tratamiento es bastante difícil. Por esta razón muchos investigadores han venido buscando plantas que contengan componentes químicos activos contra esta parasitosis. En Costa Rica no se tienen estudios al respecto y por eso el objetivo de este estudio fue la búsqueda de componentes activos contra Leishmania sp. en plantas de Costa Rica; 67 especies de la Reserva Biológica Alberto Manuel Brenes (REBAMB fueron seleccionadas para realizar este trabajo. Para ello se prepararon extractos crudos hidro-alcohólicos de material fresco o desecado de raíz, tallo, hojas maduras o tiernas, flores y frutos inmaduros o maduros. Usando pruebas presuntivas y luego específicas, se analizó el efecto de tales extractos sobre una cepa de Leishmania (OCR. Se consideraron plantas promisorias solamente aquellas en que al menos una de sus partes presentara un CI50<100µg/mL. Las plantas seleccionadas fueron: Bocconia frutescens, Clematis dioica,Cordia megalantha, Eugenia austin-smithii, Guarea bullata, Guateria tonduzii, Mikania holwayana, Nectandra membranacea,Neurolaena lobata, Persea povedae, Piper auritum, Rollinia pittieri, Solanum arboreum, Tetrorchidium euryphyllum, Witheringia solanacea y Zanthoxylum juniperinum. Existió una ligera tendencia de positividad mayor para los extractos frescos y la actividad se presentó en una y hasta más de cuatro partes de la planta. La mayoría de los extractos activos no fueron tóxicos. Se discute la importancia de estos nuevos hallazgos, en relación con el nuevo conocimiento científico y su proyección en el tratamiento de la leishmaniosis.

Molecular Characterization of Leishmania Species Isolated from Cutaneous Leishmaniasis in Yemen

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Mahdy, Mohammed A. K.; Al-Mekhlafi, Hesham M.; Al-Mekhlafi, Abdulsalam M.; Lim, Yvonne A. L.; Bin Shuaib, Naemah O. M.; Azazy, Ahmed A.; Mahmud, Rohela

2010-01-01

Background Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in the tropics and subtropics with a global yearly incidence of 1.5 million. Although CL is the most common form of leishmaniasis, which is responsible for 60% of DALYs lost due to tropical-cluster diseases prevalent in Yemen, available information is very limited. Methodology/Principal Findings This study was conducted to determine the molecular characterization of Leishmania species isolated from human cutaneous lesions in Yemen. Dermal scrapes were collected and examined for Leishmania amastigotes using the Giemsa staining technique. Amplification of the ribosomal internal transcribed spacer 1(ITS-1) gene was carried out using nested PCR and subsequent sequencing. The sequences from Leishmania isolates were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods. The trees identified Leishmania tropica from 16 isolates which were represented by two sequence types. Conclusions/Significance The predominance of the anthroponotic species (i.e. L. tropica) indicates the probability of anthroponotic transmission of cutaneous leishmaniasis in Yemen. These findings will help public health authorities to build an effective control strategy taking into consideration person–to-person transmission as the main dynamic of transmission of CL. PMID:20862227

Leishmaniasis in Turkey: Visceral and cutaneous leishmaniasis caused by Leishmania donovani in Turkey

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Özbilgin, Ahmet; Harman, Mehmet; Karakuş, Mehmet; Bart, Aldert; Töz, Seray; Kurt, Özgür; Çavuş, İbrahim; Polat, Erdal; Gündüz, Cumhur; van Gool, Tom; Özbel, Yusuf

2017-01-01

In Turkey, the main causative agents are Leishmania tropica (L. tropica) and Leishmania infantum (L. infantum) for cutaneous leishmaniasis (CL) and L. infantum for visceral leishmaniasis (VL). In this study, we investigated leishmaniasis cases caused by L. donovani and established animal models for

Curcumin overcomes the inhibitory effect of nitric oxide on Leishmania.

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Chan, Marion Man-Ying; Adapala, Naga Suresh; Fong, Dunne

2005-04-01

Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.

The current status of phlebotomine sandflies (Diptera: Psychodidae) in Tunisia and their role on Leishmania transmission: A review

OpenAIRE

Ahmed Tabbabi; Sajida Sboui; Jabeur Daaboub

2017-01-01

In Tunisia, the epidemiological situation of leishmaniasis is characterized by the coexistence in a rather circumscribed territory (165000 km2, including the Sahara) of 4 forms of leishmaniasis caused by 3 species: Leishmania infantum, Leishmania major and Leishmania tropica (L. tropica) (synonymous Leishmania killicki). One of the factors determining the clinical, epidemiological and immunological diversity of leishmanioses is certainly the existence of a vector-parasite specificity of of...

Soil contamination by Toxocara spp. eggs in a rural community from Mirante do Paranapanema, São Paulo State, BrazilContaminação do solo por ovos de Toxocara spp. em assentamento rural de Mirante do Paranapanema, São Paulo, Brasil

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Mariele Catherine Alves Silva

2012-08-01

Full Text Available Toxocariasis is a zoonosis caused by Toxocara canis and T. cati. The mematoda infect dogs and cats, respectively. Human become infected particularly by accidental ingestion of larvated eggs present in the soil. The disease has a cosmopolitan distribution, but it is more frequent in disadvantaged populations. The aim of this study was to evaluate the environmental contamination by Toxocara spp. eggs in a rural community from the Mirante do Paranapanema, State of São Paulo, Brazil. Soil samples from 31 out of 105 plots were collected in eight different places on each house. The samples were submitted to flotation technique in zinc sulphate solution (d=1.20 g/cm3. Eggs of Toxocara spp. were recovered in 12 (38.7% out of the 31 plots. At least one dog was registered in 26 (83.87% of the 31 plots examined and at least one cat in 21 (67.74%. In 15 (48.38% plots, the presence of both dogs and cats was observed, but no relation between the presence of pets in the plots and soil contamination (p=1.0; Odds Ratio= 0.611; CI 95%= 0.03457-10.802. However the environmental contamination by Toxocara spp. eggs associated to the poor conditions of the inhabitants can be an important risk factor for the human population to ocular or visceral larva migrans.A toxocaríase é uma zoonose ocasionada pelos nematódeos Toxocara canis e T. cati, que infectam, respectivamente, cães e gatos. A infecção humana é ocasionada principalmente pela ingestão acidental de ovos larvados presentes no solo. A doença é de caráter cosmopolita, mas ocorre com maior freqüência em populações de fragilidade social. O objetivo deste estudo foi avaliar a contaminação de solo por ovos de Toxocara spp. em um assentamento rural no município de Mirante do Paranapanema, São Paulo. Amostras (n=31 de 100 gramas de solo foram colhidas de oito pontos diferentes de cada lote, ao redor da residência, sendo duas na face frontal, duas nas respectivas laterais e duas nos fundos

Application of the microscopic method in cutaneous leishmania diagnosis

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Mohammed Wael Daboul

2011-10-01

Full Text Available Introduction: Cutaneous leishmania is spreading fast. This study aims at developing the microscopic method to achieve a full detection of all positive cases of leishmania.Methods: 50 human cases have been studied by applying microscopic smears stained with Wright stain. Microscopic photos were taken for the presumed unfamiliar figures.Results: Mononuclear cells with tails are present at a rate of (98%. They are associated with Leishman Donovan (LD bodies in 50% of the cases. The polygonal figures and the spherical forms are present at the same rate (60% and are associated with LD bodies in 24% of the cases. The small promastigote like forms are seen at a rate of (76% and are associated with LD bodies in 26% of the cases. The giant promastigotes like forms are present in (80% of the cases and are associated with LD bodies in 28% of the cases. Candle flame forms are present in (40% of the cases and are associated with the LD bodies in 21% of the cases.Discussion: It is applicable to use those discovered figures in diagnosing cutaneous leishmania.

Phototoxic effects of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) on the viability of Leishmania major and Leishmania braziliensis promastigotes

Science.gov (United States)

Guerra Pinto, Juliana; Ferreira-Strixino, Juliana; Mittmann, Josane

2016-06-01

American cutaneous leishmaniasis (ACL) is an infectious disease caused by protozoans of the genus Leishmania. The treatment may consist of pentavalent antimonials or pentamidine and amphotericin. However, these treatments are extremely aggressive. Photodynamic antimicrobial chemotherapy (PACT) involves the same mechanism of photodynamic therapy which associates a photosensitizer with oxygen and a light source generating a photochemical reaction leading to cell death. The aim of this study was to verify the potential use of silicon bis (dimetilaminoetanoxi)-phthalocyanine (SiPc) compound in photodynamic treatment through evaluation of its phototoxic effect in promastigotes of the genus Leishmania braziliensis and Leishmania major. Treatment with SiPc was able to drastically affect the viability of the parasites as well as affect their growth and morphology, after PACT treatment. The data shown in this study allows us to conclude that SiPc is a promising photosensitizer (PS) since it does not affect parasite growth and viability in the dark. After PACT with this phthalocyanine, over 99% of parasites were killed with the higher concentration and a light dose used. These results suggest that SiPc can be used in future to treat CL, however, further studies are necessary to determine whether the PS are toxic to mononuclear phagocytic cells and epithelial cells which will also be affected by therapy when applied topically.

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

Science.gov (United States)

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

2015-01-01

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

Endocarditis bacteriana por Kocuria kristinae en paciente inmunocompetente. Reporte de un caso

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Alirio R. Bastidas, MD

2013-09-01

Full Text Available Las infecciones por microorganismos del género Kocuria spp. han sido descritas con mayor frecuencia en pacientes con enfermedades crónicas y estados de inmunosupresión. Comúnmente, no se ha reportado su aislamiento como causa de endocarditis en pacientes jóvenes e inmunocompetentes. Se deben diferenciar de las infecciones producidas por Staphylococcus spp. ya que su evolución clínica puede ser similar y sólo el aislamiento y tipificación en cultivos permite hacer el diagnóstico etiológico definitivo y dirigir la terapia antibiótica adecuada. Se describe el caso de un paciente joven e inmunocompetente que cursó con endocarditis bacteriana, aislándose Kocuria kristinae en hemocultivos.

Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition.

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Daniel P Depledge

2010-09-01

Full Text Available A family of hydrophilic acylated surface (HASP proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic and intracellular (amastigote stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia have lost HASP genes from their genomes.We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia species, L. (V. braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L. mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o HASPs are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family.These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are

Effect of Kelussia odoratissima Mozaff essential oil on promastigot form of Leishmania major (in vitro)

OpenAIRE

Pirali Kheirabadi Khodadad; Saei Dehkordi Siavash; Kheibari Parviz

2015-01-01

Introduction: Leishmaniasis is a zoonotic disease caused by a protozoan of the genus Leishmania. In this study, the effects of Kelussia odoratissima Mozaff essential oil on the promastigot form of Leishmania major were studied. Methods: In this study, the effects of Kelussia odoratissima Mozaff essential oil on the promastigot form of Leishmania major were assessed by calculating the average number of surviving promastigots after exposure to different concentrations of essential oil, relativ...

Sand fly-Leishmania interactions: long relationships are not necessarily easy

OpenAIRE

Ramalho-Ortigao, Marcelo; Saraiva, Elvira M.; Traub-Csekö, Yara M.

2010-01-01

Sand fly and Leishmania are one of the best studied vector-parasite models. Much is known about the development of these parasites within the sand fly, and how transmission to a suitable vertebrate host takes place. Various molecules secreted by the vector assist the establishment of the infection in a vertebrate, and changes to the vector are promoted by the parasites in order to facilitate or enhance transmission. Despite a generally accepted view that sand flies and Leishmania are also one...

Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection.

Science.gov (United States)

Glennie, Nelson D; Yeramilli, Venkata A; Beiting, Daniel P; Volk, Susan W; Weaver, Casey T; Scott, Phillip

2015-08-24

Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. © 2015 Glennie et al.

The development of Leishmania turanica in sand flies and competition with L. major.

Science.gov (United States)

Chajbullinova, Alsu; Votypka, Jan; Sadlova, Jovana; Kvapilova, Katerina; Seblova, Veronika; Kreisinger, Jakub; Jirku, Milan; Sanjoba, Chizu; Gantuya, Sambuu; Matsumoto, Yoshitsugu; Volf, Petr

2012-10-02

In Central Asian foci of zoonotic cutaneous leishmaniases, mixed infections of Leishmania turanica and L. major have been found in a reservoir host (the great gerbil, Rhombomys opimus) as well as in the sand fly vector Phlebotomus papatasi, but hybrids between these two Leishmania species have never been reported. In addition, the role of sand fly species other than P. papatasi in L. turanica circulation is not clear. In this work we compared the development of L. turanica in three sand fly species belonging to different subgenera. In addition, we studied experimental co-infections of sand flies by both Leishmania species using GFP transfected L. turanica (MRHO/MN/08/BZ18(GFP+)) and RFP transfected L. major (WHOM/IR/-/173-DsRED(RFP+)). The possibility of Leishmania genetic exchange during the vectorial part of the life cycle was studied using flow cytometry combined with immunofluorescent microscopy. Late-stage infections of L. turanica with frequent colonization of the stomodeal valve were observed in the specific vector P. (Phlebotomus) papatasi and in the permissive vector P. (Adlerius) arabicus. On the other hand, in P. sergenti (the specific vector of L. tropica), L. turanica promatigotes were present only until the defecation of bloodmeal remnants. In their natural vector P. papatasi, L. turanica and L. major developed similarly, and the spatiotemporal dynamics of localization in the sand fly gut was the same for both leishmania species. Fluorescence microscopy in combination with FACS analyses did not detect any L. major / L. turanica hybrids in the experimental co-infection of P. papatasi and P. duboscqi. Our data provide new insight into the development of different leishmania parasite species during a mixed infection in the sand fly gut. Despite the fact that both Leishmania species developed well in P. papatasi and P. duboscqi and did not outcompete each other, no genetic exchange was found. However, the ability of L. turanica to establish late

Uji Infeksi Mycosphaerella spp Terhadap Bibit Eucalyptus spp

OpenAIRE

Lidya Morita Sondang

2009-01-01

Tujuan penelitian ini adalah untuk mengetahui tingkat ketahanan 2 klon Eucalyptus spp yaitu Eucalyptus grandis x Eucalyptus pellita dan Eucalyptus grandis x Eucalyptus urophylla terhadap Mycosphaerella spp serta mengetahui virulensi Mycospaherella spp pada 2 kelas umur (2 dan 3 bulan) pada tanaman Eucalyptus spp. Penelitian ini dilaksanakan dengan pengambilan sampel bibit tanaman Eucalyptus grandis x Eucalyptus pellita dan Eucalyptus grandis x Eucalyptus urophylla dari pembibitan PT.Toba Pulp...

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

Science.gov (United States)

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

2017-11-01

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

Leishmania chagasi/infantum : further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America

NARCIS (Netherlands)

Campos Ponce, M.; Ponce, C.; Ponce, E; Maingon, R.D.

2005-01-01

In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran

Leishmania chagasi/infantum: further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America.

NARCIS (Netherlands)

Campos Ponce, M.; Ponce, C.; Ponce, E.; Maingon, R.D.

2005-01-01

In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran

Discovery of inhibitors of Leishmania β-1,2-mannosyltransferases using a click-chemistry-derived guanosine monophosphate library.

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Phillip van der Peet

Full Text Available Leishmania spp. are a medically important group of protozoan parasites that synthesize a novel intracellular carbohydrate reserve polymer termed mannogen. Mannogen is a soluble homopolymer of β-1,2-linked mannose residues that accumulates in the major pathogenic stages in the sandfly vector and mammalian host. While several steps in mannogen biosynthesis have been defined, none of the enzymes have been isolated or characterized. We report the development of a simple assay for the GDP-mannose-dependent β-1,2-mannosyltransferases involved in mannogen synthesis. This assay utilizes octyl α-D-mannopyranoside to prime the formation of short mannogen oligomers up to 5 mannose residues. This assay was used to screen a focussed library of 44 GMP-triazole adducts for inhibitors. Several compounds provided effective inhibition of mannogen β-1,2-mannosyltransferases in a cell-free membrane preparation. This assay and inhibitor compounds will be useful for dissecting the role of different mannosyltransferases in regulating de novo biosynthesis and elongation reactions in mannogen metabolism.

Phlebotomine sandflies (Diptera, Phlebotomidae) of Lanzarote Island (Canary Islands, Spain): Ecological survey and evaluation of the risk of Leishmania transmission.

Science.gov (United States)

Morillas-Márquez, Francisco; Díaz-Sáez, Victoriano; Morillas-Mancilla, María Jesús; Corpas-López, Victoriano; Merino-Espinosa, Gemma; Gijón-Robles, Patricia; Martín-Sánchez, Joaquina

2017-04-01

Phlebotomine sandflies are natural vectors of Leishmania spp. and their expansion throughout has been evidenced in the last few years due to the global warming and changes in human behavior, worsening leishmaniasis problem. However, phlebotomine sandflies have been captured in small numbers on the Canary Islands, particularly on the island of Lanzarote, where only one limited survey was carried out almost thirty years ago. The proximity of this island to Morocco, in addition to the high number of tourists, sometimes accompanied by their dogs, from leishmaniasis endemic regions, highlights the importance of studying the sandfly fauna on this island in order to determine the transmission risk of leishmaniasis Thirty-eight sampling sites spread across the island were studied, and ecological features were gathered to identify the ecological traits associated to the presence of sandflies. Only 85 sandfly specimens were captured (1.18/m 2 ) with the following species distribution: Sergentomyia minuta (0.15 specimens/m 2 ), which was reported for the first time on this island, and S. fallax (1.03/m 2 ). Sandfly captured were achieved in only 7 out of 38 stations. No specimen of the Phlebotomus genus was captured and given that none of the species captured has been demonstrated vectors of human pathogenic Leishmania and considering that they were captured in low frequency and density, it can be concluded that the current leishmaniasis transmission risk is null. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in Macrophage Gene Expression Associated with Leishmania (Viannia braziliensis Infection.

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Clemencia Ovalle-Bracho

Full Text Available Different Leishmania species cause distinct clinical manifestations of the infectious disease leishmaniasis. It is fundamentally important to understand the mechanisms governing the interaction between Leishmania and its host cell. Little is known about this interaction between Leishmania (Viannia braziliensis and human macrophages. In this study, we aimed to identify differential gene expression between non-infected and L. (V braziliensis-infected U937-derived macrophages. We deployed a whole human transcriptome microarray analysis using 72 hours post-infection samples and compared those samples with their non-infected counterparts. We found that 218 genes were differentially expressed between infected and non-infected macrophages. A total of 71.6% of these genes were down-regulated in the infected macrophages. Functional enrichment analyses identified the steroid and sterol/cholesterol biosynthetic processes between regulatory networks down-regulated in infected macrophages. RT-qPCR further confirmed this down-regulation in genes belonging to these pathways. These findings contrast with those from studies involving other Leishmania species at earlier infection stages, where gene up-regulation for this metabolic pathway has been reported. Sterol biosynthesis could be an important biological process associated with the expression profile of macrophages infected by L. (V. braziliensis. Differential transcriptional results suggest a negative regulation of the genetic regulatory network involved in cholesterol biosynthesis.

Impact of Leishmania mexicana infection on dendritic cell signaling and functions.

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Irazú Contreras

2014-09-01

Full Text Available Leishmania parasites have the ability to modify macrophage signaling pathways in order to survive and multiply within its mammalian host. They are also known to invade other cells including neutrophils, fibroblasts and dendritic cells (DCs. DCs have an important role in immunity as the link between innate and adaptive immunity, necessary for the development of an effective response; however, the impact of Leishmania mexicana infection on DCs has been poorly studied. Herein, we report that Leishmania infection rapidly induced DC protein tyrosine phosphatases activity, leading to MAP kinases inactivation. In line with this, L. mexicana was found to decrease the nuclear translocation of transcription factors such as AP-1 and NF-κB. Concomitantly, L. mexicana-infected DCs showed reduced expression of several surface antigen-presenting and co-stimulatory molecules upon LPS stimulation. Leishmania-induced interference on DC maturation was further reflected by their reduced capacity to present OVA antigen to OVA-specific T cells, as shown by abrogation of IL-2 production by the T cells. Collectively, our data revealed that DC infection by L. mexicana appears to affect the cellular and immunological mechanisms necessary for the development of an effective and protective immune response, therefore favouring the survival and propagation of the parasite within its host.

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

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Flávio França

1993-09-01

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

First evidence of intraclonal genetic exchange in trypanosomatids using two Leishmania infantum fluorescent transgenic clones.

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Estefanía Calvo-Álvarez

2014-09-01

Full Text Available The mode of reproduction in Leishmania spp has been argued to be essentially clonal. However, recent data (genetic analysis of populations and co-infections in sand flies have proposed the existence of a non-obligate sexual cycle in the extracellular stage of the parasite within the sand fly vector. In this article we propose the existence of intraclonal genetic exchange in the natural vector of Leishmania infantum.We have developed transgenic L. infantum lines expressing drug resistance markers linked to green and red fluorescent reporters. We hypothesized whether those cells with identical genotype can recognize each other and mate. Both types of markers were successfully exchanged within the sand fly midgut of the natural vector Phlebotomus perniciosus when individuals from these species were fed with a mixture of parental clones. Using the yellow phenotype and drug resistance markers, we provide evidence for genetic exchange in L. infantum. The hybrid progeny appeared to be triploid based on DNA content analysis. The hybrid clone analyzed was stable throughout the complete parasite life cycle. The progress of infections by the hybrid clone in BALB/c mice caused a reduction in parasite loads in both spleen and liver, and provided weight values similar to those obtained with uninfected mice. Spleen arginase activity was also significantly reduced relative to parental strains.A L. infantum hybrid lineage was obtained from intraclonal genetic exchange within the midgut of the natural vector, suggesting the ability of this parasite to recognize the same genotype and mate. The yellow hybrid progeny is stable throughout the whole parasite life cycle but with a slower virulence, which correlates well with the lower arginase activity detected both in vitro and in vivo infections.

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

Science.gov (United States)

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

2018-01-01

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

Antileishmanial activity of licochalcone A in mice infected with Leishmania major and in hamsters infected with Leishmania donovani

DEFF Research Database (Denmark)

Chen, M; Christensen, S B; Theander, T G

1994-01-01

This study was designed to examine the antileishmanial activity of the oxygenated chalcone licochalcone A in mice and hamsters infected with Leishmania parasites. Intraperitoneal administration of licochalcone A at doses of 2.5 and 5 mg/kg of body weight per day completely prevented lesion...... development in BALB/c mice infected with Leishmania major. Treatment of hamsters infected with L. donovani with intraperitoneal administration of licochalcone A at a dose of 20 mg/kg of body weight per day for 6 consecutive days resulted in a > 96% reduction of parasite load in the liver and the spleen...... consecutive days resulted in > 65 and 85% reductions of L. donovani parasite loads in the liver and the spleen, respectively, compared with those of untreated control hamsters. These data clearly demonstrate that licochalcone A is a promising lead for the development of a new drug against leishmaniases....

Characterization of monomeric DNA-binding protein Histone H1 in Leishmania braziliensis.

Science.gov (United States)

Carmelo, Emma; González, Gloria; Cruz, Teresa; Osuna, Antonio; Hernández, Mariano; Valladares, Basilio

2011-08-01

Histone H1 in Leishmania presents relevant differences compared to higher eukaryote counterparts, such as the lack of a DNA-binding central globular domain. Despite that, it is apparently fully functional since its differential expression levels have been related to changes in chromatin condensation and infectivity, among other features. The localization and the aggregation state of L. braziliensis H1 has been determined by immunolocalization, mass spectrometry, cross-linking and electrophoretic mobility shift assays. Analysis of H1 sequences from the Leishmania Genome Database revealed that our protein is included in a very divergent group of histones H1 that is present only in L. braziliensis. An antibody raised against recombinant L. braziliensis H1 recognized specifically that protein by immunoblot in L. braziliensis extracts, but not in other Leishmania species, a consequence of the sequence divergences observed among Leishmania species. Mass spectrometry analysis and in vitro DNA-binding experiments have also proven that L. braziliensis H1 is monomeric in solution, but oligomerizes upon binding to DNA. Finally, despite the lack of a globular domain, L. braziliensis H1 is able to form complexes with DNA in vitro, with higher affinity for supercoiled compared to linear DNA.

Serological and molecular survey of Leishmania infection in dogs from Luanda, Angola.

Science.gov (United States)

Vilhena, Hugo; Granada, Sara; Oliveira, Ana Cristina; Schallig, Henk D F H; Nachum-Biala, Yaarit; Cardoso, Luís; Baneth, Gad

2014-03-24

Canine leishmaniosis (CanL) due to Leishmania infantum is a global zoonosis endemic in more than 70 countries in Europe, North Africa, Asia and America; however, data on this infection is scarce from southern Africa. The aim of this study was to survey dogs in Luanda, Angola, for Leishmania infection. One hundred-and-three dogs presented to a veterinary medical centre in Luanda were serologically and molecularly assessed for Leishmania with the direct agglutination test (DAT) and polymerase chain reaction (PCR). Two dogs were seropositive, with DAT titres of 800 and ≥6400; the latter was also found to be PCR-positive and confirmed to be infected with L. infantum by DNA sequence analysis. No other dog was found to be PCR-positive. The first dog had been imported from Portugal, but the latter had never left Angola (neither had its parents), strongly suggesting an autochthonous infection. Although other cases of CanL have previously been described in the country, this is the first reported study of canine Leishmania infection at the population level, as well as the first report on the molecular characterization of L. infantum in dogs from Angola.

Occurrence of Campylobacter spp. and Cryptosporidium spp. in seagulls (Larus spp.).

Science.gov (United States)

Moore, John E; Gilpin, Deidre; Crothers, Elizabeth; Canney, Anne; Kaneko, Aki; Matsuda, Motoo

2002-01-01

An investigation was carried out into the prevalence of thermophilic Campylobacter subspecies (spp.) and Cryptosporidium spp. in fresh fecal specimens collected from members of the gull family (Larus spp.) from three coastal locations of Northern Ireland. A total of 205 fresh fecal specimens were collected from gulls, of which 28 of 205 (13.7%) were positive for Campylobacter spp. and none of 205 for Cryptosporidium spp. Of these campylobacters, 21 of 28 (75%) isolates obtained belonged to the urease-positive thermophilic Campylobacter (UPTC) taxon, followed by five of 28 (17.9%) Campylobacter lari and 2/28 (7.1%) Campylobacter jejuni. It is significant that seagulls are the sole warm-blooded animal host of this bacterial taxon in Northern Ireland. It is proposed that physiological adaptation to starvation by gulls may lead to increased concentrations of urea through energy production from protein, yielding increased levels of urea for metabolism by UPTC organisms. In general, the possibility exists that environmental contamination of surface waters with campylobacters might be mediated by wild birds (such as gulls), where such waters are used for recreational purposes or where such waters are consumed untreated, might represent a risk to public health.

Estudo genômico do nível de infecção por Babesia bovis em bovinos da raça angus

OpenAIRE

Santana, Clarissa Helena [UNESP

2016-01-01

A bovinocultura é um setor com importante destaque no agronegócio brasileiro. O carrapato Ripicephalus (Boophilus) microplus é responsável por perdas econômicas significativas aos pecuaristas e é vetor de hemoparasitoses como Anaplasma spp e Babesia spp. Sabe-se que os bovinos Bos taurus taurus são mais susceptíveis à infestação por carrapatos do que Bos taurus indicus. Acredita-se que o mesmo ocorra para a infecção por Babesia bovis. Neste trabalho, foram avaliados, em duas colheitas, 355 bo...

Vigilancia en red de los serotipos y la susceptibilidad antimicrobiana de Salmonella spp., Shigella spp. Y Vibrio cholerae O1, 1997 - 1999

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Nélida Muñoz

2000-09-01

Full Text Available En 1997, el Grupo de Microbiología del INS estableció un programa en red con los Laboratorios de Salud Pública (LSP del país y el apoyo de la OPS, para la vigilancia de los principales patógenos causantes de enfermedad diarreica aguda. El objetivo fue conocer los serotipos y los patrones de resistencia antimicrobiana de Salmonella spp., Shigella spp. y Vibrio cholerae O1. Los aislamientos fueron confirmados de acuerdo con los esquemas de identificación bioquímica y serológica estandarizados y la determinación de la susceptibilidad antimicrobiana se realizó por la técnica de difusión de disco (Kirby-Bauer. De 1997 a 1999, participaron 22 LSP con el envio de 976 aislamientos, 96% de origen clínico y 4% de alimentos; 34% Salmonella spp., 23% Shigella spp. y 42% V. cholerae 01. La distribución por serotipo de Salmonella fue 39% S. Enteritidis, 27% S. Typhimurium, 9% grupo El, 5% S. Typhi y 20% otros serotipos; de los aislamientos de Shigella, 67% fueron S. grupo flexneriza, 30% S sonnei, 2% S. dysenteriae y 1% S. boydii. Para V. cholerae 01, 99% fue serotipo Ogawa. La susceptibilidad antimicrobiana determinó que 56% de los aislamientos de Salmonella eran resistentes y 22% multirresistentes, con un patrón predominante de ampicilina, tetraciclina y trimetoprim-sulfa (SXT. De los aislamientos de Shigella, 97% fueron resistentes y 57% multirresistentes, con un patrón de ampicilina, tetraciclina, cloranfenicol y SXT. No se observaron cambios en la susceptibilidad de V. cholerae O1. Este estudio enfatiza la importancia de continuar con el programa de vigilancia, para conocer la epidemiologia de la EDA en Colombia, darle un tratamiento óptimo a estas infecciones y poder diseñar programas para disminuir la diseminación de bacterias resistentes.

Endocarditis bacteriana por Kocuria kristinae en paciente inmunocompetente: Reporte de un caso

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Alirio R Bastidas

2013-09-01

Full Text Available Las infecciones por microorganismos del género Kocuria spp. han sido descritas con mayor frecuencia en pacientes con enfermedades crónicas y estados de inmunosupresión. Comúnmente, no se ha reportado su aislamiento como causa de endocarditis en pacientes jóvenes e inmunocompetentes. Se deben diferenciar de las infecciones producidas por Staphylococcus spp. ya que su evolución clínica puede ser similar y sólo el aislamiento y tipifi cación en cultivos permite hacer el diagnóstico etiológico defi nitivo y dirigir la terapia antibiótica adecuada. Se describe el caso de un paciente joven e inmunocompetente que cursó con endocarditis bacteriana, aislándose Kocuria kristinae en hemocultivos.

An agent-based model for Leishmania major infection

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

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

Detection of Leishmania parasites in the blood of patients with isolated cutaneous leishmaniasis.

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Nakkash-Chmaisse, Hania; Makki, Raja; Nahhas, Georges; Knio, Khouzama; Nuwayri-Salti, Nuha

2011-07-01

The consequences of the spread of Leishmania parasites to the blood from lesions in patients with cutaneous leishmaniasis are numerous. To assess the magnitude of this invasion we conducted the present study on patients referred to the American University of Beirut Medical Center for cutaneous leishmaniasis. Patients referred for the management of cutaneous leishmaniasis were included in the study. Skin and blood cultures for Leishmania were taken from these patients. One hundred sixty-two patients were proven to have cutaneous leishmaniasis by pathology; 52% were males and 44% females (gender information was missing for 4%). Patient age ranged from 5 months to 70 years. None of the patients had received treatment for Leishmania. We obtained parasite isolates from 85 patients (52.5%), proven by cultures from skin and blood/blood components. Interestingly, the parasite was isolated in the blood and blood components of 50 patients (30.9%). Isoenzyme analysis confirmed the fact that the organisms in blood and skin were the same; from the 28 isolates that were positive in both skin and blood, eight isolates were Leishmania major and two were Leishmania tropica. The remaining isolates, whether positive in both blood and skin or in either of these tissues, skin or blood and its products, were Leishmania infantum sensu lato. In the current study, the detection rate of parasites in the blood of patients with cutaneous leishmaniasis was high. This illustrates the invasive characteristic of the parasite that has escaped the skin. Testing should be considered in areas other than Lebanon, especially around the Mediterranean basin. Whether these findings support the administration of systemic treatment for cutaneous leishmaniasis or not needs to be confirmed in larger prospective studies. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Leprosy Associated with Atypical Cutaneous Leishmaniasis in Nicaragua and Honduras.

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Soto, Lucrecia Acosta; Caballero, Nelson; Fuentes, Lesny Ruth; Muñoz, Pedro Torres; Gómez Echevarría, Jose Ramón; López, Montserrat Pérez; Bornay Llinares, Fernando Jorge; Stanford, John L; Stanford, Cynthia A; Donoghue, Helen D

2017-10-01

In Central America, few cases of leprosy have been reported, but the disease may be unrecognized. Diagnosis is based on clinical criteria and histology. Preliminary field work in Nicaragua and Honduras found patients, including many children, with skin lesions clinically suggestive of atypical cutaneous leishmaniasis or indeterminate leprosy. Histology could not distinguish these diseases although acid-fast organisms were visible in a few biopsies. Lesions healed after standard antimicrobial therapy for leprosy. In the present study, patients, family members, and other community members were skin-tested and provided nasal swabs and blood samples. Biopsies were taken from a subgroup of patients with clinical signs of infection. Two laboratories analyzed samples, using local in-house techniques. Mycobacterium leprae , Leishmania spp. and Leishmania infantum were detected using polymerase chain reactions. Mycobacterium leprae DNA was detected in blood samples and nasal swabs, including some cases where leprosy was not clinically suspected. Leishmania spp. were also detected in blood and nasal swabs. Most biopsies contained Leishmania DNA and coinfection of Leishmania spp. with M. leprae occurred in 33% of cases. Mycobacterium leprae DNA was also detected and sequenced from Nicaraguan and Honduran environmental samples. In conclusion, leprosy and leishmaniasis are present in both regions, and leprosy appears to be widespread. The nature of any relationship between these two pathogens and the epidemiology of these infections need to be elucidated.

Prevalence of Hepatozoon spp. (Apicomplexa, Hepatozoidae among recently captured Brazilian snakes Prevalência de Hepatozoon spp. (Apicomplexa, Hepatozoidae em serpentes recém-capturadas no Brasil

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L.H. O'Dwyer

2003-06-01

Full Text Available The goal of this study was to determine the prevalence of Hepatozoon spp. infection in recently captured snakes from Botucatu, São Paulo State, Brazil. Blood was collected from all snakes by ventral tail venipuncture. Blood smears were air dried, fixed with methanol, and stained with 10% Giemsa solution. The slides were microscopically examined for detection of hemoparasites by light microscopy at 250x magnification. A total of 238 snakes from 23 species were examined, of which 135 (56.7% were venomous and 103 (43.3% non-venomous snakes. The more numerous venomous species sampled were Crotalus durissus terrificus (n=108 and Bothrops jararaca (n=17 and non-venomous snakes were Oxyrhopus guibei (n=35, Boa constrictor amarali (n=18, and Waglerophis merremi (n=13. Hepatozoon spp. infection was detected in 39 (16.4% snakes. The prevalence in venomous and non-venomous snakes was 20.0% and 11.7%, respectively. The highest prevalences observed were 38.9% for Boa constrictor amarali, 35.3% for Bothrops jararaca, and 19.4% for Crotalus durissus terrificus.O presente estudo teve como objetivo determinar a prevalência da infecção por Hepatozoon spp. em serpentes recém-capturadas da região de Botucatu, São Paulo. O sangue foi coletado de todas as serpentes por punção da veia caudal. Os esfregaços foram secos ao ar, fixados com metanol e corados com solução de Giemsa a 10%. Examinaram-se 238 serpentes pertencentes a 23 espécies, das quais 135 (56,7% eram venenosas e 103 (43,3% não venenosas. As espécies venenosas mais representativas foram Crotalus durissus terrificus (n=108 e Bothrops jararaca (n=17 e as não venenosas foram Oxyrhopus guibei (n=35, Boa constrictor amarali (n=18 e Waglerophis merremi (n=13. A infecção por Hepatozoon spp. foi detectada em 39 (16,4% serpentes. As prevalências em serpentes venenosas e não venenosas foram 20,0% e 11,7%, respectivamente. As maiores prevalências foram 38,9% para Boa constrictor amarali, 35

Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

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Marie Samanovic

2009-01-01

Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

High frequency of visceral leishmaniasis in dogs under veterinary clinical care in an intense transmission area in the state of Tocantins, Brazil

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Santos, Helcileia Dias; Galvão, Samara Rocha; Dias, Francisca Elda Ferreira; Ribeiro, Taiã Mairon Peixoto; Negreiros Filho, Osmar; Sousa, Sebastiana Adriana Pereira; Minharro, Silvia

2017-01-01

ABSTRACT: A direct search for parasites were used as the diagnostic test to determine the frequency of Leishmania spp. infection in dogs ( Canis lupus familiaris ) under veterinary clinical care in the city of Araguaína, Tocantins, Brazil. For this approach, lymph node cell samples were collected using needle aspiration from 649 dogs of different breeds and ages. Two hundred and sixty four (40.7%) dogs tested positive for amastigote forms of Leishmania spp. Furthermore, 202 (76.5%) dogs tha...

Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin

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Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d’ El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington LC

2015-01-01

Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55–89] μm2 for uninfected and 41 [34–51] μm2 for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm2 s−1 ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm2 s−1 ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis. PMID:26249106

Cyclic nucleotide specific phosphodiesterases of Leishmania major

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Linder Markus

2006-03-01

Full Text Available Abstract Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range