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The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model / A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Novas alternativas terapêuticas contra a leishmaniose são ainda uma prioridade. A atividade da azitromicina contra a Leishmania (Leishmania) major foi anteriormente demonstrada. Diferentes respostas entre as espécies de Leishmania fazem com que um screening de drogas específicas para espécies seja n [...] ecessário. A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis foi avaliada em Golden hamsters infectados a través de injeções de promastigotas metacíclicas e comparando com controles sem tratamento e animais tratados com antimoniato de N-metil-glucamina. Foram analisadas a espessura da pata, a cultura das lesões e disseminação para órgãos internos. A azitromicina oral em dose de 450mg/kg não teve atividade contra a infecção por Leishmania ( Leishmania) amazonensis. Para infecções devidas à Leishmania (Viannia) braziliensis, a azitromicina teve uma atividade significativa em relação aos controles sem tratamento, mas foi inferior ao antimoniato de N-metil-glucamina quanto ao controle do tamanho das lesões. Nenhuma das drogas conseguiu eliminar totalmente os parasitos das lesões. Foi concluído que a azitromicina tem atividade contra Leishmania (Viannia) braziliensis, mas não tem atividade contra Leishmania (Leishmania) amazonensis neste modelo. Abstract in english 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 agai [...] nst Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania) amazonensis. For infections due to Leishmania (Viannia) braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia) braziliensis but not against Leishmania (Leishmania) amazonensis in this model.

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

2007-12-01

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The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model / A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Novas alternativas terapêuticas contra a leishmaniose são ainda uma prioridade. A atividade da azitromicina contra a Leishmania (Leishmania) major foi anteriormente demonstrada. Diferentes respostas entre as espécies de Leishmania fazem com que um screening de drogas específicas para espécies seja n [...] ecessário. A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis foi avaliada em Golden hamsters infectados a través de injeções de promastigotas metacíclicas e comparando com controles sem tratamento e animais tratados com antimoniato de N-metil-glucamina. Foram analisadas a espessura da pata, a cultura das lesões e disseminação para órgãos internos. A azitromicina oral em dose de 450mg/kg não teve atividade contra a infecção por Leishmania ( Leishmania) amazonensis. Para infecções devidas à Leishmania (Viannia) braziliensis, a azitromicina teve uma atividade significativa em relação aos controles sem tratamento, mas foi inferior ao antimoniato de N-metil-glucamina quanto ao controle do tamanho das lesões. Nenhuma das drogas conseguiu eliminar totalmente os parasitos das lesões. Foi concluído que a azitromicina tem atividade contra Leishmania (Viannia) braziliensis, mas não tem atividade contra Leishmania (Leishmania) amazonensis neste modelo. Abstract in english 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 agai [...] nst Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania) amazonensis. For infections due to Leishmania (Viannia) braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia) braziliensis but not against Leishmania (Leishmania) amazonensis in this model.

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

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The activity of azithromycin against Leishmania (Viannia braziliensis and Leishmania (Leishmania amazonensis in the golden hamster model A atividade da azitromicina contra a Leishmania (Viannia braziliensis e a Leishmania (Leishmania amazonensis no modelo golden hamster  

Directory of Open Access Journals (Sweden)

Full Text Available 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 untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania amazonensis. For infections due to Leishmania (Viannia braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia braziliensis but not against Leishmania (Leishmania amazonensis in this model.Novas alternativas terapêuticas contra a leishmaniose são ainda uma prioridade. A atividade da azitromicina contra a Leishmania (Leishmania major foi anteriormente demonstrada. Diferentes respostas entre as espécies de Leishmania fazem com que um screening de drogas específicas para espécies seja necessário. A atividade da azitromicina contra a Leishmania (Viannia braziliensis e a Leishmania (Leishmania amazonensis foi avaliada em Golden hamsters infectados a través de injeções de promastigotas metacíclicas e comparando com controles sem tratamento e animais tratados com antimoniato de N-metil-glucamina. Foram analisadas a espessura da pata, a cultura das lesões e disseminação para órgãos internos. A azitromicina oral em dose de 450mg/kg não teve atividade contra a infecção por Leishmania ( Leishmania amazonensis. Para infecções devidas à Leishmania (Viannia braziliensis, a azitromicina teve uma atividade significativa em relação aos controles sem tratamento, mas foi inferior ao antimoniato de N-metil-glucamina quanto ao controle do tamanho das lesões. Nenhuma das drogas conseguiu eliminar totalmente os parasitos das lesões. Foi concluído que a azitromicina tem atividade contra Leishmania (Viannia braziliensis, mas não tem atividade contra Leishmania (Leishmania amazonensis neste modelo.

Ángel Sinagra

2007-12-01

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The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in the golden hamster model A atividade da azitromicina contra a Leishmania (Viannia) braziliensis e a Leishmania (Leishmania) amazonensis no modelo golden hamster  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2007-01-01

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

Directory of Open Access Journals (Sweden)

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 to Leishmania (Leishmania amazonensis are reported. In this form, less known than the diffuse one caused by the same species, the clinical manifestations are identical to those produced by other Leishmania species of the subgenus Viannia. There is, however, in the localized infection by L (L. amazonensis, a peculiar feature, only recently discovered: about 50% of the affected individuals are Montenegro-negatives. The main histologic change observed in the skin sections was the presence of groups of macrophages with a large vacuole in the cytoplasm, containing many amastigotes. The microscopic picture is similar to that found in the diffuse form of the disease, the difference being only quantitative. When in large numbers, the macrophages suffers necrosis, which generally starts at the center of the groups. First, in this process, the membrane of the parasitized cells ruptures, and the amastigotes become free; later, both cells and parasites are destroyed. The picture can be seen either in Montenegro-negative or in Montenegro-positive patients. The macrophages with amastigotes may persist in tissues for as long as 6-7 months, while in the infections due to L (V. braziliensis the parasites usually disappear in a few weeks.

Mário A. P. Moraes

1994-10-01

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

Scientific Electronic Library Online (English)

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

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

2009-08-01

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

Scientific Electronic Library Online (English)

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

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

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Leishmania mexicana amazonensis  

Science.gov (United States)

Leishmania cannot synthesize purines de novo and rely on their host to furnish these compounds. To accomplish this, they possess multiple purine nucleoside and nucleobase transporters. Subcellular fractionation, immunohistochemical localization with anti adenine nucleotide translocator (ANT) antibodies and surface biotinylation show that the mitochondrial ANT is also present in the plasma membrane of both promastigotes and amastigotes. Leishmania, however, do not appear to rely on this transporter to supplement their purine or energy requirements via preformed ATP from its host. Rather, Leishmania appear to use the plasma membrane ANT as part of a chemotaxis response. ATP is a chemorepellent for Leishmania and cells treated with atractyloside, an inhibitor of ANT, no longer exhibit negative chemotaxis for this compound. PMID:18031742

Detke, S.; Elsabrouty, R.

2008-01-01

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Ineficácia in vivo da terbinafina em leishmaniose cutânea causada por Leishmania (Leishmania) amazonensis em camundongos C57BL/6 Terbinafine in vivo inefficacy on cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis in C57BL/6 mice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Testou-se, em camundongos C57BL/6 inoculados com a cepa MHOM/BR/PH8 de Leishmania (Leishmania) amazonensis, terbinafina via oral 100mg/kg/dia, por 20 dias, solução salina 0,9% via oral como controle e stibogluconato de sódio 400mg SbV/kg/dia via subcutânea como padrão-ouro. A terbinafina mostrou-se ineficaz, clínica e parasitologicamente, e pelo ensaio por diluição limitante, quando comparada aos controles.The efficiency of terbinafine was tested in C57BL/6 mice inoculated with th...

Raimunda Nonata Ribeiro Sampaio; Gustavo Henrique Soares Takano; Ana Cristina Barbieri Malacarne; Tércio Rodrigues Pereira; Albino Verçosa Magalhães

2003-01-01

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Ineficácia in vivo da terbinafina em leishmaniose cutânea causada por Leishmania (Leishmania amazonensis em camundongos C57BL/6 Terbinafine in vivo inefficacy on cutaneous leishmaniasis caused by Leishmania (Leishmania amazonensis in C57BL/6 mice  

Directory of Open Access Journals (Sweden)

Full Text Available Testou-se, em camundongos C57BL/6 inoculados com a cepa MHOM/BR/PH8 de Leishmania (Leishmania amazonensis, terbinafina via oral 100mg/kg/dia, por 20 dias, solução salina 0,9% via oral como controle e stibogluconato de sódio 400mg SbV/kg/dia via subcutânea como padrão-ouro. A terbinafina mostrou-se ineficaz, clínica e parasitologicamente, e pelo ensaio por diluição limitante, quando comparada aos controles.The efficiency of terbinafine was tested in C57BL/6 mice inoculated with the Leishmania (Leishmania amazonensis strain MHOM/BR/PH8. The mice were administered: terbinafine at a dose of 100mg/kg/d by via oral; 0.9% saline solution orally as the control; and subcutaneous sodium stibogluconate 400mg SbV/kg/d as gold standard, for 20 days. Terbinafine was demonstrated to be ineffective when compared to the controls, using clinical and parasitological parameters and the limiting dilution assay.

Raimunda Nonata Ribeiro Sampaio

2003-07-01

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

Scientific Electronic Library Online (English)

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

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

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Role of Leishmania (Leishmania amazonensis amastigote glycosphingolipids in macrophage infectivity  

Directory of Open Access Journals (Sweden)

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

A.K. Tanaka

2007-06-01

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

Scientific Electronic Library Online (English)

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

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

2007-06-01

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Experimental treatment with sodium stibogluconate of hamsters infected with Leishmania (Leishmania chagasi and Leishmania (Leishmania amazonensis  

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Full Text Available 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.

Figueiredo Elizabeth M. de

1999-01-01

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Experimental treatment with sodium stibogluconate of hamsters infected with Leishmania (Leishmania) chagasi and Leishmania (Leishmania) amazonensis  

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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.

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

1999-01-01

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The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite  

Science.gov (United States)

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

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

2014-01-01

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

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

Fernando T. Silveira

1990-12-01

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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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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 amazone...

Figueiredo, Elizabeth M.; Silva, Jaime Costa E.; Brazil, Reginaldo P.

1999-01-01

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

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

Lourenco, Cecilia de Oliveira

2000-07-01

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Estudio del proceso de salida del parásito Leishmania amazonensis de su célula hospedera / Study of host cell egress by the parasite Leishmania amazonensis  

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Quintana Varón, María del Pilar (2010) Estudio del proceso de salida del parásito Leishmania amazonensis de su célula hospedera / Study of host cell egress by the parasite Leishmania amazonensis. Maestría thesis, Universidad Nacional de Colombia.

Quintana Varo?n, Mari?a Del Pilar

2010-01-01

 
 
 
 
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Ocorrência de leishmaniose tegumentar americana no Estado do Mato Grosso do Sul associada à infecção por Leishmania (Leishmania) amazonensis Occurrence of American tegumentary leishmaniasis in the Mato Grosso do Sul State associated to the infection for Leishmania (Leishmania) amazonensis  

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São relatados nove casos de leishmaniose tegumentar americana ocorridos no ano de 2001 em uma unidade de treinamento militar localizada no município de Bela Vista, Estado de Mato Grosso do Sul. Parasitas obtidos de lesões de seis pacientes foram isolados em cultura e posteriormente identificados através da análise de isoenzimas como sendo Leishmania (Leishmania) amazonensis. Esta é a primeira evidência da presença desta espécie de parasita em Mato Grosso do Sul.Nine cases of Amer...

Maria Elizabeth Moraes Cavalheiros Dorval; Elisa Teruya Oshiro; Elisa Cupollilo; Ana Cristina Camargo de Castro; Tulia Peixoto Alves

2006-01-01

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Ocorrência de leishmaniose tegumentar americana no Estado do Mato Grosso do Sul associada à infecção por Leishmania (Leishmania amazonensis  

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Full Text Available São relatados nove casos de leishmaniose tegumentar americana ocorridos no ano de 2001 em uma unidade de treinamento militar localizada no município de Bela Vista, Estado de Mato Grosso do Sul. Parasitas obtidos de lesões de seis pacientes foram isolados em cultura e posteriormente identificados através da análise de isoenzimas como sendo Leishmania (Leishmania amazonensis. Esta é a primeira evidência da presença desta espécie de parasita em Mato Grosso do Sul.

Dorval Maria Elizabeth Moraes Cavalheiros

2006-01-01

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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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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 ...

Dt, Wakimoto; Kv, Gaspareto; Tgv, Silveira; Mvc, Lonardoni; Sma, Aristides

2010-01-01

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Estudo comparativo entre miltefosina oral e antimoniato de N-metil glucamina parenteral no tratamento da leishmaniose experimental causada por Leishmania (Leishmania amazonensis Comparative study between oral miltefosine and parenteral N-metil glucamine antimoniate for the treatment of experimental leishmaniasis caused Leishmania (Leishmania amazonensis  

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Full Text Available Vinte e cinco camundongos infectados com Leishmania amazonensis foram tratados com antimoniato de N-metil glucamina e miltefosina oral. Critérios: medidas das patas, pesquisa de amastigotas e culturas após-tratamento. Miltefosina: 2,43mm e glucamina 3,46mm (p=0,05. Miltefosina: esfregaços e culturas negativos. Glucamina: 2 esfregaços positivos e culturas positivas (pTwenty-five mice were infected with Leishmania amazonensis and treated with glucamine and oral miltefosine. The criteria used were pad measurements and investigations of amastigotes and cultures after treatment. Measurements: miltefosine 2.43 mm and glucamine 3.46 mm (p: 0.05. Miltefosine smears and cultures were negative. Glucamine produced two positive smears and the cultures were positive (p < 0.05. Miltefosine was similar to or better than glucamine.

Arnoldo Velloso da Costa Filho

2008-08-01

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Chronic infection by Leishmania amazonensis mediated through MAPK ERK mechanisms.  

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

Martinez, Pedro A; Petersen, Christine A

2014-08-01

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Morphologic aspects of the Leishmania amazonensis submitted to ionizing radiation  

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

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Subversion and Utilization of Host Innate Defense by Leishmania amazonensis  

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Infection with Leishmania amazonensis and other members of the Leishmania mexicana complex can lead to diverse clinical manifestations, some of which are relatively difficult to control, even with standard chemotherapy. Diffuse cutaneous leishmaniasis (CL) is a rare but severe form, and its clinical hallmark is excessive parasitic growth in infected cells accompanied by profound impairments in host immune responses to the parasites. Since these parasites also cause non-healing CL in most inbr...

Soong, Lynn

2012-01-01

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Serological reactivity of different antigenic preparations of Leishmania (Leishmania) amazonensis and the Leishmania braziliensis complex / Reatividade sorológica frente a diferentes preparações antigênicas de Leishmania (Leishmania) amazonensis e do complexo Leishmania braziliensis  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Antígeno total de Leishmania (Leishmania) amazonensis e isolado do complexo Leishmania brazilienis, assim como suas respectivas frações antigênicas obtidas por cromatografia de afinidade em coluna de concanavalina-A ligada a sepharose e Jacalina ligada a agarose foram avaliadas por ensaio imunoenzim [...] ático ELISA. Para tanto, foram utilizadas amostras de soros de 229 pacientes agrupadas em leishmaniose tegumentar americana (nº=58), leishmaniose visceral (nº=28), doença de Chagas (nº=49), malaria (nº=32), tuberculose (nº=13) e voluntários saudáveis (nº=49). Houve maior reatividade das amostras de leishmaniose tegumentar americana com a utilização dos antígenos obtidos do isolado do complexo Leishmania braziliensis quando comparado com antígenos de Leishmania amazonensis (p Abstract in english Total antigen from Leishmania (Leishmania) amazonensis and isolates from the Leishmania braziliensis complex, along with their respective antigenic fractions obtained by affinity chromatography on concanavalin-A-Sepharose and jacalin-agarose columns evaluated using immunoenzymatic ELISA assay. For t [...] his, serum samples from 229 patients were used, grouped as American tegmental leishmaniasis (nº=58), visceral leishmaniasis (nº=28), Chagas disease (nº=49), malaria (nº=32), tuberculosis (nº=13) and healthy volunteers (nº=49). Samples from American tegmentary leishmaniasis showed higher reactivity with antigens isolated from the Leishmania braziliensis complex than with antigens from Leishmania amazonensis (p

Adriano, Gomes-Silva; Maria Aparecida, Souza; Sandra Regina, Afonso-Cardoso; Lívia Resende, Andrade; Reynaldo, Dietze; Elenice, Lemos; Alejandro, Belli; Silvio, Favoreto Júnior; Marcelo Simão, Ferreira.

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Effect of Glycosphingolipids Purified from Leishmania (Leishmania) amazonensis Amastigotes on Human Peripheral Lymphocytes  

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The effect of purified glycosphingolipids from Leishmania (Leishmania) amazonensis on human lymphoproliferation, on expression of human lymphocyte and monocyte markers (CD3, CD4, CD8, CD14, CD19, and CD45), and on lymphocyte protein kinase C activity was analyzed.

Giorgio, Selma; Santos, Marcia Regina M.; Straus, Anita H.; Takahashi, Helio K.; Barbie?ri, Clara Lu?cia

2003-01-01

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Ocorrência de leishmaniose tegumentar americana no Estado do Mato Grosso do Sul associada à infecção por Leishmania (Leishmania) amazonensis / Occurrence of American tegumentary leishmaniasis in the Mato Grosso do Sul State associated to the infection for Leishmania (Leishmania) amazonensis  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese São relatados nove casos de leishmaniose tegumentar americana ocorridos no ano de 2001 em uma unidade de treinamento militar localizada no município de Bela Vista, Estado de Mato Grosso do Sul. Parasitas obtidos de lesões de seis pacientes foram isolados em cultura e posteriormente identificados atr [...] avés da análise de isoenzimas como sendo Leishmania (Leishmania) amazonensis. Esta é a primeira evidência da presença desta espécie de parasita em Mato Grosso do Sul. Abstract in english Nine cases of American tegumentary leishmaniasis were reported at a Training Military Unit located in Bela Vista City, State of Mato Grosso do Sul. Parasites obtained from lesions of six patients were isolated in culture media followed by identification, through isoenzymes analysis, as being Leishma [...] nia amazonensis. This is the first evidence of the presence of the parasite in Mato Grosso do Sul.

Maria Elizabeth Moraes Cavalheiros, Dorval; Elisa Teruya, Oshiro; Elisa, Cupollilo; Ana Cristina Camargo de, Castro; Tulia Peixoto, Alves.

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Leishmaniose cutânea experimental: II - aspectos evolutivos da infecção no primata Cebus apella (Cebidae pela Leishmania (V. Braziliensis e L. (L. Amazonensis  

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Full Text Available Objetivando avaliar o potencial do primata C. apella como modelo experimental da leishmaniose cutânea, produzida pela L. (V. braziliensis e L. (L. Amazonensis , inocularam-se, via intradérmica, 3 X 10(6 de promastigotas dessas leishmanias, em 8 sítios da cauda de 10 espécimens desse primata, 5 deles com a L. (V. braziliensis e outros 5 com a L. (L. Amazonensis . Posteriormente, às inoculações, o exame semanal dos animais e biópsias mensais, revelaram os seguintes resultados relativos a cada parasita: a L. (V. braziliensis : o período de incubação foi de 15-20 dias; aos 30 dias evidenciaram-se lesões pápulo-eritematosas, que evoluíram para nódulos ao fim de 60 dias; no 3.° mês, notou-se ulceração espontânea destas lesões e, no 4° mês, deu-se o início da reparação das lesões ulceradas, culminando com a cura em um dos animais após 5 meses, em dois após 6 meses, noutro após 7 meses e, no último, após 10 meses. Quanto ao parasitismo nas lesões, foi demonstrado nos 5 animais, até 90 dias; depois disto, somente em 2 até 120 dias e, por fim, até 180 dias apenas naquele que curou depois de 10 meses, b L. (L. Amazonensis : o período de incubação foi de 20 dias; aos 30 dias notou- se lesões pápulo-eritematosas, que também evoluíram para nódulos ao fim de 60 dias, porém, a partir do 3.° mês, estas lesões regrediram rapidamente ao fim de 90 dias, quando não mais detectou-se o parasita na pele dos animais. Em relação aos testes de Montenegro, somente 2 dos 5 animais infectados com a L. (V. braziliensis reagiram ao teste, 60 e 90 dias após as inoculações. Os resultados observados permitiram confirmar a infectividade do C. apella a estas leishmanias e, também, reforçar a indicação desse primata como modelo experimental da leishmaniose cutânea causada por estes parasitas.As a means of assessing the usufulness of the monkey Cebus apella as an experimental model for the study of cutaneous leishmaniasis, 5 of these animals were inoculated intradermally at 8 sites along the tail with 3 X 106 promastigotes of L. (V. braziliensis , while a further 5 monkeys received similar inoculations with 3 X 10(6 promastigotes of L. (L. Amazonensis . Following the inoculations, weekly examinations and monthly biopsies showed evolution of resulting skin lesions to be as follows: a L. (V. braziliensis : lesions were first visible 15-20 days postinoculation (p.i, and at 30 days they were clearly of an etythematous-papular nature, which assumed a nodular form at 60 days; after 3 months a spontaneous ulceration of these lesions was noted and, at 4 months, the initiation of healing. In one animal total healing was apparent 5 months p.i; in two others at 6 months, in another monkey after 7 months, and in the last animal at 10 months p.i. Amastigotes were demonstrated in smears from the lesions of all monkeys up to 90 days p.i; up to 120 days in two animals, and at 180 days p.i. in the monkey which showed resolution of the lesions after 10 months, b L. (L. Amazonensis lesions were first apparent after 20 days p. i; at 30 days they were of an en'thematous-papular nature, developing into nodules at 60 days. From the third month of infection onwards, however, the lesions diminished rapidly and, at 90 days p.i. amastigotes were no longer detectable in the skin. With regards to the Montenegro (leishmanin skin tests, only two of the monkeys (infected with L. (V. braziliensis gave positive reactions, at 60 and 9 days p. i. These results confirm the susceptibility of C. apella to infections with both L. (V. braziliensis and L. (L. Amazonensis , and support previous indications that this monkey may serve as an useful experimental model for the study of cutaneous leishmaniasis caused by these parasites.

Fernando T. Silveira

1990-03-01

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Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis  

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

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

1999-11-01

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Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis  

Scientific Electronic Library Online (English)

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

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

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Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis  

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

Catarina AC Araujo

1999-11-01

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Studies on the effectiveness of diarylheptanoids derivatives against Leishmania amazonensis.  

Science.gov (United States)

In a previous work we demonstrated that diarylheptanoids extracted from Centrolobium sclerophyllum are very active against Leishmania amazonensis promastigotes. In order to continue our studies with these class of compounds, we decided to evaluate the activity of several diarylheptanoids derived from curcumin (diferuloyl methane) against the extracellular form (promastigotes) of L. amazonensis. Furthermore, an experiment against the intracellular form of the parasite (amastigotes) was carried out, comparing the most active compound among the curcumin derivatives (the methylcurcumin) with des-O-methylcentrolobine, the most active diarylheptanoid derived from C. sclerophyllum. PMID:10585657

Araujo, C A; Alegrio, L V; Gomes, D C; Lima, M E; Gomes-Cardoso, L; Leon, L L

1999-01-01

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Analysis and chromosomal mapping of Leishmania (Leishmania) amazonensis amastigote expressed sequence tags  

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Full Text Available SciELO Brazil | Language: English Abstract in english The characterization of expressed sequence tags (ESTs) generated from a cDNA library of Leishmania (Leishmania) amazonensis amastigotes is described. The sequencing of 93 clones generated new L. (L.) amazonensis ESTs from which 32% are not related to any other sequences in database and 68% presented [...] significant similarities to known genes. The chromosome localization of some L. (L.) amazonensis ESTs was also determined in L. (L.) amazonensis and L. (L.) major. The characterization of these ESTs is suitable for the genome physical mapping, as well as for the identification of genes encoding cysteine proteinases implicated with protective immune responses in leishmaniasis.

Luciana Girotto, Gentil; Fernanda, Lasakosvitsch; José Franco da, Silveira; Márcia Regina Machado dos, Santos; Clara Lúcia, Barbiéri.

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Analysis and chromosomal mapping of Leishmania (Leishmania) amazonensis amastigote expressed sequence tags  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The characterization of expressed sequence tags (ESTs) generated from a cDNA library of Leishmania (Leishmania) amazonensis amastigotes is described. The sequencing of 93 clones generated new L. (L.) amazonensis ESTs from which 32% are not related to any other sequences in database and 68% presented [...] significant similarities to known genes. The chromosome localization of some L. (L.) amazonensis ESTs was also determined in L. (L.) amazonensis and L. (L.) major. The characterization of these ESTs is suitable for the genome physical mapping, as well as for the identification of genes encoding cysteine proteinases implicated with protective immune responses in leishmaniasis.

Luciana Girotto, Gentil; Fernanda, Lasakosvitsch; José Franco da, Silveira; Márcia Regina Machado dos, Santos; Clara Lúcia, Barbiéri.

2007-09-01

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Serological reactivity of different antigenic preparations of Leishmania (Leishmania amazonensis and the Leishmania braziliensis complex Reatividade sorológica frente a diferentes preparações antigênicas de Leishmania (Leishmania amazonensis e do complexo Leishmania braziliensis  

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Full Text Available Total antigen from Leishmania (Leishmania amazonensis and isolates from the Leishmania braziliensis complex, along with their respective antigenic fractions obtained by affinity chromatography on concanavalin-A-Sepharose and jacalin-agarose columns evaluated using immunoenzymatic ELISA assay. For this, serum samples from 229 patients were used, grouped as American tegmental leishmaniasis (nº=58, visceral leishmaniasis (nº=28, Chagas disease (nº=49, malaria (nº=32, tuberculosis (nº=13 and healthy volunteers (nº=49. Samples from American tegmentary leishmaniasis showed higher reactivity with antigens isolated from the Leishmania braziliensis complex than with antigens from Leishmania amazonensis (pAntígeno total de Leishmania (Leishmania amazonensis e isolado do complexo Leishmania brazilienis, assim como suas respectivas frações antigênicas obtidas por cromatografia de afinidade em coluna de concanavalina-A ligada a sepharose e Jacalina ligada a agarose foram avaliadas por ensaio imunoenzimático ELISA. Para tanto, foram utilizadas amostras de soros de 229 pacientes agrupadas em leishmaniose tegumentar americana (nº=58, leishmaniose visceral (nº=28, doença de Chagas (nº=49, malaria (nº=32, tuberculose (nº=13 e voluntários saudáveis (nº=49. Houve maior reatividade das amostras de leishmaniose tegumentar americana com a utilização dos antígenos obtidos do isolado do complexo Leishmania braziliensis quando comparado com antígenos de Leishmania amazonensis (p<0,001. Observou-se ainda que a sensibilidade do teste ELISA variou de 60 a 95% entre os antígenos obtidos do isolado do complexo Leishmania braziliensis. Houve acentuada reatividade inespecífica das amostras de soros com a utilização das frações antigênicas ligantes de Concanavalina-A e Jacalina de ambos os complexos Leishmania em comparação aos demais antígenos (p<0,001. Os resultados apresentados no presente trabalho sugerem que a utilização de antígenos homólogos aumentam a eficiência de detecção de imunoglobulina anti-Leishmania o que pode ser de grande valia para o propósito de diagnóstico.

Adriano Gomes-Silva

2008-04-01

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Serological reactivity of different antigenic preparations of Leishmania (Leishmania) amazonensis and the Leishmania braziliensis complex Reatividade sorológica frente a diferentes preparações antigênicas de Leishmania (Leishmania) amazonensis e do complexo Leishmania braziliensis  

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Total antigen from Leishmania (Leishmania) amazonensis and isolates from the Leishmania braziliensis complex, along with their respective antigenic fractions obtained by affinity chromatography on concanavalin-A-Sepharose and jacalin-agarose columns evaluated using immunoenzymatic ELISA assay. For this, serum samples from 229 patients were used, grouped as American tegmental leishmaniasis (nº=58), visceral leishmaniasis (nº=28), Chagas disease (nº=49), malaria (nº=32), tuberculosis (nº=1...

Adriano Gomes-Silva; Maria Aparecida Souza; Sandra Regina Afonso-Cardoso; Lívia Resende Andrade; Reynaldo Dietze; Elenice Lemos; Alejandro Belli; Silvio Favoreto Júnior; Marcelo Simão Ferreira

2008-01-01

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

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

Patrícia Mendes Pereira

2012-02-01

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

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

Elsa, Nieves; Maritza, Rondón.

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

Scientific Electronic Library Online (English)

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

Elsa, Nieves; Maritza, Rondón.

2010-12-01

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Assembly of the Leishmania amazonensis flagellum during cell differentiation.  

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The flagellar cytoskeleton of Leishmania promastigotes contains the canonical 9+2 microtubular axoneme and a filamentous structure, the paraflagellar rod (PFR), which is present alongside the axoneme. In contrast to promastigotes, which contain a long and motile flagellum, the amastigote form of Leishmania displays a short flagellum without a PFR that is limited to the flagellar pocket domain. Here, we investigated the biogenesis of the Leishmania flagellum at 0, 4, 6 and 24h of differentiation. Light and electron microscopy observations of the early stages of L. amazonensis differentiation showed that the intermediate forms presented a short and wider flagellum that did not contain a PFR and presented reduced motion. 3D-reconstruction analysis of electron tomograms revealed the presence of vesicles and electron-dense aggregates at the tip of the short flagellum. In the course of differentiation, cells were able to adhere and proliferate with a doubling time of about 6h. The new flagellum emerged from the flagellar pocket around 4h after initiation of cell cycle. Close contact between the flagellar membrane and the flagellar pocket membrane was evident in the intermediate forms. At a later stage of differentiation, intermediate cells exhibited a longer flagellum (shorter than in promastigotes) that contained a PFR and electron dense aggregates in the flagellar matrix. In some cells, PFR profiles were observed inside the flagellar pocket. Taken together, these data contribute to the understanding of flagellum biogenesis and organisation during L. amazonensis differentiation. PMID:24041804

Gadelha, Ana Paula Rocha; Cunha-e-Silva, Narcisa Leal; de Souza, Wanderley

2013-11-01

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Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation  

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

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

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

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

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

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

Reynolds K. B. Brobey

2006-02-01

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Neutrophils Reduce the Parasite Burden in Leishmania (Leishmania) amazonensis-Infected Macrophages  

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Background 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. Methodology/Principal Findings 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-?), 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-?, as reported for other Leishmania species. Conclusions/Significance 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. PMID:21082032

de Souza Carmo, Erico Vinicius; Katz, Simone; Barbieri, Clara Lucia

2010-01-01

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Resistance of Leishmania (Leishmania amazonensis and Leishmania (Viannia braziliensis to nitric oxide correlates with disease severity in Tegumentary Leishmaniasis  

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Full Text Available Abstract Background Nitric oxide (NO• plays a pivotal role as a leishmanicidal agent in mouse macrophages. NO• resistant Escherichia coli and Mycobacterium tuberculosis have been associated with a severe outcome of these diseases. Methods In this study we evaluated the in vitro toxicity of nitric oxide for the promastigote stages of Leishmania (Viannia braziliensis and Leishmania (Leishmania amazonensis parasites, and the infectivity of the amastigote stage for human macrophages. Parasites were isolated from patients with cutaneous, mucosal or disseminated leishmaniasis, and NO• resistance was correlated with clinical presentation. Results Seventeen isolates of L. (L. amazonensis or L. (V. braziliensis promastigotes were killed by up to 8 mM of more of NaNO2 (pH 5.0 and therefore were defined as nitric oxide-susceptible. In contrast, eleven isolates that survived exposure to 16 mM NaNO2 were defined as nitric oxide-resistant. Patients infected with nitric oxide-resistant Leishmania had significantly larger lesions than patients infected with nitric oxide-susceptible isolates. Furthermore, nitric oxide-resistant L. (L. amazonensis and L. (V. braziliensis multiplied significantly better in human macrophages than nitric oxide-susceptible isolates. Conclusion These data suggest that nitric oxide-resistance of Leishmania isolates confers a survival benefit for the parasites inside the macrophage, and possibly exacerbates the clinical course of human leishmaniasis.

Carvalho Edgar M

2007-02-01

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Leishmania (Viannia) braziliensis growth in vitro culture relies more on folic acid availability than Leihsmania (Leishmania) amazonensis  

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We compared the in vitro growth of promastigotes from two Leishmania species in TC-100 and Schneider media. Leishmania (Leishmania) amazonensis replication rates were similar in both tissue culture media and reached maximum rates by 48 h. In contrast Leishmania (Viannia) braziliensis growth was significantly greater in TC-100 but maximum rates were achieved by 96 h. Folic acid appears to be the limiting factor and supplementation of Schneider media with this nutrient improved L. (V.) brazilie...

Andrea Niño; Marcela Camacho

2005-01-01

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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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Full Text Available SciELO Brazil | Language: English Abstract in english 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 spp. was intraperitoneally inoculated in five groups of six animals each and the cell migration was analyzed 0, 3, 6, 12, 24 and 48 hours after infection. Different cell counts were performed with a staining kit and showed a higher percentage of polymorphonuclear than mononuclear cells in all three species studied. The total cell count revealed peak migration in L. (L.) amazonensis and L. (L.) major at six hours, and in L. (V.) braziliensis at 12 hours. These results suggest that factors released from different cell types probably act by attracting polymorphonuclear cells, with the peak migration most likely depending on the species of Leishmania inoculated into the host.

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

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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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Full Text Available 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 spp. was intraperitoneally inoculated in five groups of six animals each and the cell migration was analyzed 0, 3, 6, 12, 24 and 48 hours after infection. Different cell counts were performed with a staining kit and showed a higher percentage of polymorphonuclear than mononuclear cells in all three species studied. The total cell count revealed peak migration in L. (L. amazonensis and L. (L. major at six hours, and in L. (V. braziliensis at 12 hours. These results suggest that factors released from different cell types probably act by attracting polymorphonuclear cells, with the peak migration most likely depending on the species of Leishmania inoculated into the host.

DT Wakimoto

2010-01-01

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

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

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

2005-06-01

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

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

MARÍA ALEJANDRA VIVENES

2005-06-01

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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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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.

Raquel S. Pacheco

1987-12-01

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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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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 s...

Pacheco, Raquel S.; Gabriel Grimaldi Júnior; Morel, Carlos M.

1987-01-01

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The leishmanicidal flavonols quercetin and quercitrin target Leishmania (Leishmania) amazonensis arginase.  

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Polyamine biosynthesis enzymes are promising drug targets for the treatment of leishmaniasis, Chagas' disease and African sleeping sickness. Arginase, which is a metallohydrolase, is the first enzyme involved in polyamine biosynthesis and converts arginine into ornithine and urea. Ornithine is used in the polyamine pathway that is essential for cell proliferation and ROS detoxification by trypanothione. The flavonols quercetin and quercitrin have been described as antitrypanosomal and antileishmanial compounds, and their ability to inhibit arginase was tested in this work. We characterized the inhibition of recombinant arginase from Leishmania (Leishmania) amazonensis by quercetin, quercitrin and isoquercitrin. The IC(50) values for quercetin, quercitrin and isoquercitrin were estimated to be 3.8, 10 and 4.3 ?M, respectively. Quercetin is a mixed inhibitor, whereas quercitrin and isoquercitrin are uncompetitive inhibitors of L. (L.) amazonensis arginase. Quercetin interacts with the substrate l-arginine and the cofactor Mn(2+) at pH 9.6, whereas quercitrin and isoquercitrin do not interact with the enzyme's cofactor or substrate. Docking analysis of these flavonols suggests that the cathecol group of the three compounds interact with Asp129, which is involved in metal bridge formation for the cofactors Mn(A)(2+) and Mn(B)(2+) in the active site of arginase. These results help to elucidate the mechanism of action of leishmanicidal flavonols and offer new perspectives for drug design against Leishmania infection based on interactions between arginase and flavones. PMID:22327179

da Silva, Edson Roberto; Maquiaveli, Claudia do Carmo; Magalhães, Prislaine Pupolin

2012-03-01

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

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

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Activation of the MAPK, ERK, following Leishmania amazonensis Infection of Macrophages1  

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IL-10 is a critical cytokine in determining host susceptibility to Leishmania spp. We previously demonstrated that macrophage-derived IL-10 could contribute to disease exacerbation, but the mechanisms whereby Leishmania infections led to IL-10 induction were not fully understood. In this study, we demonstrated that infection of macrophages with Leishmania amazonensis amastigotes led to the activation of the MAPK, ERK1/2. This activation was required, but not sufficient for IL-10 induction. In...

Yang, Ziyan; Mosser, David M.; Zhang, Xia

2007-01-01

59

Leishmania (Viannia braziliensis growth in vitro culture relies more on folic acid availability than Leihsmania (Leishmania amazonensis  

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Full Text Available We compared the in vitro growth of promastigotes from two Leishmania species in TC-100 and Schneider media. Leishmania (Leishmania amazonensis replication rates were similar in both tissue culture media and reached maximum rates by 48 h. In contrast Leishmania (Viannia braziliensis growth was significantly greater in TC-100 but maximum rates were achieved by 96 h. Folic acid appears to be the limiting factor and supplementation of Schneider media with this nutrient improved L. (V. braziliensis replication rates and decreased the time of maximum replication to 48 h.

Andrea Niño

2005-05-01

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Leishmania (Viannia) braziliensis growth in vitro culture relies more on folic acid availability than Leihsmania (Leishmania) amazonensis  

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Full Text Available SciELO Brazil | Language: English Abstract in english We compared the in vitro growth of promastigotes from two Leishmania species in TC-100 and Schneider media. Leishmania (Leishmania) amazonensis replication rates were similar in both tissue culture media and reached maximum rates by 48 h. In contrast Leishmania (Viannia) braziliensis growth was sign [...] ificantly greater in TC-100 but maximum rates were achieved by 96 h. Folic acid appears to be the limiting factor and supplementation of Schneider media with this nutrient improved L. (V.) braziliensis replication rates and decreased the time of maximum replication to 48 h.

Andrea, Niño; Marcela, Camacho.

 
 
 
 
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Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi  

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Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonensis, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the par...

Melo E. J. T.; Beiral H.J.

2003-01-01

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

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae) e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania) amazonensis, situada no município de Bela Vista, Estado d [...] o Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus auratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local. Abstract in english INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. M [...] ETHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

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

2010-10-01

63

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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Full Text Available INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3% and Bi flaviscutellata (41.4%, present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania amazonensis, situada no município de Bela Vista, Estado do Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus auratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local.

Maria Elizabeth Cavalheiros Dorval

2010-10-01

64

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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Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: O estudo foi realizado com o objetivo de estudar a fauna de flebotomíneos (Diptera: Psychodidae) e aspectos ligados à transmissão da leishmaniose tegumentar americana em uma área florestal com ocorrência de Leishmania (Leishmania) amazonensis, situada no município de Bela Vista, Estado d [...] o Mato Grosso do Sul, Brasil. MÉTODOS: As capturas de flebotomíneos foram realizadas utilizando-se armadilhas tipo Disney modificadas, com isca roedor, Mesocricetus auratus, no período de maio de 2004 a janeiro de 2006. RESULTADOS: As coletas resultaram na identificação de 10 espécies de Phlebotominae: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni e Sciopemyia sordellii. As duas espécies predominantes foram Ev bourrouli, com 57,3% dos espécimes coletados, e Bi. flaviscutellata, representada por 41,4% e que esteve presente em todos os locais amostrados. Dois hamsters sentinelas adquiriram a infecção natural, sendo os isolados identificados como Leishmania amazonensis. CONCLUSÕES: Os resultados mostram a eficiência das armadilhas Disney para captura de Bichromomyia flaviscutellata, e a presença simultânea de ambos, o vetor e a espécie de Leishmania por ele transmitida pode ser considerada um fator preditor da ocorrência de leishmaniose para a população humana que permanecer nesse local. Abstract in english INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. M [...] ETHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

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

65

Persistence of Leishmania antigen in C57Bl/6j inbred mice infected with Leishmania (Leishmania amazonensis  

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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.

Vasconcellos C.

1999-01-01

66

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

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

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

2013-09-01

67

Diseminación tisular y efectos histopatológicos producidos por Leishmania mexicana amazonensis en roedores infectados experimentalmente / Tissue dissemination and histopathology effects produced by Leishmania mexicana amazonensis in rodents experimentally infected  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Al género Leishmania pertenecen diferentes especies responsables de diversas formas clínicas de leishmaniasis. En este trabajo comparamos los efectos histopatológicos producidos en hamsters (Mesocricetus auratus) y ratones (Mus musculus) infectados experimentalmente por vía subcutánea con 20 x 10(5) [...] amastigotes de Leishmania mexicana amazonensis. Nuestros resultados mostraron en hamsters daños histopatológicos en intestino, escroto, testículo, epidídimo, bazo, hígado, riñón, corazón y pulmón y en ratones en testículo, bazo, riñón y corazón. Estos resultados evidencian diferencias en la diseminación tisular, metástasis cutáneas, efectos histopatológicos y mortalidad, siendo más amplios, tempranos y graves en hamsters que en ratones. Abstract in english Leishmania comprises different species responsible of a variety of clinical forms of leishmaniasis. In this investigation we compared the histopathological effects produced in hamsters (Mesocricetus auratus) and mice (Mus musculus), inoculated by the subcutaneous route with 20 x 10(5) amastigotes of [...] Leishmania mexicana amazonensis. Our results in hamsters show tissue damage in gut, scrotum, testicle, epididimus, spleen, liver, kidney, heart and lung and in mice we found histopathological changes in testicle, spleen, kidney and heart. These results show differences on tissue dissemination, cutaneous metastasis, histopathological effects and mortality, being more extensive, early and severe in hamsters then in mice.

Elizabeth, Bruzual; Lucila, Arcay; María Antonia, de la Parte-Pérez.

2008-12-01

68

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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Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 óle [...] o 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. Abstract in english 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 comb [...] ination 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.

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

2007-08-01

69

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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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.

Lianet Monzote

2007-08-01

70

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

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

Letícia Oba Galvão

2000-08-01

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

Scientific Electronic Library Online (English)

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

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

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An In Vitro Model of Antibody-Enhanced Killing of the Intracellular Parasite Leishmania amazonensis  

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Footpad infection of C3HeB/FeJ mice with Leishmania amazonensis leads to chronic lesions accompanied by large parasite loads. Co-infecting these animals with L. major leads to induction of an effective Th1 immune response that can resolve these lesions. This cross-protection can be recapitulated in vitro by using immune cells from L. major-infected animals to effectively activate L. amazonensis-infected macrophages to kill the parasite. We have shown previously that the B cell population and their IgG2a antibodies are required for effective cross-protection. Here we demonstrate that, in contrast to L. major, killing L. amazonensis parasites is dependent upon FcR? common-chain and NADPH oxidase-generated superoxide from infected macrophages. Superoxide production coincided with killing of L. amazonensis at five days post-activation, suggesting that opsonization of the parasites was not a likely mechanism of the antibody response. Therefore we tested the hypothesis that non-specific immune complexes could provide a mechanism of FcR? common-chain/NADPH oxidase dependent parasite killing. Macrophage activation in response to soluble IgG2a immune complexes, IFN-? and parasite antigen was effective in significantly reducing the percentage of macrophages infected with L. amazonensis. These results define a host protection mechanism effective during Leishmania infection and demonstrate for the first time a novel means by which IgG antibodies can enhance killing of an intracellular pathogen. PMID:25191842

Gibson-Corley, Katherine N.; Bockenstedt, Marie M.; Li, Huijuan; Boggiatto, Paola M.; Phanse, Yashdeep; Petersen, Christine A.; Bellaire, Bryan H.; Jones, Douglas E.

2014-01-01

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The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A Leishmania amazonensis é o principal agente etiológico da leishmaniose cutânea difusa, uma doença associada a respostas imunes anérgicas. Neste estudo nós mostramos que o extrato bruto de promastigotas de Leishmania amazonensis (LaAg), mas não de L. braziliensis (LbAg), contém substâncias que supr [...] imem respostas proliferativas, espontâneas e mitogênicas, de células T. As substâncias supressoras no LaAg são termo-resistentes (100°C/1h) e parcialmente dependentes da atividade de proteases. A anergia de células T não foi devida à diminuição na produção de fatores de crescimento, uma vez que não foi revertida pela adição de: IL-2, IL-4, IFN-gama ou IL-12. O LaAg não inibiu a ativação de células T induzida por anti-CD3, sugerindo que a anergia é devida a um defeito na apresentação de antígenos. A anergia não foi devida à necrose celular, mas foi acompanhada de uma expressiva fragmentação de DNA nas células de linfonodos, indicativo de apoptose. Apesar da pré-incubação de macrófagos com LaAg ter inibido sua capacidade de apresentação de antigenos, este efeito não foi devido à apoptose dos primeiros. Estes resultados sugerem que a anergia de células T encontrada na leishmaniose difusa deve ser devida à apoptose dessas células que se segue à apresentação defeituosa de antígenos pelo antígeno do parasito. Abstract in english Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and [...] spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.

Roberta O., Pinheiro; Eduardo F., Pinto; Alessandra B., Benedito; Ulisses G., Lopes; Bartira, Rossi-Bergmann.

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Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi  

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Full Text Available Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase on the multiplication of L. amazonensis, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97% and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic morphologic alterations or disruption. The results strongly suggest that hydroxyurea was able to interfere with the multiplication of intracellular parasites, leading to an irreversible morphological effect on L. amazonensis, T. gondii, and T. cruzi without affecting the host cells.

Melo E.J.T.

2003-01-01

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Daño ultraestructural del intestino medio abdominal de Lutzomyia ovallesi (Ortiz (Diptera: Psychodidae ocasionado por Leishmania (Leishmania amazonensis ULTRASTRUCTURAL DAMAGE TO THE MIDDLE INTESTINE OF Lutzomyia ovallesi (Ortiz (DIPTERA: PSYCHODIDAE CAUSED BY Leishmania (Leishmania amazonensis  

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Full Text Available Se estudió el intestino medio abdominal de Lutzomyia ovallesi infectada con Leishmania (Leishmania amazonensis. Las hembras se observaron a los siete días post- infección, utilizando microscopía de luz de alta resolución y microscopía electrónica de transmisión. Se distinguieron dos tipos de células epiteliales, células digestivas y células secretoras, en el intestino medio abdominal de L. ovallesi, tanto en los insectos controles como en flebotominos infectados. Los resultados muestran además, que L. ovallesi presentó alteraciones en la citoar-quitectura celular del intestino medio abdominal producto de la infección con L. (L. amazonensis, observándose gran distensión del diámetro de la luz intestinal, degeneración de sus células, pérdida parcial o total de las microvellosidades y engrosamiento de la capa basal de toda la porción del intestino. Las células epiteliales presentaron degeneración vacuolar y mitocondrial y en la luz intestinal se observaron desechos epiteliales. El daño celular observado en el intestino medio abdominal de L. ovallesi, pueden tener relación con la secreción de lectinas y con la formación del gel observado, semejante a una matriz, en el lumen del intestino. Es necesario continuar los estudios para dilucidar aspectos importantes de la interrelación Leishmania-vector.A study was done in the middle intestine of Lutzomyia ovallesi infected with Leishmania (Leishmania amzonensis. The females were examined seven days after infection by means of high resolution light microscopy and transmission electron microscopy. Two kinds of epithelial cells, digestive and secretory, were observed in the middle intestine of L. ovallesi, in both control insects and in those infected. Results showed changes in the cytoarchitecture of the intestine as a consequence of infection with L. (L. amazonensis. There was a great increase in the diameter of the intestine, showing signs of cellular degeneration, such as partial or total loss of microvilli and the thickening of the basal layer of the whole portion of the intestine. Epithelial cells showed damage in vacuoles and mitochondria, and epithelial waste was observable in the intestine. Cellular damage in the middle intestine of L. ovallesi produced by infection with L. (L. amazonensis is perhaps connected with lectin secretion and formation of gel, similar to that of a matrix, in the intestinal lumen. More studies are needed to clarify important aspects of the relationship between Leishmania and the vector.

ELSA NIEVES

2004-07-01

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Characterization of cellular immune response to chemically defined glycoconjugates from Leishmania mexicana subsp. amazonensis.  

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Two defined glycoconjugates (GP-10/20 and FR II Phe) purified from Leishmania mexicana subsp. amazonensis were analyzed with respect to their ability to induce cellular responses in immunized and infected mice. Each glycoconjugate was recognized by specific immune cells, as assessed by the proliferative response of lymph node cells of immunized mice. The response to GP-10/20 depended on helper T cells and antigen-presenting cells and was restricted by a major histocompatibility complex class ...

Rodrigues, M. M.; Xavier, M. T.; Previato, L. M.; Barcinski, M. A.

1986-01-01

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Nitric Oxide-Mediated Proteasome-Dependent Oligonucleosomal DNA Fragmentation in Leishmania amazonensis Amastigotes  

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Resistance to leishmanial infections depends on intracellular parasite killing by activated host macrophages through the l-arginine-nitric oxide (NO) metabolic pathway. Here we investigate the cell death process induced by NO for the intracellular protozoan Leishmania amazonensis. Exposure of amastigotes to moderate concentrations of NO-donating compounds (acidified sodium nitrite NaNO2 or nitrosylated albumin) or to endogenous NO produced by lipopolysaccharide or gamma interferon treatment o...

Holzmuller, Philippe; Sereno, Denis; Cavaleyra, Mireille; Mangot, Isabelle; Daulouede, Sylvie; Vincendeau, Philippe; Lemesre, Jean-loup

2002-01-01

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Cyclic 3'-5' guanosine monophosphate-dependent activity in Leishmania amazonensis  

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Full Text Available Although there are some data concerning the nitric oxide and the cyclic 3'-5'guanosine monophosphate (cGMP signaling pathway in trypanosomatids, there is no report about the cGMP-dependent enzymatic activity identification. In this sense, a cGMP dependent activity was detected on soluble fraction from Leishmania amazonensis promastigotes with a high metacyclic level. This information is valuable in order to explore the metabolic pathway of G kinase protein in this parasite.

Géigel LF

2003-01-01

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

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As leishmanioses são zoonoses endêmicas em Mato Grosso do Sul e têm por agentes etiológicos nessa região Leishmania (Leishmania) chagasi, Leishmania (Leishmania) amazonensis e Leishmania (Viannia) braziliensis. Como método para identificação de espécies de Leishmania, a reação em cadeia da polimerase é uma ferramenta com elevada especificidade e sensibilidade. Analisaram-se 39 isolados de Leishmania criopreservados, obtidos por meio de aspirado medular e/ou biópsia de lesão, con...

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

2009-01-01

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Immune Responses Induced by the Leishmania (Leishmania) donovani A2 Antigen, but Not by the LACK Antigen, Are Protective against Experimental Leishmania (Leishmania) amazonensis Infection  

Science.gov (United States)

Leishmania amazonensis is one of the major etiologic agents of a broad spectrum of clinical forms of leishmaniasis and has a wide geographical distribution in the Americas, which overlaps with the areas of transmission of many other Leishmania species. The LACK and A2 antigens are shared by various Leishmania species. A2 was previously shown to induce a potent Th1 immune response and protection against L. donovani infection in BALB/c mice. LACK is effective against L. major infection, but no significant protection against L. donovani infection was observed, in spite of the induction of a potent Th1 immune response. In an attempt to select candidate antigens for an American leishmaniasis vaccine, we investigated the protective effect of these recombinant antigens (rLACK and rA2) and recombinant interleukin-12 (rIL-12) against L. amazonensis infection in BALB/c mice. As expected, immunization with either rA2-rIL-12 or rLACK-rIL-12 induced a robust Th1 response prior to infection. However, only the BALB/c mice immunized with rA2-rIL-12 were protected against infection. Sustained gamma interferon (IFN-?) production, high levels of anti-A2 antibodies, and low levels of parasite-specific antibodies were detected in these mice after infection. In contrast, mice immunized with rLACK-rIL-12 displayed decreased levels of IFN-? and high levels of both anti-LACK and parasite-specific antibodies. Curiously, the association between rA2 and rLACK antigens in the same vaccine completely inhibited the rA2-specific IFN-? and humoral responses and, consequently, the protective effect of the rA2 antigen against L. amazonensis infection. We concluded that A2, but not LACK, fits the requirements for a safe vaccine against American leishmaniasis. PMID:12819086

Coelho, Eduardo Antonio Ferraz; Tavares, Carlos Alberto Pereira; Carvalho, Fernando Aecio Amorim; Chaves, Karina Figueiredo; Teixeira, Kadima Nayara; Rodrigues, Rafaela Chitarra; Charest, Hugues; Matlashewski, Greg; Gazzinelli, Ricardo Tostes; Fernandes, Ana Paula

2003-01-01

 
 
 
 
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Immunopathogenic competences of Leishmania (V.) braziliensis and L. (L.) amazonensis in American cutaneous leishmaniasis.  

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The immunopathogenic competences of Leishmania (V.) braziliensis and L. (L.) amazonensis were reviewed in the light of more recent features found in the clinical and immunopathological spectrum of American cutaneous leishmaniasis. It was shown a dichotomy in the interaction between these Leishmania species and human T-cell immune response; while L. (V.) braziliensis shows a clear tendency to lead infection from the localized cutaneous leishmaniasis (LCL), a moderate T-cell hypersensitivity form at the centre of the spectrum, toward to the mucocutaneous leishmaniasis (MCL) at the T-cell hypersensitivity pole and with a prominent Th1-type immune response, L. (L.) amazonensis shows an opposite tendency, leading infection to the anergic diffuse cutaneous leishmaniasis (ADCL) at the T-cell hyposensitivity pole and with a marked Th2-type immune response. Between the central LCL and the two polar MCL and ADCL, the infection can present an intermediary form known as borderline disseminated cutaneous leishmaniasis, characterized by an incomplete inhibition of T-cell hypersensitivity but with a evident supremacy of Th1 over Th2 immune response (Th1 > or = Th2). These are probably the main immunopathogenic competences of L. (V.) braziliensis and L. (L.) amazonensis regarding the immune response dichotomy that modulates human infection outcome by these Leishmania parasites. PMID:19646206

Silveira, F T; Lainson, R; De Castro Gomes, C M; Laurenti, M D; Corbett, C E P

2009-08-01

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Dietary flavonoids fisetin, luteolin and their derived compounds inhibit arginase, a central enzyme in Leishmania (Leishmania) amazonensis infection.  

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Fisetin, quercetin, luteolin and 7,8-hydroxyflavone show high activity in Leishmania cultures and present low toxicity to mammalian cells. In this work, the structural aspects of 13 flavonoids were analyzed for their inhibition of the arginase enzyme from Leishmania (Leishmania) amazonensis. A higher potency of arginase inhibition was observed with fisetin, which was four and ten times greater than that of quercetin and luteolin, respectively. These data show that the hydroxyl group at position 3 contributed significantly to the inhibitory activity of arginase, while the hydroxyl group at position 5 did not. The absence of the catechol group on apigenin drastically decreased arginase inhibition. Additionally, the docking of compounds showed that the inhibitors interact with amino acids involved in the Mn(+2)-Mn(+2) metal bridge formation at the catalytic site. Due to the low IC50 values of these flavonoids, they may be used as a food supplement in leishmaniasis treatment. PMID:23870955

Manjolin, Leticia Correa; dos Reis, Matheus Balduíno Goncalves; Maquiaveli, Claudia do Carmo; Santos-Filho, Osvaldo Andrade; da Silva, Edson Roberto

2013-12-01

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Leishmania mexicana amazonensis: plasma membrane adenine nucleotide translocator and chemotaxis.  

Science.gov (United States)

Leishmania cannot synthesize purines de novo and rely on their host to furnish these compounds. To accomplish this, they possess multiple purine nucleoside and nucleobase transporters. Subcellular fractionation, immunohistochemical localization with anti-adenine nucleotide translocator (ANT) antibodies and surface biotinylation show that the mitochondrial ANT is also present in the plasma membrane of both promastigotes and amastigotes. Leishmania, however, do not appear to rely on this transporter to supplement their purine or energy requirements via preformed ATP from its host. Rather, Leishmania appear to use the plasma membrane ANT as part of a chemotaxis response. ATP is a chemorepellant for Leishmania and cells treated with atractyloside, an inhibitor of ANT, no longer exhibit negative chemotaxis for this compound. PMID:18031742

Detke, S; Elsabrouty, R

2008-03-01

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

International Nuclear Information System (INIS)

Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK2 mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of 60Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

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Antigenic differences among Leishmania amazonensis isolates and their relationship with distinct clinical forms of the disease  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Immunoblot analysis was used to investigate antigenic differences among clinical isolates of Leishmania amazonensis and their role in the etiology of the diseases. Western blots of promastigote homogenates were analyzed with either monoclonal antibodies (MAbs) specific for the L. mexicana complex (M [...] -4, M-6, M-9 and M-11) or polyclonal sera from L. amazonensis infected patients with the various forms of clinical disease. In the case of the MAbs, no significant variation was observed among the strains of L. amazonensis, isolated from cases of cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), diffuse cutaneous leishmaniasis (DCL), visceral leishmaniasis (VL) or post kala-azar dermal leishmaniasis (PKDL), in either the relative morbility (Mr) or the quantitative amount (intensity) of the antigenic determinats. In the case of the sera of the infected patients, the patterns of antigenic reactivity of these strains revealed that, despite showing the presence of shared antigens, differences were observed between some of the antigenic components of the various isolates of L. amazonensis that were recognized by a single serum. Differences were also demonstrated between the antigenic determinants of a single isolate of L. amazonensis that were recognized by the different patient's sera. No apparent association was consistently found, however, between the Mr components identified in these isolates and clinical form of the disease or the geographical area of isolation. In addition, the spectrum of antigens recognized by the sera from patients with the same clinical form were not identical; although in some instances, similar Mr antigens were shared. These results indicate that isolates of L. amazonensis are not antigenically identical (homogeneous) and that the immune responses (antibodies) observed among infected patients are heterogeneous.

Leonor L., Leon; Gerzia M. C., Machado; Aldina, Barral; Luiz E. de, Carvalho-Paes; Gabriel, Grimaldi Júnior.

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

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

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

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

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

Manoel Sebastião da Costa Lima Junior

2009-06-01

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Activity of Cuban Plants Extracts against Leishmania amazonensis  

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Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Le...

Pedro Herrera; Ramón Scull; Lianet Monzote; Marley García

2012-01-01

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A comparison of two distinct murine macrophage gene expression profiles in response to Leishmania amazonensis infection  

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Full Text Available Abstract Background The experimental murine model of leishmaniasis has been widely used to characterize the immune response against Leishmania. CBA mice develop severe lesions, while C57BL/6 present small chronic lesions under L. amazonensis infection. Employing a transcriptomic approach combined with biological network analysis, the gene expression profiles of C57BL/6 and CBA macrophages, before and after L. amazonensis infection in vitro, were compared. These strains were selected due to their different degrees of susceptibility to this parasite. Results The genes expressed by C57BL/6 and CBA macrophages, before and after infection, differ greatly, both with respect to absolute number as well as cell function. Uninfected C57BL/6 macrophages express genes involved in the deactivation pathway of macrophages at lower levels, while genes related to the activation of the host immune inflammatory response, including apoptosis and phagocytosis, have elevated expression levels. Several genes that participate in the apoptosis process were also observed to be up-regulated in C57BL/6 macrophages infected with L. amazonensis, which is very likely related to the capacity of these cells to control parasite infection. By contrast, genes involved in lipid metabolism were found to be up-regulated in CBA macrophages in response to infection, which supports the notion that L. amazonensis probably modulates parasitophorous vacuoles in order to survive and multiply in host cells. Conclusion The transcriptomic profiles of C57BL/6 macrophages, before and after infection, were shown to be involved in the macrophage pathway of activation, which may aid in the control of L. amazonensis infection, in contrast to the profiles of CBA cells.

Probst Christian M

2012-02-01

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Specific immunization of mice against Leishmania mexicana amazonensis using solubilized promastigotes  

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In this work, it was demonstrated that mice (BALB/c strain) highly susceptible to Leishmania mexicana amazonensis can be protected against infection by this parasite by being preimmunized with whole solubilized (in a buffer that contained EDTA, NP-40, and SDS) promastigotes; the use of adjuvant or intact inactivated parasite cells is shown to be not necessary. The best immunization schedule consisted of three intravenous injections of 5 x 10 to the 7th parasite equivalents, administered one to eight weeks before infection. Immunized mice exhibited a marked inhibition of primary lesion development, reduced numbers of parasites in the spleen, and reduced death rate.

Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.

1987-01-01

91

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

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

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Cyclic 3'-5' guanosine monophosphate-dependent activity in Leishmania amazonensis  

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Full Text Available SciELO Brazil | Language: English Abstract in english Although there are some data concerning the nitric oxide and the cyclic 3'-5'guanosine monophosphate (cGMP) signaling pathway in trypanosomatids, there is no report about the cGMP-dependent enzymatic activity identification. In this sense, a cGMP dependent activity was detected on soluble fraction f [...] rom Leishmania amazonensis promastigotes with a high metacyclic level. This information is valuable in order to explore the metabolic pathway of G kinase protein in this parasite.

LF, Géigel; LL, Leon.

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

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

César A. Cuba Cuba

1990-12-01

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

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

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

95

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

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This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania Amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC50 was 24.8 ?g mL-1. However, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 ?g mL-1, showed a potent inhibitory activity on promastigotes proliferation (IC50 = 3.3 ?g mL-1). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC50 = 3.48 ?g mL-1 and 5.8 ?g mL-1, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. Amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs. (author)

96

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

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

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

2011-07-01

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Resveratrol Is Active against Leishmania amazonensis: In Vitro Effect of Its Association with Amphotericin B.  

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

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

2014-10-01

98

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

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

Daniel Ignacchiti, Lacerda; Léa, Cysne-Finkelstein; Marise Pinheiro, Nunes; Paula Mello, De-Luca; Marcelo da Silva, Genestra; Leonor Laura Pinto, Leon; Marcia, Berrêdo-Pinho; Leila, Mendonça-Lima; Denise Cristina de Souza, Matos; Marco Alberto, Medeiros; Sergio Coutinho Furtado de, Mendonça.

2012-03-01

99

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

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

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

2013-03-01

100

Understanding the Mechanisms Controlling Leishmania amazonensis Infection In Vitro: The Role of LTB4 Derived From Human Neutrophils  

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Neutrophils are rapidly recruited to the site of Leishmania infection and play an active role in capturing and killing parasites. They are the main source of leukotriene B4 (LTB4), a potent proinflammatory lipid mediator. However, the role of LTB4 in neutrophil infection by Leishmania amazonensis is not clear. In this study, we show that L. amazonensis or its lipophosphoglycan can induce neutrophil activation, degranulation, and LTB4 production. Using pharmacological inhibitors of leukotriene synthesis, our findings reveal an LTB4-driven autocrine/paracrine regulatory effect. In particular, neutrophil-derived LTB4 controls L. amazonensis killing, degranulation, and reactive oxygen species production. In addition, L. amazonensis infection induces an early increase in Toll-like receptor 2 expression, which facilitates parasite internalization. Nuclear factor kappa B (NFkB) pathway activation represents a required upstream event for L. amazonensis–induced LTB4 synthesis. These leishmanicidal mechanisms mediated by neutrophil-derived LTB4 act through activation of its receptor, B leukotriene receptor 1 (BLT1). PMID:24634497

Tavares, Natalia Machado; Araujo-Santos, Theo; Afonso, Lilian; Nogueira, Paula Monalisa; Lopes, Ulisses Gazos; Soares, Rodrigo Pedro; Bozza, Patricia Torres; Bandeira-Melo, Christianne; Borges, Valeria Matos; Brodskyn, Claudia

2014-01-01

 
 
 
 
101

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

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese O presente trabalho descreve a atividade do extrato etanólico (EE) dos frutos de Combretum leprosum, do triterpeno 3?, 6?, 16?-triidroxilup-20(29)-eno (1) e seus derivados sintéticos (1a-1d), sobre promastigotas de Leishmaniaamazonensis. O EE apresentou atividade leishmanicida e o valor de IC50 foi [...] de 24,8 µg mL-1. Já o triterpeno 3?, 6?, 16?-trihidroxilup-20(29)-eno (1), na concentração de 5,0 µg mL-1, apresentou uma potente ação inibitória sobre a proliferação das promastigotas (IC50 = 3,3 µg mL-1). Entre os derivados sintéticos, apenas 1b e 1d apresentaram atividade contra as promastigotas (IC50 = 3,48 µg mL-1e 5,8 µg mL-1, respectivamente). Por outro lado, o derivado sintético 1a não apresentou atividade sobre as promastigotas de L. amazonensis. O EE, (1) e os derivados sintéticos 1a-1d não apresentaram efeito citotóxico sobre macrófagos peritoneais de camundongos. Estes resultados fornecem evidencias de que o extrato etanólico e o lupano isolado de C. leprosum possui atividade contra promastigotas de L. amazonensis, podendo ser utilizados como ferramentas no estudo de novas drogas leishmanicidas. Abstract in english This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC50 [...] was 24.8 mg mL-1. However, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 mg mL-1, showed a potent inhibitory activity on promastigotes proliferation (IC50 = 3.3 mg mL-1). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC50 = 3.48 mg mL-1and 5.8 mg mL-1, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs.

Carolina B. G, Teles; Leandro S, Moreira; Alexandre de A. E, Silva; Valdir A, Facundo; Juliana P, Zuliani; Rodrigo G, Stábeli; Izaltina, Silva-Jardim.

102

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

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese O presente trabalho descreve a atividade do extrato etanólico (EE) dos frutos de Combretum leprosum, do triterpeno 3?, 6?, 16?-triidroxilup-20(29)-eno (1) e seus derivados sintéticos (1a-1d), sobre promastigotas de Leishmaniaamazonensis. O EE apresentou atividade leishmanicida e o valor de IC50 foi [...] de 24,8 µg mL-1. Já o triterpeno 3?, 6?, 16?-trihidroxilup-20(29)-eno (1), na concentração de 5,0 µg mL-1, apresentou uma potente ação inibitória sobre a proliferação das promastigotas (IC50 = 3,3 µg mL-1). Entre os derivados sintéticos, apenas 1b e 1d apresentaram atividade contra as promastigotas (IC50 = 3,48 µg mL-1e 5,8 µg mL-1, respectivamente). Por outro lado, o derivado sintético 1a não apresentou atividade sobre as promastigotas de L. amazonensis. O EE, (1) e os derivados sintéticos 1a-1d não apresentaram efeito citotóxico sobre macrófagos peritoneais de camundongos. Estes resultados fornecem evidencias de que o extrato etanólico e o lupano isolado de C. leprosum possui atividade contra promastigotas de L. amazonensis, podendo ser utilizados como ferramentas no estudo de novas drogas leishmanicidas. Abstract in english This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC50 [...] was 24.8 mg mL-1. However, the triterpene 3?, 6?, 16?-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 mg mL-1, showed a potent inhibitory activity on promastigotes proliferation (IC50 = 3.3 mg mL-1). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC50 = 3.48 mg mL-1and 5.8 mg mL-1, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs.

Carolina B. G, Teles; Leandro S, Moreira; Alexandre de A. E, Silva; Valdir A, Facundo; Juliana P, Zuliani; Rodrigo G, Stábeli; Izaltina, Silva-Jardim.

2011-05-01

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In Vitro and In Vivo Miltefosine Susceptibility of a Leishmania amazonensis Isolate from a Patient with Diffuse Cutaneous Leishmaniasis  

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Miltefosine was the first oral compound approved for visceral leishmaniasis chemotherapy, and its efficacy against Leishmania donovani has been well documented. Leishmania amazonensis is the second most prevalent species causing cutaneous leishmaniasis and the main etiological agent of diffuse cutaneous leishmaniasis in Brazil. Driven by the necessity of finding alternative therapeutic strategies for a chronic diffuse cutaneous leishmaniasis patient, we evaluated the susceptibility to miltefosine of the Leishmania amazonensis line isolated from this patient, who had not been previously treated with miltefosine. In vitro tests against promastigotes and intracellular amastigotes showed that this parasite isolate was less susceptible to miltefosine than L. amazonensis type strains. Due to this difference in susceptibility, we evaluated whether genes previously associated with miltefosine resistance were involved. No mutations were found in the miltefosine transporter gene or in the Ros3 or pyridoxal kinase genes. These analyses were conducted in parallel with the characterization of L. amazonensis mutant lines selected for miltefosine resistance using a conventional protocol to select resistance in vitro, i.e., exposure of promastigotes to increasing drug concentrations. In these mutant lines, a single nucleotide mutation G852E was found in the miltefosine transporter gene. In vivo studies were also performed to evaluate the correlation between in vitro susceptibility and in vivo efficacy. Miltefosine was effective in the treatment of BALB/c mice infected with the L. amazonensis type strain and with the diffuse cutaneous leishmaniasis isolate. On the other hand, animals infected with the resistant line bearing the mutated miltefosine transporter gene were completely refractory to miltefosine chemotherapy. These data highlight the difficulties in establishing correlations between in vitro susceptibility determinations and response to chemotherapy in vivo. This study contributed to establish that the miltefosine transporter is essential for drug activity in L. amazonensis and a potential molecular marker of miltefosine unresponsiveness in leishmaniasis patients. PMID:25033218

Coelho, Adriano C.; Trinconi, Cristiana T.; Costa, Carlos H. N.; Uliana, Silvia R. B.

2014-01-01

104

The role of complement in the early phase of Leishmania (Leishmania) amazonensis infection in BALB/c mice  

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Full Text Available SciELO Brazil | Language: English Abstract in english Complement-depleted and -non-depleted BALB/c mice were inoculated with Leishmania (Leishmania) amazonensis promastigotes into the hind footpad to study the role of the complement system in cutaneous leishmaniasis. Total serum complement activity was measured by hemolytic assay and C3 fragment deposi [...] t at the inoculation site was determined by direct immunofluorescence in the early period of infection, i.e., at 3, 24, 48 h and 7 days post-infection. The inflammatory reaction and the parasite burden were evaluated in the skin lesion at 7 and 30 days post-infection. Total serum complement activity decreased in the early phase of infection, from 3 to 24 h, in non-depleted mice compared to non-infected and non-depleted mice. C3 fragment deposit at the site of parasite inoculation was present throughout the period of infection in non-depleted mice. In contrast, no C3 fragment deposit was observed at the inoculation site in complement-depleted mice. Complement-depleted mice showed a significant decrease in the inflammatory response and a significant increase in the number of parasites (70.0 ± 5.3 vs 5.3 ± 1.5) at 7 days of infection (P

M.D., Laurenti; A., Örn; I.L., Sinhorini; C.E.P., Corbett.

2004-03-01

105

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

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

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

106

Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi  

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Full Text Available SciELO Brazil | Language: English Abstract in english Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonens [...] is, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97%) and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic morphologic alterations or disruption. The results strongly suggest that hydroxyurea was able to interfere with the multiplication of intracellular parasites, leading to an irreversible morphological effect on L. amazonensis, T. gondii, and T. cruzi without affecting the host cells.

E.J.T., Melo; H.J., Beiral.

2003-01-01

107

Leishmania amazonensis: effects of oral treatment with copaiba oil in mice.  

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Leishmaniasis is a severe public-health problem, with high rates of morbidity and mortality. Efforts to find new, effective and safe oral agents for the treatment of leishmaniasis have been ongoing for several decades, in order to avoid the problems with the currently used antimonials. In the present study, we found that a copaiba oil oral treatment (Group IV) caused a significant reduction in the average lesion size (1.1±0.4mm) against Leishmania amazonensis lesions compared with untreated mice (Group I) (4.4±1.3mm). To prove the safety of the oil, the toxicity and genotoxicity were also determined. Histopathological evaluation did not reveal changes in the copaiba oil-treated animals compared to the control animals. In the mutagenicity evaluation, (micronucleus test) the dose tested (2000mg/kg) showed no genotoxic effects. Morphological and ultrastructural analyses demonstrated notable changes in parasite cells treated with this oleoresin. The main ultrastructural effect was mitochondrial swelling. We also demonstrated that in vitro copaiba oil treatment of L. amazonensis led to an increase in plasma membrane permeability, and depolarization in the mitochondrial membrane potential in parasite cells. Although the mechanism of action of the oleoresin is still unclear, these findings indicate that copaiba oil is a possible new drug, which would provide a safer, shorter, less-expensive, and more easily administered treatment for leishmaniasis. PMID:21771592

dos Santos, Adriana Oliveira; Costa, Marco Antonio; Ueda-Nakamura, Tânia; Dias-Filho, Benedito Prado; da Veiga-Júnior, Valdir Florêncio; de Souza Lima, Marli Miriam; Nakamura, Celso Vataru

2011-10-01

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Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonens [...] is, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97%) and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic morphologic alterations or disruption. The results strongly suggest that hydroxyurea was able to interfere with the multiplication of intracellular parasites, leading to an irreversible morphological effect on L. amazonensis, T. gondii, and T. cruzi without affecting the host cells.

E.J.T., Melo; H.J., Beiral.

109

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

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

Elsa Nieves

2011-03-01

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

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

Bonetti, Franco Claudio

2002-07-01

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

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

Elisandra Cristina Schinor

2007-06-01

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

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This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium...

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

2005-01-01

113

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

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

Silva-Almeida Mariana

2012-02-01

114

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

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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. PMID:17823757

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

2007-01-01

115

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

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

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

116

In silico predicted epitopes from the COOH-terminal extension of cysteine proteinase B inducing distinct immune responses during Leishmania (Leishmania amazonensis experimental murine infection  

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Full Text Available Abstract Background Leishmania parasites have been reported to interfere and even subvert their host immune responses to enhance their chances of survival and proliferation. Experimental Leishmania infection in mice has been widely used in the identification of specific parasite virulence factors involved in the interaction with the host immune system. Cysteine-proteinase B (CPB is an important virulence factor in parasites from the Leishmania (Leishmania mexicana complex: it inhibits lymphocytes Th1 and/or promotes Th2 responses either through proteolytic activity or through epitopes derived from its COOH-terminal extension. In the present study we analyzed the effects of Leishmania (Leishmania amazonensis CPB COOH-terminal extension-derived peptides on cell cultures from murine strains with distinct levels of susceptibility to infection: BALB/c, highly susceptible, and CBA, mildly resistant. Results Predicted epitopes, obtained by in silico mapping, displayed the ability to induce cell proliferation and expression of cytokines related to Th1 and Th2 responses. Furthermore, we applied in silico simulations to investigate how the MHC/epitopes interactions could be related to the immunomodulatory effects on cytokines, finding evidence that specific interaction patterns can be related to in vitro activities. Conclusions Based on our results, we consider that some peptides from the CPB COOH-terminal extension may influence host immune responses in the murine infection, thus helping Leishmania survival.

Pereira Bernardo AS

2011-08-01

117

Genetic diversity of Leishmania amazonensis strains isolated in northeastern Brazil as revealed by DNA sequencing, PCR-based analyses and molecular karyotyping  

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Background Leishmania (Leishmania) amazonensis infection in man results in a clinical spectrum of disease manifestations ranging from cutaneous to mucosal or visceral involvement. In the present study, we have investigated the genetic variability of 18 L. amazonensis strains isolated in northeastern Brazil from patients with different clinical manifestations of leishmaniasis. Parasite DNA was analyzed by sequencing of the ITS flanking the 5.8 S subunit of the ribosomal RNA genes, by RAPD and SSR-PCR and by PFGE followed by hybridization with gene-specific probes. Results ITS sequencing and PCR-based methods revealed genetic heterogeneity among the L. amazonensis isolates examined and molecular karyotyping also showed variation in the chromosome size of different isolates. Unrooted genetic trees separated strains into different groups. Conclusion These results indicate that L. amazonensis strains isolated from leishmaniasis patients from northeastern Brazil are genetically diverse, however, no correlation between genetic polymorphism and phenotype were found. PMID:17584940

de Oliveira, Joao Paulo C; Fernandes, Flora; Cruz, Angela K; Trombela, Viviane; Monteiro, Elisangela; Camargo, Anamaria A; Barral, Aldina; de Oliveira, Camila I

2007-01-01

118

The in vitro biological activity of the Brazilian brown seaweed Dictyota mertensii against Leishmania amazonensis.  

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Seaweeds present a wide variety of interesting bioactive molecules. In the present work we evaluated the biological activity of the dichloromethane/methanol (2:1) extract (DME) from the brown seaweed Dictyota mertensii against Leishmania amazonensis and its cytotoxic potential on mammalian cells. The extract showed significant inhibitory effect on the growth of promastigote forms (IC50=71.60 ?g/mL) and low toxicity against mammalian cells (CC50=233.10 ?g/mL). The DME was also efficient in inhibiting the infection in macrophages, with CC50 of 81.4 ?g/mL and significantly decreased the survival of amastigote forms within these cells. The selectivity index showed that DME was more toxic to both promastigote (SI=3.25) and amastigote (SI=2.86) forms than to macrophages. Increased NO production was observed in treated macrophages suggesting that besides acting directly on the parasites, the DME also shows an immunomodulatory effect on macrophages. Drastic ultrastructural alterations consistent with loss of viability and cell death were observed in treated parasites. Confocal microscopy and cytometry analyzes showed no significant impairment of plasma membrane integrity, whereas an intense depolarization of mitochondrial membrane could be observed by using propidium iodide and rhodamine 123 staining, respectively. The low toxicity to mammalian cells and the effective activity against promastigotes and amastigotes, point to the use of DME as a promising agent for the treatment of cutaneous leishmaniasis. PMID:25207712

dos Santos Aliança, Amanda Silva; dos Anjos, Keicyanne Fernanda Lessa; de Vasconcelos Reis, Thiago Nogueira; Higino, Taciana Mirely Maciel; Brelaz-de-Castro, Maria Carolina Accioly; Bianco, Éverson Miguel; de Figueiredo, Regina Celia Bressan Queiroz

2014-01-01

119

In vitro and in vivo activity of major constituents from Pluchea carolinensis against Leishmania amazonensis.  

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The search for new therapeutic agents from natural sources has been a constant for the treatment of diseases such as leishmaniasis. Herein, in vitro and in vivo pharmacological activities of pure major phenolic constituents (caffeic acid, chlorogenic acid, ferulic acid, quercetin, and rosmarinic acid) from Pluchea carolinensis against Leishmania amazonensis are presented. Pure compounds showed inhibitory activity against promastigotes (IC50?=?0.2-0.9 ?g/mL) and intracellular amastigotes (IC50?=?1.3-2.9 ?g/mL). Four of them were selected after testing against macrophages of BALB/c mice: caffeic acid, ferulic acid, quercetin, and rosmarinic acid, with selective indices of 11, 17, 10, and 20, respectively. Ferulic acid, rosmarinic acid, and caffeic acid controlled lesion size development and parasite burden in footpads from BALB/c experimentally infected mice, after five injections of compounds by intralesional route at 30 mg/kg every 4 days. Pure compounds from P. carolinensis demonstrated antileishmanial properties. PMID:24906989

Montrieux, Elly; Perera, Wilmer H; García, Marley; Maes, Louis; Cos, Paul; Monzote, Lianet

2014-08-01

120

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

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

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

2005-03-01

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

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

Patrícia Shima Luize

2005-03-01

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

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

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

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

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

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

2005-03-01

124

Expression and size heterogeneity of a 63 kilodalton membrane glycoprotein during growth and transformation of Leishmania mexicana amazonensis.  

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Our previous work by immunoprecipitation with a specific monoclonal antibody showed multiple, closely apposed electrophoretic bands of a major surface antigen specific to the promastigote stage of Leishmania mexicana amazonensis. Here, we analyzed the antigen during growth and transformation of this parasite with particular emphasis on the origin of the multiple bands. Immunobinding assays revealed the presence of the antigen throughout all phases of growth of cloned and uncloned promastigotes in various media for different number of generations. More antigen is expressed by promastigotes grown in Medium 199 plus fetal bovine serum than those in serum-supplemented Schneider's medium or a defined medium; however, this is clone-dependent. Purified monoclonal antibody coupled to Affi-Gel 10 gave a high capacity of antigen binding, resolving four electrophoretic bands of 60-66 kDa. A 63 kDa membrane protein, representing one of the four bands, became predominant after [35S]methionine label and chase. Pretreatment of promastigotes with 10 micrograms ml-1 tunicamycin reduces the antigen to a single band of 54 kDa. Treatment of the antigen bound to the affinity gel with endoglycosidase-H produces similar, but less complete effect. These results indicate glycosylation of this antigen with asparagine-linked oligosaccharides, which appears to account at least in part for its expression as multiple, closely apposed bands during biosynthesis. Binding of fluorescein isothiocyanate-labeled 6H12 monoclonal IgG or Fab to the promastigotes showed an even distribution of the antigen over the cell surface and its capping upon the addition of rabbit anti-mouse IgG. Additional hybridomas prepared against amastigotes yielded monoclonal antibodies which recognized surface antigens common to both stages of the parasite. PMID:3515177

Chang, C S; Inserra, T J; Kink, J A; Fong, D; Chang, K P

1986-02-01

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

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

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

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

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

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

2005-08-01

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

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

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

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Tunicamycin-resistant Leishmania mexicana amazonensis: expression of virulence associated with an increased activity of N-acetylglucosaminyltransferase and amplification of its presumptive gene.  

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Tunicamycin at 10 micrograms/ml inhibits the growth and infectivity of the parasitic protozoan Leishmania mexicana amazonensis. Tunicamycin-resistant variants of this parasite were produced by gradual acclimatization of cells to increasing concentrations of the drug up to 80 micrograms/ml and a single-step selection of ethyl methanesulfonate-pretreated or differentiating leishmanias with the drug at 10 micrograms/ml. Prolonged exposure to the drug increases stability of drug resistance of tho...

Kink, J. A.; Chang, K. P.

1987-01-01

129

Flagellates in the Malpighian tubules of laboratory-bred Lutzomyia longipalpis fed on a hamster experimentally infected with Leishmania mexicana amazonensis  

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Full Text Available As a preparatory stage for a study aiming at identifying the species and subspecies of local Leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method.Encontramos abundantes promastigotas nos tubos de Malpighi, além do tubo digestivo, em elevada proporção de fêmeas de Lutzomyia longipalpis experimentalmente infectadas em hamster inoculado com Leishmania mexicana amazonensis.

Elizabeth Ferreira Rangel

1985-09-01

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Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis  

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Full Text Available SciELO Brazil | Language: English Abstract in english Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing [...] of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

Mario Gustavo, Mayer; Lucile Maria, Floeter-Winter.

131

Dynamic of the Cellular Immune Response at the Dermal Site of Leishmania (L.) amazonensis and Leishmania (V.) braziliensis Infection in Sapajus apella Primate.  

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The purpose of this study was to characterize the immunopathological response in the skin of S. apella infected with Leishmania (L.) amazonensis and L. (V.) braziliensis parasites, the main causative agents of localized cutaneous leishmaniasis in South America. In infected animals, amastigote forms of L. (L.) amazonensis could be detected till 120 days postinfection (PI), while, in L. (V.) braziliensis infection, parasites could be detected until 180 days PI in the skin sections. CD20(+) cells were detected throughout the experimental time in both groups as well as in CD3(+) cells, which appeared to be activated because high densities of inducible nitric oxide synthase (iNOS(+)) cells were detected at 60 and 90 days PI in both studied groups. After 60 and 120 days PI, decrease in iNOS(+) cells was observed in L. (L.) amazonensis and L. (V.) braziliensis, respectively, which was associated with parasite clearance. Increase in lysozyme(+) cells was observed during the experimental infections, which also can be associated with parasite killing. PMID:25309902

Laurenti, Márcia Dalastra; Passero, Luiz Felipe Domingues; Tomokane, Thaise Yumie; Francesquini, Fernanda de Camargo; Rocha, Mussya Cisotto; Gomes, Claudia Maria de Castro; Corbett, Carlos Eduardo Pereira; Silveira, Fernando Tobias

2014-01-01

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Dynamic of the Cellular Immune Response at the Dermal Site of Leishmania (L.) amazonensis and Leishmania (V.) braziliensis Infection in Sapajus apella Primate  

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The purpose of this study was to characterize the immunopathological response in the skin of S. apella infected with Leishmania (L.) amazonensis and L. (V.) braziliensis parasites, the main causative agents of localized cutaneous leishmaniasis in South America. In infected animals, amastigote forms of L. (L.) amazonensis could be detected till 120 days postinfection (PI), while, in L. (V.) braziliensis infection, parasites could be detected until 180 days PI in the skin sections. CD20+ cells were detected throughout the experimental time in both groups as well as in CD3+ cells, which appeared to be activated because high densities of inducible nitric oxide synthase (iNOS+) cells were detected at 60 and 90 days PI in both studied groups. After 60 and 120 days PI, decrease in iNOS+ cells was observed in L. (L.) amazonensis and L. (V.) braziliensis, respectively, which was associated with parasite clearance. Increase in lysozyme+ cells was observed during the experimental infections, which also can be associated with parasite killing. PMID:25309902

Laurenti, Marcia Dalastra; Passero, Luiz Felipe Domingues; Tomokane, Thaise Yumie; Francesquini, Fernanda de Camargo; Rocha, Mussya Cisotto; Gomes, Claudia Maria de Castro; Corbett, Carlos Eduardo Pereira; Silveira, Fernando Tobias

2014-01-01

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N-Butyl-[1-(4-Methoxy)Phenyl-9H-?-Carboline]-3-Carboxamide Prevents Cytokinesis in Leishmania amazonensis.  

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Leishmaniasis, a complex of diseases caused by protozoa of the genus Leishmania, is endemic in 98 countries, affecting approximately 12 million people worldwide. Current treatments for leishmaniasis have many disadvantages, such as toxicity, high costs, and prolonged treatment, making the development of new treatment alternatives highly relevant. Several studies have verified the antileishmanial activity of ?-carboline compounds. In the present study, we investigated the in vitro antileishmanial activity of N-butyl-[1-(4-methoxy)phenyl-9H-?-carboline]-3-carboxamide (?-CB) against Leishmania amazonensis. The compound was active against promastigote, axenic amastigote, and intracellular amastigote forms of L. amazonensis, exhibiting high selectivity for the parasite. Moreover, ?-CB did not exhibit hemolytic or mutagenic potential. Promastigotes treated with the alkaloid presented rounding of the body cell, cell membrane projections, an increase in the number of promastigotes presenting two flagella, and parasites of abnormal phenotype, with three or more flagella and/or nuclei. Furthermore, we observed an increase in the subpopulation of cells in the G2/M stage of the cell cycle. Altogether, these results suggest that ?-CB likely prevents cytokinesis, although it does not interfere with the duplication of cell structures. We also verified an increase in O2 (·-) production and the accumulation of lipid storage bodies. Cell membrane integrity was maintained, in addition to the absence of phosphatidylserine externalization, DNA fragmentation, and autophagosomes. Although the possibility of an apoptotic process cannot be discarded, ?-CB likely exerts its antileishmanial activity through a cytostatic effect, thus preventing cellular proliferation. PMID:25224005

Stefanello, T F; Panice, M R; Ueda-Nakamura, T; Sarragiotto, M H; Auzély-Velty, R; Nakamura, C V

2014-12-01

134

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

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

Straus A.H.

1997-01-01

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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 Cutaneous leishmaniasis in Amazonia: the first record of a case of cutaneous leishmaniasis caused by two different parasites: Leishmania braziliensis braziliensis and Leishmania mexicana amazonensis  

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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.For the first time, in the Amazon region, a mixed infection of two Leishmania was found in a patient suffering from dermal leishmaniasis. L. mexicana amazonensis was isolated from one lesion and L. braziliensis braziliensis from another. Both parasites were characterized in sandflies, hamsters, in vitro cultures, by their morphology and by isoenzyme studies in starch gel. The Authors conclude that the occurrence of this case combined with the known lack of cross immunity between most leishmanial parasites means that a vaccine for this region must be polyvalent.

F. T. Silveira

1984-10-01

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Treatment with triterpenic fraction purified from Baccharis uncinella leaves inhibits Leishmania (Leishmania) amazonensis spreading and improves Th1 immune response in infected mice.  

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The current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. Therefore, the search for new leishmanicidal compounds is indispensable. Recently, it was demonstrated that oleanolic- and ursolic-containing fraction from Baccharis uncinella leaves eliminated the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and L. (Viannia) braziliensis without causing toxic effects for J774 macrophages. Thus, the aim of the present work was to characterize the therapeutic effect of the triterpenic fraction in L. (L.) amazonensis-infected BALB/c mice. Oleanolic- and ursolic acid-containing fraction was extracted from B. uncinella leaves using organic solvents and chromatographic procedures. L. (L.) amazonensis-infected BALB/c mice were treated intraperitoneally with triterpenic fraction during five consecutive days with 1.0 and 5.0 mg/kg of triterpenic fraction, or with 10.0 mg/kg of amphotericin B drug. Groups of mice treated with the triterpenic fraction, presented with decreased lesion size and low parasitism of the skin-both of which were associated with high amounts of interleukin-12 and interferon gamma. The curative effect of this fraction was similar to amphotericin B-treated mice; however, the final dose, required to eliminate amastigotes, was lesser than amphotericin B. Moreover, triterpenic fraction did not cause microscopic alterations in liver, spleen, heart, lung, and kidney of experimental groups. This work suggests that this fraction possesses compounds that are characterized by leishmanicidal and immunomodulatory activities. From this perspective, the triterpenic fraction can be explored as a new therapeutic agent for use against American Tegumentar Leishmaniasis. PMID:24173812

Yamamoto, Eduardo Seiji; Campos, Bruno Luiz S; Laurenti, Márcia Dalastra; Lago, João H G; Grecco, Simone dos Santos; Corbett, Carlos E P; Passero, Luiz Felipe D

2014-01-01

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Effect of Elatol, Isolated from Red Seaweed Laurencia dendroidea, on Leishmania amazonensis  

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In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson) J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC50 of 4.0 µM and 0.45 µM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control...

Celso Vataru Nakamura; Renato Crespo Pereira; Daniela Bueno Sudatti; Éverson Miguel Bianco; Benedito Prado Dias Filho; Tânia Ueda-Nakamura; Adriana Oliveira dos Santos; Phercyles Veiga-Santos

2010-01-01

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

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

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

2012-05-01

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

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

Denise CS, Matos; Lanuza AP, Faccioli; Léa, Cysne-Finkelstein; Paula Mello De, Luca; Suzana, Corte-Real; Geraldo RG, Armôa; Elezer Monte Blanco, Lemes; Débora, Decote-Ricardo; Sergio CF, Mendonça.

2010-05-01

140

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

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

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

 
 
 
 
141

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

Scientific Electronic Library Online (English)

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

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

2011-02-01

142

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

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

Valderes L de Souza

2011-02-01

143

In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania) amazonensis, L (L.) chagasi and L (Viannia) braziliensis  

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Full Text Available SciELO Brazil | Language: English Abstract in english The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs), was assessed and compared to Glucantime®-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10µg/ml to 300 µg/ml for L. (L [...] .) chagasi and from 50µg/ml to 300µg/ml for L. (L.) amazonensis, with no statistically significant differences among the four batches of TAMs and Glucantime®. The inhibitory concentrations (IC50) determined by the amastigote-infected macrophage model for TAM01/03 and Glucantime® were, respectively: 26.3µg/ml and 127.6µg/ml for L. chagasi, 15.4µg /ml and 22.9µg/ml for L. amazonensis, and 12.1µg/ml and 24.2µg/ml for L. (V.) braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, Glucantime®-Aventis, against three species of Leishmania that are of medical importance in Brazil.

Eliane de, Morais-Teixeira; Alcione S de, Carvalho; Jorge CS da, Costa; Silvio L, Duarte; Jorge S, Mendonça; Núbia, Boechat; Ana, Rabello.

2008-06-01

144

In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania amazonensis, L (L. chagasi and L (Viannia braziliensis  

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Full Text Available The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs, was assessed and compared to Glucantime®-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10µg/ml to 300 µg/ml for L. (L. chagasi and from 50µg/ml to 300µg/ml for L. (L. amazonensis, with no statistically significant differences among the four batches of TAMs and Glucantime®. The inhibitory concentrations (IC50 determined by the amastigote-infected macrophage model for TAM01/03 and Glucantime® were, respectively: 26.3µg/ml and 127.6µg/ml for L. chagasi, 15.4µg /ml and 22.9µg/ml for L. amazonensis, and 12.1µg/ml and 24.2µg/ml for L. (V. braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, Glucantime®-Aventis, against three species of Leishmania that are of medical importance in Brazil.

Eliane de Morais-Teixeira

2008-06-01

145

In vitro and in vivo activity of meglumine antimoniate produced at Farmanguinhos-Fiocruz, Brazil, against Leishmania (Leishmania) amazonensis, L (L.) chagasi and L (Viannia) braziliensis  

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Full Text Available SciELO Brazil | Language: English Abstract in english The leishmanicidal activity of four batches of meglumine antimoniate, produced in Farmanguinhos-Fiocruz, Brazil (TAMs), was assessed and compared to Glucantime®-Aventis Pharma Ltda. Using the amastigote-like in vitro model, the active concentrations of Sb v varied from 10µg/ml to 300 µg/ml for L. (L [...] .) chagasi and from 50µg/ml to 300µg/ml for L. (L.) amazonensis, with no statistically significant differences among the four batches of TAMs and Glucantime®. The inhibitory concentrations (IC50) determined by the amastigote-infected macrophage model for TAM01/03 and Glucantime® were, respectively: 26.3µg/ml and 127.6µg/ml for L. chagasi, 15.4µg /ml and 22.9µg/ml for L. amazonensis, and 12.1µg/ml and 24.2µg/ml for L. (V.) braziliensis. The activities of the four batches of TAMs were confirmed in an in vivo model by assessing, during eight weeks skin lesions caused by L. braziliensis in hamster that were treated with 20mg Sb v/Kg/day for 30 consecutive days. The meglumine antimoniate produced by Farmanguinhos was as effective as the reference drug, Glucantime®-Aventis, against three species of Leishmania that are of medical importance in Brazil.

Eliane de, Morais-Teixeira; Alcione S de, Carvalho; Jorge CS da, Costa; Silvio L, Duarte; Jorge S, Mendonça; Núbia, Boechat; Ana, Rabello.

146

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

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

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

2014-10-01

147

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

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

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

2013-02-01

148

Flagellates in the Malpighian tubules of laboratory-bred Lutzomyia longipalpis fed on a hamster experimentally infected with Leishmania mexicana amazonensis  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Encontramos abundantes promastigotas nos tubos de Malpighi, além do tubo digestivo, em elevada proporção de fêmeas de Lutzomyia longipalpis experimentalmente infectadas em hamster inoculado com Leishmania mexicana amazonensis. [...] Abstract in english As a preparatory stage for a study aiming at identifying the species and subspecies of local Leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, [...] in order to test the effectiveness of the method.

Elizabeth Ferreira, Rangel; Leonidas M., Deane; Gabriel, Grimaldi Filho; Nataly A. de, Souza; Eduardo D., Wermelinger; André F., Barbosa.

149

Inhibition of Leishmania (Leishmania) amazonensis and Rat Arginases by Green Tea EGCG, (+)-Catechin and (-)-Epicatechin: A Comparative Structural Analysis of Enzyme-Inhibitor Interactions  

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Epigallocatechin-3-gallate (EGCG), a dietary polyphenol (flavanol) from green tea, possesses leishmanicidal and antitrypanosomal activity. Mitochondrial damage was observed in Leishmania treated with EGCG, and it contributed to the lethal effect. However, the molecular target has not been defined. In this study, EGCG, (+)-catechin and (?)-epicatechin were tested against recombinant arginase from Leishmania amazonensis (ARG-L) and rat liver arginase (ARG-1). The compounds inhibit ARG-L and ARG-1 but are more active against the parasite enzyme. Enzyme kinetics reveal that EGCG is a mixed inhibitor of the ARG-L while (+)-catechin and (?)-epicatechin are competitive inhibitors. The most potent arginase inhibitor is (+)-catechin (IC50?=?0.8 µM) followed by (?)-epicatechin (IC50?=?1.8 µM), gallic acid (IC50?=?2.2 µM) and EGCG (IC50?=?3.8 µM). Docking analyses showed different modes of interaction of the compounds with the active sites of ARG-L and ARG-1. Due to the low IC50 values obtained for ARG-L, flavanols can be used as a supplement for leishmaniasis treatment. PMID:24260115

dos Reis, Matheus Balduino Goncalves; Manjolin, Leticia Correa; Maquiaveli, Claudia do Carmo; Santos-Filho, Osvaldo Andrade; da Silva, Edson Roberto

2013-01-01

150

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

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Full Text Available A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzomyia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas.

R. A. Freitas

1989-09-01

151

Leishmania mexicana amazonensis: development of a peptide tag useful for labeling and purifying biotinylated recombinant proteins.  

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A number of peptide tags are available to facilitate the characterization of recombinant proteins. We have tested the bacterial oxaloacetate decarboxylase biotinylation domain for its efficacy in tagging recombinant proteins in vivo in Leishmania. To achieve efficient biotinylation, Leishmania also had to be co-transformed with the gene for bacterial biotin protein ligase (birA gene product). The recombinant chimeric protein could be detected on blots probed with avidin-horseradish peroxidase and purified on immobilized monomeric avidin resins. PMID:17027004

Detke, Siegfried

2007-03-01

152

Leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps  

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Neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and NETosis. Upon death by NETosis, neutrophils release fibrous traps of DNA, histones, and granule proteins named neutrophil extracellular traps (NETs), which can kill bacteria and fungi. Inoculation of the protozoan Leishmania into the mammalian skin causes local inflammation with neutrophil recruitment. Here, we investigated the release of NETs by human neutrophils upon their interaction with Leishmania parasites and N...

Guimara?es-costa, Anderson B.; Nascimento, Michelle T. C.; Froment, Giselle S.; Soares, Rodrigo P. P.; Morgado, Fernanda N.; Conceic?a?o-silva, Fa?tima; Saraiva, Elvira M.

2009-01-01

153

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

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

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

154

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

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

Silva-Jr FP

2002-01-01

155

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

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

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

2002-04-01

156

Papel de la vacuola parasitófora de macrófagos de ratón infectados por Leishmania amazonensis en la adquisición de moléculas / Role of the parasitophorous vacuole of murine macrophages infected with Leishmania amazonensis in molecule acquisition  

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Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Introducción. Leishmania son parásitos intracelulares de macrófagos, confinados en compartimentos denominados vacuolas parasitóforas. La permeabilidad de este compartimento depende de su interacción con el tráfico vesicular y transportadores presentes en su membrana. Objetivo. En este trabajo se est [...] udió la permeabilidad de la membrana de la vacuola parasitófora en la línea celular J774.A1 infectada con Leishmania amazonensis, in situ y en compartimentos aislados. Materiales y métodos. El aislamiento de vacuolas parasitóforas se hizo por gradiente de densidad. La permeabilidad de la membrana de estas se valoró por distribución de sondas fluorescentes y electrofisiología. Para establecer indirectamente el transporte de protones se usó naranja de acridina. La presencia de transportadores ABC sensibles a probenecid se estableció con amarillo lucifer y calceína. Por primera vez con la técnica de patch-clamp se registraron corrientes en la membrana de este compartimento aislado. Resultados. La vacuola parasitófora colorea de rojo con naranja de acridina indicando un pH ácido. Concentra amarillo lucifer a través de un transportador sensible a probenecid, pero excluye la sonda calceína. Vacuolas aisladas se marcan de rojo con naranja de acridina y concentran amarillo lucifer a través de un transportador sensible a probenecid. Estas vacuolas excluyeron calceína y presentaron en su membrana una corriente iónica que se activa a diferencias de potencial cercanas a 60 mV, con una conductancia de 46 ± 3 pS. Conclusiones. Se pueden aislar vacuolas parasitóforas con propiedades de permeabilidad que preservan mecanismos de transporte similares a los encontrados in situ. Se registra por primera vez la presencia de una corriente iónica poco selectiva en la membrana de este compartimiento. Abstract in english Introduction. Leishmania are intracellular parasites of macrophages, confined into compartments known as parasitophorous vacuoles. The permeability of this compartment depends on its interaction with the endocytic pathway and transport proteins present on its membrane. Objective. The membrane permea [...] bility of the parasitophorous vacuole was studied in J774.A1- macrophage like cells infected with Leishmania amazonensis, in situ and on isolated compartments. Materials and methods. The parasitophorous vacuoles were isolated by density gradients. Fluorescent probe distribution and electrophysiological recordings were used to determine parasitophorous vacuole membrane permeability. Proton transport was evaluated indirectly by acridine orange staining. Probenecid sensitive ABC transporters were detected using the fluorescent probes lucifer yellow and calcein. For the first time ion currents were recorded on the membrane of isolated parasitophorous vacuoles using the patch clamp technique. Results. The parasitophorous vacuole stains red with acridine orange indicating an acidic compartment. It concentrates lucifer yellow by means of a probenecid sensitive transporter but excludes calcein. Isolated vacuoles stained red with acridine orange and concentrated lucifer yellow by means of a probenecid sensitive transporter. These vacuoles excluded calcein and showed an ion current in their membrane which is activated at potentials close to 60 mV with a mean conductance of 46 ± 3 pS. Conclusions. Isolated parasitophorous vacuoles with permeability properties preserving transport mechanisms similar to those found in situ can be purified. A poorly selective ion current on the parasitophorous vacuole membrane is reported for the first time.

Tania M, Cortázar; Joselín, Hernández; María Clara, Echeverry; Marcela, Camacho.

157

Chronic inflammatory response modulation against Leishmania (L. amazonensis by homeopathic thymulin and antimonium crudum inBalb/c mice  

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Full Text Available In previous studies it was found that thymulin 5cH (thymic hormone can modulate immune processes in several diseases. Additionally, the Antimonium crudum has used in dogs bearing leishmaniosis, according to the similia principle. We studied the inflammatory and immune modulation by thymulin 5CH and Antimonium crudum 30CH treatment in mice experimentally inoculated with Leishmania (L. amazonensis. Male adult Balb/c mice were inoculated with Leishmania (2x105 promastigotes into the footpad to induce inflammatory response and peritoneum and spleen cells were evaluated by flow cytometry after 60 days. Animals were divided in 3 groups (n=10: thymulin 5cH, Antimonium crudum 30cH and vehicle /control. Treatment was made in blind, daily, in water/alcohol 30% diluted 1:2500 in drinking water, during all experimental period. CD11b (activated phagocytes and B1 cells, CD19 (B1 cells and B2, CD4 and CD8 (effective T lymphocytes markers were used to identify immune cells subsets in peritoneal washing fluid and spleen cell suspension. Mice treated with thymulin 5cH presented increase in peritoneal and spleen B1 stem cells (X2=0.0001 and higher CD8+/CD4+ ratio in spleen, regarding to the control. Also, Antimonium crudum 30CH induced a mild increase in B1 cells in peritoneum and spleen ( both X2, p=0.0001. Further histological analysis of the primary lesion will be done in the next step, to elucidate the impact of these findings in the disease evolution. The results show that both treatments stimulate B1 stem cell proliferation and suggest the cooperation of T spleen lymphocytes in the process.

Leoni Villano Bonamin

2012-09-01

158

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

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Leishmania (Leishmania) amazonensis exhibits peculiarities in its interactions with hosts. Because amastigotes are the primary form associated with the progression of infection, we studied the effect of insulin-like growth factor (IGF)-I on interactions between L. (L.) amazonensis amastigotes and macrophages. Upon stimulation of infected macrophages with IGF-I, we observed decreased nitric oxide production but increased arginase expression and activity, which lead to increased parasitism. However, stimulation of amastigote-infected macrophages with IGF-I did not result in altered cytokine levels compared to unstimulated controls. Because IGF-I is present in tissue fluids and also within macrophages, we examined the possible effect of this factor on phosphatidylserine (PS) exposure on amastigotes, seen previously in tissue-derived amastigotes leading to increased parasitism. Stimulation with IGF-I induced PS exposure on amastigotes but not on promastigotes. Using a PS-liposome instead of amastigotes, we observed that the PS-liposome but not the control phosphatidylcholine-liposome led to increased arginase activity in macrophages, and this process was not blocked by anti-TGF-? antibodies. Our results suggest that in L. (L.) amazonensis amastigote-infected macrophages, IGF-I induces arginase activity directly in amastigotes and in macrophages through the induction of PS exposure on amastigotes in the latter, which could lead to the alternative activation of macrophages through cytokine-independent mechanisms. PMID:25294956

Vendrame, Celia Maria Vieira; Carvalho, Marcia Dias Teixeira; Tempone, Andre Gustavo

2014-01-01

159

Effect of Elatol, Isolated from Red Seaweed Laurencia dendroidea, on Leishmania amazonensis  

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Full Text Available In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC50 of 4.0 µM and 0.45 µM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cells, including: pronounced swelling of the mitochondrion; appearance of concentric membrane structures inside the organelle; destabilization of the plasma membrane; and formation of membrane structures, apparently an extension of the endoplasmic reticulum, which is suggestive of an autophagic process. A cytotoxicity assay showed that the action of the isolated compound is more specific for protozoa, and it is not toxic to macrophages. Our studies indicated that elatol is a potent antiproliferative agent against promastigote and intracellular amastigote forms, and may have important advantages for the development of new anti-leishamanial chemotherapies.

Celso Vataru Nakamura

2010-10-01

160

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

Scientific Electronic Library Online (English)

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

Kátia da Silva, Calabrese; Sylvio Celso Gonçalves da, Costa.

 
 
 
 
161

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

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

Kátia da Silva Calabrese

1992-01-01

162

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

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

Jose M. Requena

2008-04-01

163

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

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Abstract Leishmania is inoculated, by the bite of an infected sandfly, into the skin of the host, where the promastigotes are phagocyted by dermal macrophages. The dermal region comprises cells and abundant extracellular matrix. Studies show that matrix metalloproteinases play an important role in host defense responses against pathogens in mammals and that their activities lead to the production of antimicrobial peptides. The aim of this study is to evaluate the changes in...

Silva-Almeida Mariana; Sf, Souza Celeste; Hardoim Daiana J

2012-01-01

164

Dolabelladienetriol, a Compound from Dictyota pfaffii Algae, Inhibits the Infection by Leishmania amazonensis  

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Leishmaniasis is a global disease, which is treated with expensive compounds. Anti-leishmaniasis therapy causes severe side effects, and parasite resistance is often observed, which highlights the importance of discovering new drugs against its causal agent, the protozoan parasite Leishmania. Recently, the geographical overlapping distribution of leishmaniasis and the infection by the human immunodeficiency virus type 1 (HIV-1) has contributed to a dramatic increase in the number of individua...

Soares, Deivid Costa; Calegari-silva, Teresa C.; Lopes, Ulisses G.; Teixeira, Vale?ria L.; Palmer Paixa?o, Izabel C. N.; Cirne-santos, Claudio; Bou-habib, Dumith Chequer; Saraiva, Elvira M.

2012-01-01

165

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

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

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

2010-10-01

166

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

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

Zirlane Castelo B Coêlho

2010-10-01

167

Low-Dose UVB Contributes to Host Resistance against Leishmania amazonensis Infection in Mice through Induction of Gamma Interferon and Tumor Necrosis Factor Alpha Cytokines  

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UV radiation suppresses the immune response, a fact which raises the question of whether the phenomenon may find practical applications in the outcome of infectious diseases. In this study, BALB/c mice were exposed to low-dose UVB (250 J/m2) from Dermaray M-DMR-100 for 4 consecutive days. Twelve hours after the last UV exposure, groups of mice were injected with 2 × 106 Leishmania amazonensis promastigotes. The development of skin lesions, as assessed by measurement of visible cutaneous lesi...

Khaskhely, Noor Mohammad; Maruno, Motoyoshi; Uezato, Hiroshi; Takamiyagi, Atsushi; Ramzi, Saeef Taher; Kasem, Khan Mohammad Al; Kariya, Ken-ichi; Toda, Takayoshi; Hashiguchi, Yoshihisa; Landires, Eduardo A. Gomez; Nonaka, Shigeo

2002-01-01

168

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

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

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

2007-02-01

169

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

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

Fernando T. Silveira

1989-09-01

170

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzo [...] myia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas. Abstract in english A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazi [...] l, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.

R. A., Freitas; T. V., Barrett; R. D., Naiff.

171

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Um flebotomíneo do complexo Lutzomyia flaviscutellata, de Rondônia e sul do Amazonas, Brasil é tão parecido com Lutzomyia olmeca reducta, que é considerado como sendo da mesma espécie. Este flebotomíneo ocorre junto com L. olmeca nociva, portanto o nome é emendado para o nível de espécie, como Lutzo [...] myia reducta. O material do Brasil é descrito e ilustrado, e comparado com exemplares de L. o. nociva e L. flaviscutellata da mesma área. Chaves para as espécies e subespécies do complexo flaviscutellata são incluídas. Leishmania amazonensis foi isolada em um exemplar de L. reducta altamente infectado, tornando esta espécie a terceira a ser implicada como vetor desta leishmania no Brasil. A abundância relativa das três espécies simpátricas do complexo flaviscutellata varia em escala local e aparenta ter relação com a drenagem do solo. L. reducta constituiu cerca de 25% dos flebotomíneos capturados em armadilhas Disney em locais mal e bem drenados, porém não foi encontrada em locais sujeitos a inundações. L. olmeca nociva era restrita às áreas mal drenadas não sujeitas a inundações, enquanto L. flaviscutellata foi capturada neste dois ambientes e também numa área periodicamente inundada. L. reducta não tem sido assinalada ao norte do Rio Amazonas no Brasil, porém a ausência de registros do oeste e noroeste do Estado do Amazonas possa refletri a falta de levantamento nestas áreas. Abstract in english A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazi [...] l, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.

R. A., Freitas; T. V., Barrett; R. D., Naiff.

1989-09-01

172

Identification of a transcription factor like protein at the TOR locus in Leishmania mexicana amazonensis.  

Science.gov (United States)

The TOR gene (TOxic nucleoside Resistance gene) was mapped to a 2.3 kb fragment on the amplified DNA from tubercidin resistant Leishmania (TUB). This DNA fragment conferred upon wild type cells resistance to tubercidin, inosine dialdehyde, formycin A and B and allopurinol riboside and a reduced ability to accumulate purine nucleobases and nucleosides. These properties were characteristic of the parental TUB cells which carried the intact amplified DNA and have been hypothesized to be caused by a reduction in the activity of the multiple purine transporters within this organism. The TOR gene was found to be partially homologous to the rodent and human Oct-6/SCIP/Tst-1 gene. It lacked, however, the POU specific domain of this class of transcription factors and contained only the first two helices of the POU homeodomain. This truncated homeodomain was not required to confer resistance upon wild type cells to toxic nucleosides, suggesting that TOR was not a repressor with independent DNA binding capability. PMID:9476797

Detke, S

1997-12-15

173

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

Science.gov (United States)

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

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

2006-08-01

174

Short-term protection conferred by Leishvacin® against experimental Leishmania amazonensis infection in C57BL/6 mice.  

Science.gov (United States)

To date, there is no vaccine available against human leishmaniasis. Although some vaccination protocols can induce immunity in murine models, they fail to induce protection in humans. The reasons for that remain unclear. The aim of the present study was to characterize the changes in the pattern of the immune response during subcutaneous vaccination with Leishvacin® in mice. We also investigated whether IFN-? and nitric oxide synthase are indispensable for the protection elicited by the vaccine. C57BL/6 WT vaccinated mice showed smaller lesions and fewer numbers of parasites in footpads until 8 weeks post-infection. Up to this time, they produced higher levels of IFN-?, IL-2, IL-4, IL-17A and IL-10 and higher specific antibody response than control non-vaccinated mice. Moreover, we showed that IFN-?, most likely by induction of iNOS expression, is essential for immunity. However, after 12 weeks of infection, we observed loss of difference in lesion size and parasite burden between the groups. Loss of resistance was associated with the disappearance of differences in cytokine patterns between vaccinated and control mice, but not of antibody response, which remained different until a later time of infection. The reversal of resistance to L. amazonensis could not be explained by upregulation of regulatory cytokines. Our data point to a subversion of the host immune response by L. amazonensis even when a protective response was previously induced. PMID:25102355

Carneiro, Matheus Batista Heitor; de Andrade e Sousa, Louisa Maria; Vaz, Leonardo Gomes; Dos Santos, Liliane Martins; Vilela, Luciano; de Souza, Carolina Carvalho; Gonçalves, Ricardo; Tafuri, Wagner Luis; Afonso, Luís Carlos Crocco; Côrtes, Denise Fonseca; Vieira, Leda Quercia

2014-12-01

175

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

Science.gov (United States)

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

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

2012-08-01

176

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

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

2007-01-01

177

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

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

José F. Gil

2011-10-01

178

Reduced purine accumulation is encoded on an amplified DNA in Leishmania mexicana amazonensis resistant to toxic nucleosides.  

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Nucleoside analogs are potential anti-Leishmania agents. To better understand how these compounds might lose their effectiveness, Leishmania were independently selected for resistance to inosine dialdehyde or tubercidin. Each of the resistant cells exhibited resistance to inosine dialdehyde and tubercidin as well as to formycin B and allopurinol ribonucleoside. Resistant cells had a greatly reduced capability of accumulating exogenous adenosine, guanosine, thymidine and guanine. This decreased ability to accumulate nucleosides and at least one nucleobase appeared to be due to reduced activity of a number of distinct purine transporters, as the differences between purine metabolizing enzymes were not sufficiently different to account for the decreased accumulation capability. The resistance to toxic nucleosides and the decreased ability to accumulate purines were due to the presence in the resistant cells of an extrachromosomal DNA approximately 55 kb in size. The extrachromosomal DNA was not detected in wild-type cells or revertants which have lost resistance to toxic nucleosides. Except for a 1.2-kb difference, the extrachromosomal DNA from both independently selected resistant cells appeared to be identical. The resistant cells contained 2-4 times as much DNA homologous to the extrachromosomal DNA as compared to wild type cells. When cloned into an E. coli/Leishmania shuttle vector, a portion of the amplified DNA had the ability to confer upon wild-type cells resistance to the toxic purine nucleoside analogs tubercidin and inosine dialdehyde. These transformed cells also exhibited a decreased ability to accumulate non-toxic purine nucleosides. PMID:8232410

Kerby, B R; Detke, S

1993-08-01

179

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

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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%), ? -elemene (14.25%), and trans- ? -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04? ? g·mL(-1)) and amastigotes (IC50, 1.92? ? 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? ? g·mL(-1)); however, there appeared to be no toxicity at 50? ? 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. PMID:23533469

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

180

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

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

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

 
 
 
 
181

Leishmaniasis in Brazil: XX. Prevalence of "enzootic rodent leishmaniasis" (Leishmania mexicana amazonensis), and apparent absence of "pian bois" (Le. braziliensis guyanensis), in plantations of introduced tree species and in other non-climax forests in eastern Amazônia.  

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In Amazonian Brazil most human leishmaniasis is due to Leishmania braziliensis s.l. and is acquired during the clearing of primary climax forest. One of the largest deforestation projects has taken place on the JARI property where plantations of exotic tree species are grown for paper pulp. The ability of the regional leishmaniasis enzootics to invade plantations was investigated. CDC light-trap catches indicated the phletobomine vectors of Le. b. guyanensis (causing "pian bois" in man) to be very scarce in JARI plantations compared to native-forest controls. It is concluded (drawing on other observations) that the vectors of "pian bois" are unlikely to thrive in any secondary forest. In contrast, catches from mammal traps and rodent-baited (Disney) traps demonstrated the presence in JARI plantations of infected Proechimys guyannensis and large populations of Lutzomyia flaviscutellata, respectively the major rodent reservoir and sandfly vector of Le. mexicana amazonensis. Alone amongst the local vectors of human cutaneous leishmaniasis, Lu. flaviscutellata is adapted to non-climax forests (primary or secondary, natural or man-made; synopsis given). It is predicted that the public health importance of Le. m. amazonensis is unlikely to diminish following the development of Amazônia. This is worrying because ca. 30% of Le. m. amazonensis infections in man cause highly-disfiguring, incurable "diffuse cutaneous leishmaniasis". PMID:6665830

Ready, P D; Lainson, R; Shaw, J J

1983-01-01

182

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

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

Camargo Jiménez Maria Helena

2000-06-01

183

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

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

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

184

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

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

Ednelza de Almeida Benicio

2011-12-01

185

Serine protease activities in Leishmania (Leishmania) chagasi promastigotes.  

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The present work reports the isolation, biochemical characterization, and subcellular location of serine proteases from aqueous, detergent soluble, and culture supernatant of Leishmania chagasi promastigote extracts, respectively, LCSII, LCSI, and LCSIII. The active enzyme molecular masses of LCSII were about 105, 66, and 60 kDa; of LCSI, 60 and 58 kDa; and of LCSIII, approximately 76 and 68 kDa. Optimal pH for the enzymes was 7.0 for LCSI and LCSIII and 8.5 for LCSII, and the optimal temperature for all enzymes was 37°C, using ?-N-?-tosyl-L: -arginine methyl ester as substrate. Assay of thermal stability indicated that LCSIII is the more stable enzyme. Hemoglobin, bovine serum albumin, and ovalbumin were hydrolyzed by LCSII and LCSI but not by LCSIII. Inhibition studies suggested that enzymes belong to the serine protease class modulated by divalent cations. Rabbit antiserum against 56-kDa serine protease of Leishmania amazonensis identified proteins in all extracts of L. chagasi. Furthermore, immunocytochemistry demonstrated that serine proteases are located in flagellar pocket region and cytoplasmic vesicles of L. chagasi promastigotes. These findings indicate that L. chagasi serine proteases differ from L. amazonensis proteases and all known flagellate proteases, but display some similarities with serine proteases from other Leishmania species, suggesting a conservation of this enzymatic activity in the genus. PMID:20668879

da Silva-López, Raquel Elisa; dos Santos, Tatiana Resende; Morgado-Díaz, José Andrés; Tanaka, Marcelo Neves; de Simone, Salvatore Giovanni

2010-10-01

186

Antigenic extracts of Leishmania braziliensis and Leishmania amazonensis associated with saponin partially protects BALB/c mice against Leishmania chagasi infection by suppressing IL-10 and IL-4 production  

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Full Text Available SciELO Brazil | Language: English Abstract in english This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishmania chagasiinfection. These immunogenic preparations were composed of Leishmania amazonensisor Leishmania braziliensisantigenic extracts in association with saponin adjuvant. Mice were given [...] three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasiby intravenous injection. We observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensisantigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasiantigen. No change was detected in the production of IFN-?. Our data show that these immunogenic preparations reduce the type 2 immune response leading to the control of parasite replication.

Rafaella FQ, Grenfell; Eduardo A, Marques-da-Silva; Miriam C, Souza-Testasicca; Eduardo AF, Coelho; Ana Paula, Fernandes; Luís Carlos C, Afonso; Simone A, Rezende.

187

Métodos subsidiários para o diagnóstico da Leishmaniose tegumentar americana (LTA: comparação dos resultados do seqüenciamento de DNA e da PCR-RFLP para determinação da espécie de leishmania em amostras cutâneo-mucosas Subsidiary methods for the diagnosis of American tegumentar leishmaniasis (ATL: comparison of sequencing of DNA and PCR-RFLP for identification of leishmania species in skin samples  

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Full Text Available FUNDAMENTOS: Métodos moleculares têm-se mostrados mais eficazes para o diagnóstico da LTA. OBJETIVOS: Comparar os resultados da intradermorreação de Montenegro (IRM, presença de leishmania em biópsia (Bc, reação de imunofluorescência indireta (Rifi, seqüenciamento de DNA e PCR-RFLP (-restriction fragment lenght polymorphism para o diagnóstico da LTA. MÉTODOS: Foram estudados 152 pacientes com LTA. Para a PCR em Bc, utilizaram-se primers específicos para seqüência de 120bp do kDNA do minicírculo comum a todas as espécies de leishmanias. O produto da PCR, utilizado para seqüenciamento e para restrição enzimática com Hae III, foi comparado às culturas L. (L. amazonensis e L. (V. braziliensis. RESULTADOS: Houve predomínio do sexo masculino (75%, da cor branca (80% e da profissão urbana (48%. A idade variou de três a 77 anos, com 56,5% entre 21 e 50 anos. 65,8% eram do Estado de São Paulo, prevalecendo a forma cutânea (79,6%. A IRM foi positiva em 73,4%, e a Rifi em 59,7%, enquanto a Bc evidenciou presença de leishmania em 30,6%. A PCR foi positiva em 81,6%, e a PCR-RFLP identificou L. (V. braziliensis como espécie predominante (66%, o que também ocorreu com o seqüenciamento. Comparando PCR-RFLP e seqüenciamento, houve 61% de concordância entre os resultados, mostrando significância da PCR-RFLP para L. (V. braziliensis. CONCLUSÕES: A IRM e a PCR foram estatisticamente equivalentes como métodos subsidiários para o diagnóstico da LTA, a PCR-RFLP e o seqüenciamento também o foram na identificação das espécies de leishmania, o primeiro apresentando menores custo e tempo de execução comparado ao seqüenciamento de DNA.BACKGROUND: ATL is endemic in Brazil, and molecular methods have been shown more effective for its diagnosis. OBJECTIVES: Our purpose was to compare the results of Montenegro’s skin reaction (MR, presence of leishmania in skin biopsy (Bx, indirect immunofluorescence (IIF for leishmania in sera samples, PCR, sequencing of DNA and PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism as subsidiary exams for ATL diagnose. METHODS: 152 patients were studied, with accomplishment of MR, Bx, IIF and PCR for leishmania in skin samples. For PCR, a specific pair of primers for a sequence of 120bp from kDNA minicircle, common to all leishmanias species, was used. The product of PCR was used for DNA sequencing and for RFLP with the enzyme Hae III. The analysis of the restriction pattern was compared to the cultures of L. (L. amazonensis and L. (V. braziliensis. RESULTS: The predominant sex was male (75%, the white color (80% and urban professional occupation (48%. The age varied from 3 to 77 years, with prevalence from 21 to 50 years (56.5%. In relation to the origin, 65.8% was from the state of São Paulo, being the cutaneous form the more prevalent (79.6%. MR was positive in 73.4% and there was presence of leishmania in 30.6% of the samples, while IIF presented 59.7% of positivity. PCR was positive in 81.6% of skin samples, and PCR-RFLP identified L. (V. braziliensis (66% as predominant species, fact that also happened with DNA sequencing, with 64.4% of the positive results for L. (V. braziliensis. Comparing PCR-RFLP and DNA sequencing there was 61% of agreement amongst the results, being significant in PCR-RFLP for L. (V. braziliensis. CONCLUSION: MR and PCR were equivalent as subsidiary methods for the diagnosis of ATL, such as PCR-RFLP and DNA sequencing in the identification of the leishmania species. On the other hand, the method PCR-RFLP presented smaller cost and smaller time of execution compared to the sequencing of DNA.

Flávio C. Barbosa Garcia

2005-12-01

188

Activity, toxicity and analysis of resistance of essential oil from Chenopodium ambrosioides after intraperitoneal, oral and intralesional administration in BALB/c mice infected with Leishmania amazonensis: a preliminary study.  

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The World Health Organization has classified the leishmaniasis as a major tropical disease. Current therapy is toxic, expensive and cause several adverse effects. The majority of people in endemic areas of leishmaniasis depend of natural and traditional medicine. This study was developed to examine the activity of the essential oil from Chenopodium ambrosioides in BALB/c mice infected with Leishmania amazonensis. The infected animals received two cycle of treatment by different routes (intraperitoneal, oral or intralesional route). The intraperitoneal administration of the essential oil at dose of 30 mg/Kg prevented lesion development and decrease the parasite burden. Oral administration retarded the infection in the experimental model compared with untreated mice, although it was less effective that the intraperitoneal route. The administration by intralesional route did not show activity. Intraperitoneal and oral treatment at 30 mg/Kg with the essential oil had better antileishmanial effect that treatment with the reference drug, amphotericin B at 1 mg/Kg. Preliminarily, we examined the toxicity and the resistance after treatment. Signs of toxicity were evident only in the animals treated by intraperitoneal route. No resistance was detected in L. amazonensis isolates obtained from treated mice. These data clearly demonstrated that this natural product could be an alternative for the development of a new drug against cutaneous leishmaniasis based in the ethnomedical information. PMID:17254746

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

2007-01-01

189

The in vitro leishmanicidal activity of hexadecylphosphocholine (miltefosine) against four medically relevant Leishmania species of Brazil  

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The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH) was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) chagasi. The activity of miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania) donovani, which is known to be sensitive to the effects of miltefosi...

Eliane de Morais-Teixeira; Quesia Souza Damasceno; Mariana Kolos Galuppo; Alvaro José Romanha; Ana Rabello

2011-01-01

190

Leishmaniose cutânea disseminada produzida por Leishmania viannia braziliensis no Estado do Maranhão - Brasil  

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Full Text Available Os autores relatam o caso de um paciente procedente do Município de Barreirinhas, MA, portador de leishmaniose cutânea disseminada, que apresentava 58 lesões distribuídas pelo corpo, sob os mais variados aspectos com predominância da lesão ulcerada. Discutem a dificuldade do diagnóstico laboratorial na fase inicial da investigação e suas implicações com a terapêutica. O parasita isolado e caracterizado pela técnica de anticorpos monoclonais foi a Leishmania viannia braziliensis. Esta forma da doença é diferente da leishmaniose cutânea difusa, encontrada no Maranhão, cujo agente etiológico é a Leishmania (Leishmania amazonensis, responsável pela grande maioria dos casos de leishmaniose tegumentar naquele Estado. Os possíveis mecanismos de disseminação das lesões são também discutidos neste trabalho.The authors describe a case of a patient from Barrreirinhas, MA with disseminated cutaneous leishmaniasis, who presented 58 lesions spread all over his body, with many different aspects, but ulcerative lesions were predominant. They discuss the difficulty of laboratorial diagnosis in the beginning of the investigation and its therapeutics implications. The parasite isolated yvas identified as Leishmania viannia braziliensis using monoclonal antibodies in the fluorescent antibody test. This form of the disease is different from the diffuse cutaneous leishmaniasis found in Maranhão, due to Leishmania (Leishmania amazonensis which is responsible for most of the cases of cutaneous leismaniasis in our State. The possible mechanisms of lesions dissemination are discussed.

Cloves Eduardo S. Galvão

1993-06-01

191

Polyclonal B cell activation in hamsters infected with parasites of the genus Leishmania.  

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Mesocricetus auratus (golden hamsters) infected with leishmania developed characteristic B cell immune responses that depended on the infecting species of leishmania. Thus, hamsters infected with viscerotropic leishmania (Leishmania donovani) developed antileishmania antibodies and hypergammaglobulinemia due to polyclonal activation of B cells as measured by reverse hemolytic plaque assay. In contrast, dermotropic leishmanias (L. braziliensis braziliensis and L. mexicana amazonensis) stimulat...

Campos-neto, A.; Bunn-moreno, M. M.

1982-01-01

192

Leishmania mexicana in Proechimys iheringi denigratus Moojen (Rodentia, Echimyidae) in a region endemic for American cutaneous leishmaniasis  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Três isolados de Leishmania foram obtidos de cinco entre 27 exemplares do roedor Proechimys iheringi denigratus, capturados na região de Três Braços, na mata atlântica do Estado da Bahia, Brasil. O isolamento desse parasito foi feito através de inoculação de triturado de pele, baço e fígado em patas [...] de hamsters. Em pelo menos um dos casos, (MTB-574), o parasito foi isolado da pele. Metas- tase foi observada nos hamsters inoculados, os parasitos cresceram abundantemente em meios artificiais de cultura e um padrão suprapapilario típico foi obtido em Lutzomyia longipalpis, indicando que o parasito pertence ao complexo L. mexicana. Todos os isolados reagiram positivamente com anticorpos monoclonais de L. m. mexicana e L. m. amazonensis. A análise isoenzimática diferenciou o parasito de isolados padrões de L. m. mexicana. L. m. amazonensis. L. m. aristedesi. L. m. pifanoi. L. m. garnhami e L. m. ssp(Goiás-W. Barbosa). O parasito parece ser uma subespécie de L. mexicana muito próxima à L. m. amazonensis, da qual difere pela menor mobilidade eletroforêtica de GPI, PEP e ALAT. Este e o primeiro registro do isolamento de um parasito do gênero Leishmania em um roedor capturado no Estado da Bahia. Abstract in english Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen a [...] nd skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa). These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.

Air C., Barretto; Norman E., Peterson; Ednaldo, Lago; Ana C., Rosa; Rosely S.M., Braga; Cesar A.C., Cuba; Julio A., Vexenat; Philip D., Marsden.

193

Leishmania mexicana in Proechimys iheringi denigratus Moojen (Rodentia, Echimyidae in a region endemic for American cutaneous leishmaniasis  

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Full Text Available Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen and skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa. These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.Três isolados de Leishmania foram obtidos de cinco entre 27 exemplares do roedor Proechimys iheringi denigratus, capturados na região de Três Braços, na mata atlântica do Estado da Bahia, Brasil. O isolamento desse parasito foi feito através de inoculação de triturado de pele, baço e fígado em patas de hamsters. Em pelo menos um dos casos, (MTB-574, o parasito foi isolado da pele. Metas- tase foi observada nos hamsters inoculados, os parasitos cresceram abundantemente em meios artificiais de cultura e um padrão suprapapilario típico foi obtido em Lutzomyia longipalpis, indicando que o parasito pertence ao complexo L. mexicana. Todos os isolados reagiram positivamente com anticorpos monoclonais de L. m. mexicana e L. m. amazonensis. A análise isoenzimática diferenciou o parasito de isolados padrões de L. m. mexicana. L. m. amazonensis. L. m. aristedesi. L. m. pifanoi. L. m. garnhami e L. m. ssp(Goiás-W. Barbosa. O parasito parece ser uma subespécie de L. mexicana muito próxima à L. m. amazonensis, da qual difere pela menor mobilidade eletroforêtica de GPI, PEP e ALAT. Este e o primeiro registro do isolamento de um parasito do gênero Leishmania em um roedor capturado no Estado da Bahia.

Air C. Barretto

1985-12-01

194

Leishmania mexicana in Proechimys iheringi denigratus Moojen (Rodentia, Echimyidae) in a region endemic for American cutaneous leishmaniasis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Três isolados de Leishmania foram obtidos de cinco entre 27 exemplares do roedor Proechimys iheringi denigratus, capturados na região de Três Braços, na mata atlântica do Estado da Bahia, Brasil. O isolamento desse parasito foi feito através de inoculação de triturado de pele, baço e fígado em patas [...] de hamsters. Em pelo menos um dos casos, (MTB-574), o parasito foi isolado da pele. Metas- tase foi observada nos hamsters inoculados, os parasitos cresceram abundantemente em meios artificiais de cultura e um padrão suprapapilario típico foi obtido em Lutzomyia longipalpis, indicando que o parasito pertence ao complexo L. mexicana. Todos os isolados reagiram positivamente com anticorpos monoclonais de L. m. mexicana e L. m. amazonensis. A análise isoenzimática diferenciou o parasito de isolados padrões de L. m. mexicana. L. m. amazonensis. L. m. aristedesi. L. m. pifanoi. L. m. garnhami e L. m. ssp(Goiás-W. Barbosa). O parasito parece ser uma subespécie de L. mexicana muito próxima à L. m. amazonensis, da qual difere pela menor mobilidade eletroforêtica de GPI, PEP e ALAT. Este e o primeiro registro do isolamento de um parasito do gênero Leishmania em um roedor capturado no Estado da Bahia. Abstract in english Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen a [...] nd skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa). These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.

Air C., Barretto; Norman E., Peterson; Ednaldo, Lago; Ana C., Rosa; Rosely S.M., Braga; Cesar A.C., Cuba; Julio A., Vexenat; Philip D., Marsden.

1985-12-01

195

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

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

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

2013-12-01

196

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

Scientific Electronic Library Online (English)

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

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

197

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

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

198

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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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.

Ralph Lainson

1987-09-01

199

Caracterização isoenzimática de isolados humanos de Leishmania sp (Kinetoplastida: Trypanosomatidae) dos municípios de Rio Preto da Eva e Manaus, Estado do Amazonas Isoenzymatic characterization of human isolates of Leishmania sp (Kinetoplastida: Trypanosomatidae) from the municipalities of Rio Preto da Eva and Manaus, State of Amazonas  

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Foram caracterizados/identificados por eletroforese de isoenzimas 23 isolados de Leishmania sp de pacientes dos municípios de Rio Preto da Eva e Manaus, analisando-se o grau de similaridade entre os organismos. Os resultados indicaram ocorrência de Leishmania guyanensis e Leishmania naiffi nestes dois ambientes e a heterogeneidade das amostras de Leishmania naiffi.Twenty-three isolates of Leishmania sp from patients in the municipalities of Rio Preto da Eva and Manaus were characterized...

Luanda de Paula Figueira; Michele Zanotti; Francimeire Gomes Pinheiro; Antonia Maria Ramos Franco

2008-01-01

200

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 atual [...] mente da célula de linhagem de macrófago humano U937. Aliando a microscopia à descrição das inter-relações morfológicas e à síntese de moléculas específicas foi possível esclarecer pontos sobre a biologia do parasito. O presente estudo mostra o acompanhamento do ciclo de crescimento da Leishmania chagasi em uma cinética realizada com células de linhagem McCoy, no período de 144 horas. Durante o processo, as transformações morfológicas foram reveladas pela reação de imunofluorescência indireta (RIFI) e as moléculas liberadas no meio extracelular foram observadas pelo método de SDS-PAGE, em intervalos de 24 horas no período de 144 horas. Observou-se que nas primeiras 72 horas, a forma promastigota da L. chagasi fica aderida à membrana das células com aspecto arredondado (amastigota-like). Em 96 horas as células infectadas apresentaram alterações morfológicas; em 120 horas, as células liberaram, para o meio extracelular, antígenos fluorescentes solúveis; e em 144 horas foram observadas novas formas alongadas dos parasitos como se fossem promastigotas. No SDS-PAGE, proteínas com pesos moleculares específicos são observadas em cada ponto da cinética, mostrando que a célula McCoy parece mimetizar o macrófago e que pode ser um modelo útil para o estudo da infecção do binômio leishmânia/célula. Abstract in english 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 cultur [...] e 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.

Yeda L., Nogueira; Paulo M., Nakamura; Eunice A. B., Galati.

2006-12-01

 
 
 
 
201

[Identification of Leishmania species isolated in human cases in Mato Grosso do Sul, by means of the polymerase chain reaction].  

Science.gov (United States)

Leishmaniases are endemic zoonoses in the State of Mato Grosso do Sul. Their etiological agents in this region of Brazil are Leishmania (Leishmania) chagasi, Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis. The polymerase chain reaction (PCR) is a tool with high specificity and sensitivity for identifying Leishmania species. This study examined 39 cryopreserved isolates of Leishmania that had been collected by bone marrow aspiration and/or lesion biopsy, depending on the clinical suspicion. The isolates were subjected to DNA extraction and PCR using the following primers: RV1/RV2 for identifying Leishmania (Leishmania) chagasi, a1/a2 for Leishmania (Leishmania) amazonensis and b1/b2 for Leishmania (Viannia) braziliensis.Leishmania (Leishmania) chagasi was the only species identified in the 37 cases of visceral leishmaniasis.Leishmania (Leishmania) amazonensis was identified in two isolates from patients with a diagnosis of cutaneous leishmaniasis. The results obtained confirm that it is possible to use these three pairs of primers as a tool for characterizing Leishmania isolates. PMID:19684979

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

2009-01-01

202

PCR-RFLP/Hsp70 para identificar y tipificar Leishmania de la región neotropical / PCR-RFLP/Hsp70 for identification and tipification of Leishmania from the tropical region  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se realizó la estandarización de las condiciones de amplificación del gen que codifica para la proteína de choque térmico de 70 kDa (Hsp70) de Leishmania mediante la reacción en cadena de la polimerasa (PCR-Hsp70), así como el análisis posterior de la longitud de los fragmentos de restricción (RFLP) [...] del producto amplificado, utilizando como molde ADN puro de una cepa de referencia de Leishmania mexicana. Se estudió la sensibilidad y especificidad analíticas de la PCR, así como la reproducibilidad, utilizando ADN de L. mexicana, L. amazonensis, L. guyanensis y L. lainsoni. Se obtuvo una banda de 1,3 Kpb, demostrándose la amplificación del gen que codifica para la Hsp70. Los patrones de bandas obtenidos tras la digestión enzimática, utilizando la enzima Hae III, permitieron establecer diferencias entre las especies estudiadas: L. guyanensis y L. lainsoni se diferencian entre sí y estas a su vez de L. mexicana y L. amazonensis, que mostraron un patrón de bandas común. La sensibilidad y especificidad analíticas de la técnica fueron adecuadas. Se demostró la factibilidad de identificar y tipificar especies del continente americano mediante la PCR-RFLP/Hsp70, y de utilizar la restricción enzimática del producto amplificado para distinguir entre Leishmania spp. y Trypanosoma cruzi, dándose un primer paso en el establecimiento de estos métodos moleculares en el laboratorio de referencia del instituto. Abstract in english The optimization of the PCR conditions for amplification of the gene coding for the 70kDa (HSp70) heat shock protein as well as the analysis of the restriction fragment length polymorphism (RFLP) were carried out. DNA from a reference strain of Leishmania mexicana was used as template. Analytical se [...] nsitivity and specificity, and reproducibility of PCR using DNA from L. mexicana, L.amazonensis, L. guyanensis and L. lainsoni were determined. A 1.3 kp band was obtained, which confirmed gene amplification. The band patterns derived from Haelll enzyme digestion allowed differentiating several species. L. guyanensis and L. lainsoni were different from each other, while L. mexicana and L. amazonensis, which shared a common pattern, were different from the other two species. Analytical sensitivity and specificity were adequate. The enzymatic restriction of the PCR product made it possible to differentiate Leishmania spp. from T. cruzi. The feasibility of identifying and typifying species from the American continent through PCR-RFLP/Hsp70 and of using enzymatic restriction of amplified product to distinguish Leishmania spp. from Trypanosoma cruzi was shown. This was the first step in implementing these molecular methods in the reference laboratory of the Institute.

Ana Margarita, Montalvo; Jorge, Fraga; Jaqueline, Aylema Romero; Lianet, Monzote; Ivon, Montano; Jean Claude, Dujardin.

203

PCR-RFLP/Hsp70 para identificar y tipificar Leishmania de la región neotropical PCR-RFLP/Hsp70 for identification and tipification of Leishmania from the tropical region  

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Full Text Available Se realizó la estandarización de las condiciones de amplificación del gen que codifica para la proteína de choque térmico de 70 kDa (Hsp70 de Leishmania mediante la reacción en cadena de la polimerasa (PCR-Hsp70, así como el análisis posterior de la longitud de los fragmentos de restricción (RFLP del producto amplificado, utilizando como molde ADN puro de una cepa de referencia de Leishmania mexicana. Se estudió la sensibilidad y especificidad analíticas de la PCR, así como la reproducibilidad, utilizando ADN de L. mexicana, L. amazonensis, L. guyanensis y L. lainsoni. Se obtuvo una banda de 1,3 Kpb, demostrándose la amplificación del gen que codifica para la Hsp70. Los patrones de bandas obtenidos tras la digestión enzimática, utilizando la enzima Hae III, permitieron establecer diferencias entre las especies estudiadas: L. guyanensis y L. lainsoni se diferencian entre sí y estas a su vez de L. mexicana y L. amazonensis, que mostraron un patrón de bandas común. La sensibilidad y especificidad analíticas de la técnica fueron adecuadas. Se demostró la factibilidad de identificar y tipificar especies del continente americano mediante la PCR-RFLP/Hsp70, y de utilizar la restricción enzimática del producto amplificado para distinguir entre Leishmania spp. y Trypanosoma cruzi, dándose un primer paso en el establecimiento de estos métodos moleculares en el laboratorio de referencia del instituto.The optimization of the PCR conditions for amplification of the gene coding for the 70kDa (HSp70 heat shock protein as well as the analysis of the restriction fragment length polymorphism (RFLP were carried out. DNA from a reference strain of Leishmania mexicana was used as template. Analytical sensitivity and specificity, and reproducibility of PCR using DNA from L. mexicana, L.amazonensis, L. guyanensis and L. lainsoni were determined. A 1.3 kp band was obtained, which confirmed gene amplification. The band patterns derived from Haelll enzyme digestion allowed differentiating several species. L. guyanensis and L. lainsoni were different from each other, while L. mexicana and L. amazonensis, which shared a common pattern, were different from the other two species. Analytical sensitivity and specificity were adequate. The enzymatic restriction of the PCR product made it possible to differentiate Leishmania spp. from T. cruzi. The feasibility of identifying and typifying species from the American continent through PCR-RFLP/Hsp70 and of using enzymatic restriction of amplified product to distinguish Leishmania spp. from Trypanosoma cruzi was shown. This was the first step in implementing these molecular methods in the reference laboratory of the Institute.

Ana Margarita Montalvo

2006-12-01

204

Caracterização isoenzimática de isolados humanos de Leishmania sp (Kinetoplastida: Trypanosomatidae dos municípios de Rio Preto da Eva e Manaus, Estado do Amazonas Isoenzymatic characterization of human isolates of Leishmania sp (Kinetoplastida: Trypanosomatidae from the municipalities of Rio Preto da Eva and Manaus, State of Amazonas  

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Full Text Available Foram caracterizados/identificados por eletroforese de isoenzimas 23 isolados de Leishmania sp de pacientes dos municípios de Rio Preto da Eva e Manaus, analisando-se o grau de similaridade entre os organismos. Os resultados indicaram ocorrência de Leishmania guyanensis e Leishmania naiffi nestes dois ambientes e a heterogeneidade das amostras de Leishmania naiffi.Twenty-three isolates of Leishmania sp from patients in the municipalities of Rio Preto da Eva and Manaus were characterized and identified by means of isoenzyme electrophoresis and the degree of similarity between the organisms was analyzed. The results indicated that Leishmania guyanensis and Leishmania naiffi were present in these two environments and that the Leishmania naiffi samples were heterogenous.

Luanda de Paula Figueira

2008-10-01

205

Contribuição para o estudo da prevalência da infecção por Leishmania infantum em gatos domésticos e errantes nos distritos de Lisboa e Viseu  

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A Leishmaniose visceral zoonótica causada por Leishmania infantum é considerada uma doença endémica no nosso País. Sabe-se que o cão é o principal hospedeiro reservatório, no entanto, o papel do gato (Felis catus) na epidemiologia da doença têm vindo adquirir um interesse crescente. A presente dissertação baseia-se em um rastreio epidemiológico da infecção por Leishmania infantum em gatos dos distritos de Lisboa e Viseu. A amostra total foi de 80 gatos correspondendo 40 animais...

Garrido, Joana Margarida Da Cruz Baptista Galva?o

2012-01-01

206

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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. Abstract in english 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 bloo [...] d-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.

Ralph, Lainson; Lee, Ryan; Jeffrey Jon, Shaw.

207

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

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Full Text Available Leishmaniasis occurs throughout the world and is one of the opportunistic infections that attack HIV-infected individuals. Few data are available on American cutaneous leishmaniasis (ACL in HIV-infected patients. Current research investigates the occurrence ofHIV-Leishmania co-infection in HIV-infected individuals in an endemic region in Southern of Brazil. A non-randomized transversal investigation, molecular and serum epidemiologic type, on the occurrence of ACL in 169 HIV-infected patients was undertaken. The patients were followed up at the Integrated Nucleus of Health of the city Maringá, Southern of Brazil. Results showed that 13 (7.7% of the HIV-infected patients also presented Leishmania (Viannia DNA, detectable in blood by PCR. Serology, direct research, culture and PCR in skin material produced negative results. PCR positiveness for Leishmania was not associated with CD4 T lymphocytes count, opportunistic disease, treatment, use of proteases inhibitors, tattooing/piercing or use of injectable drugs, residential environment or previous ACL history. Results show that HIVinfected patients who live in endemic areas may reveal Leishmania DNA in the blood without any ACL symptoms. Above findings may be attributed to anti-retrovirus medicine that controls viral replication and maintains the functionality of the immune system and to a possible anti- Leishmania activity of these drugs.As leishmanioses ocorrem em todo o mundo e são infecções oportunistas que afetam indivíduos portadores do vírus HIV. Este estudo investigou a ocorrência da co-infecção HIV-Leishmania em portadores do HIV numa região endêmica para LTA do Sul do Brasil. Foi realizado estudo transversal, não randomizado, utilizando metodologia molecular e sorológica, sobre a ocorrência de LTA em 169 portadores do HIV. Foram estudados pacientes atendidos no Núcleo Integrado de Saúde de Maringá, Paraná, Sul do Brasil. Observou-se que 13 (7,7% dos pacientes infectados pelo HIV também apresentavam o DNA de Leishmania (Viannia, detectável no sangue por PCR. A sorologia, pesquisa direta de Leishmania, cultura e PCR de lesões de pele foram negativas. A positividade da PCR não estava associada à contagem de linfócitos T CD4+, doença oportunista, tratamento, uso de inibidores de protease, tatuagem, uso de drogas injetáveis, ambiente da residência ou história prévia de LTA. Os resultados mostraram que indivíduos portadores do vírus HIV que residem em área endêmica podem apresentar o DNA de Leishmania sem manifestar sintomas de LTA. Estes resultados podem ser atribuídos a ação dos medicamentos anti retrovirais que controlam a replicação viral mantendo a integridade do sistema imunológico ou a uma possível atividade anti-Leishmania destas drogas.

Élide Aparecida Oliveira

2011-01-01

208

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

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

Elisalva T. Guimarães

2010-12-01

209

Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania  

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Full Text Available Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacin® and PH8 monovalent vaccine yielded the highest IFN-gamma levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L. amazonensis infection.

Mayrink Wilson

2002-01-01

210

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pri [...] ncipal 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. Abstract in english In the Americas, canine visceral leishmaniasis is caused by Leishmania (Leishmania) chagasi, an obligatory intracellular parasite of the phagocytic-monocytic system; the main histological changes associated with this disease occur in the lymphoid organs. Although dogs are considered to be the main c [...] arriers and disseminators of leishmaniasis in urban areas, there are few studies on the histopathologic and histomorphometric aspects in dogs naturally infected by L.chagasi analyzing the interaction between parasite and extracellular matrix. The current study characterize and quantify changes in the cellular and extracellular matrix (collagens type I and III) components of the popliteal lymph node from of 22 dogs with the natural infection by L. chagasi confirmed by indirect immuno-fluorescence assay (IFA) and compare theses findings with those fund in the popliteal lymph node from 10 non-infected dogs, that reacted negative in the IFA, and were clinically healthy. Lymph node fragments were longitudinally sliced and sections were processed for routine histopathology and stained by hematoxylin and eosin. For histomorphometry, additional sections from the same lymph node were fixed in glycol methacrylate and stained with toluidine blue. Lymph nodes from affected dogs were systemically enlarged, had increased numbers of lymphoid follicles, capsule hyperplasia and hypertrophy, and significant hyperplasia of lymphoid cells. In the lymph nodes from infected dogs, quantitative analyses of collagen fibers revealed predominance of type I collagen over type III fibers. These results demonstrate that dogs infected by L.chagasi experience degradation of the extracellular matrix components and consequently destruction of the lymphoid framework, thus altering nodal morphology.

Kris Régia J., Kondo; Cláudio César, Fonseca; Sérgio Luis P. da, Matta; Marlene Isabel V., Viloria.

211

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pri [...] ncipal 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. Abstract in english In the Americas, canine visceral leishmaniasis is caused by Leishmania (Leishmania) chagasi, an obligatory intracellular parasite of the phagocytic-monocytic system; the main histological changes associated with this disease occur in the lymphoid organs. Although dogs are considered to be the main c [...] arriers and disseminators of leishmaniasis in urban areas, there are few studies on the histopathologic and histomorphometric aspects in dogs naturally infected by L.chagasi analyzing the interaction between parasite and extracellular matrix. The current study characterize and quantify changes in the cellular and extracellular matrix (collagens type I and III) components of the popliteal lymph node from of 22 dogs with the natural infection by L. chagasi confirmed by indirect immuno-fluorescence assay (IFA) and compare theses findings with those fund in the popliteal lymph node from 10 non-infected dogs, that reacted negative in the IFA, and were clinically healthy. Lymph node fragments were longitudinally sliced and sections were processed for routine histopathology and stained by hematoxylin and eosin. For histomorphometry, additional sections from the same lymph node were fixed in glycol methacrylate and stained with toluidine blue. Lymph nodes from affected dogs were systemically enlarged, had increased numbers of lymphoid follicles, capsule hyperplasia and hypertrophy, and significant hyperplasia of lymphoid cells. In the lymph nodes from infected dogs, quantitative analyses of collagen fibers revealed predominance of type I collagen over type III fibers. These results demonstrate that dogs infected by L.chagasi experience degradation of the extracellular matrix components and consequently destruction of the lymphoid framework, thus altering nodal morphology.

Kris Régia J., Kondo; Cláudio César, Fonseca; Sérgio Luis P. da, Matta; Marlene Isabel V., Viloria.

2009-08-01

212

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

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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 the phagocytic-monocytic system; the main histological changes associated with this disease occur in the lymphoid organs. Although dogs are considered to be the main carriers and disseminators of leishmaniasis in urban areas, there are few studies on the histopathologic and histomorphometric aspects in dogs naturally infected by L.chagasi analyzing the interaction between parasite and extracellular matrix. The current study characterize and quantify changes in the cellular and extracellular matrix (collagens type I and III components of the popliteal lymph node from of 22 dogs with the natural infection by L. chagasi confirmed by indirect immuno-fluorescence assay (IFA and compare theses findings with those fund in the popliteal lymph node from 10 non-infected dogs, that reacted negative in the IFA, and were clinically healthy. Lymph node fragments were longitudinally sliced and sections were processed for routine histopathology and stained by hematoxylin and eosin. For histomorphometry, additional sections from the same lymph node were fixed in glycol methacrylate and stained with toluidine blue. Lymph nodes from affected dogs were systemically enlarged, had increased numbers of lymphoid follicles, capsule hyperplasia and hypertrophy, and significant hyperplasia of lymphoid cells. In the lymph nodes from infected dogs, quantitative analyses of collagen fibers revealed predominance of type I collagen over type III fibers. These results demonstrate that dogs infected by L.chagasi experience degradation of the extracellular matrix components and consequently destruction of the lymphoid framework, thus altering nodal morphology.

Kris Régia J. Kondo

2009-08-01

213

Diagnóstico molecular da taxa de infecção natural de flebotomíneos (Psychodidae, Lutzomyia por Leishmania sp na Amazônia maranhense Molecular diagnosis of the natural infection rate due to Leishmania sp in sandflies (Psychodidae, Lutzomyia in the Amazon region of Maranhão, Brazil  

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Full Text Available A taxa de infecção natural de três diferentes espécies de flebotomíneos por Leishmania foi estudada usando a técnica de reação em cadeia da polimerase. Primers específicos para Leishmania foram designados para examinar se os pools de flebotomíneos estavam infectadas. Um total de 1.100 fêmeas separadas em pools de 10 indivíduos foram examinados, consistindo de 50 Lutzomyia whitmani, 43 Lutzomyia triacantha e 17 Lutzomyia choti. De todos os pools analisados, 4 de Lutzomyia whitmani estavam positivos, mas nenhum pool das duas espécies restantes estava infectado. Deste modo, uma taxa de infecção de 0,4% foi verificada neste estudo. Esta taxa de infecção associada a estudos anteriores sugere que Lutzomyia whitmani transmite Leishmania aos mamíferos em Buriticupu, Maranhão.The natural infection rate due to Leishmania was studied in three different sandfly species using the polymerase chain reaction technique. Leishmania specific primers were designed to examine whether sandfly pools were infected. In total 1,100 female sandflies separated into pools of 10 individuals, consisting of 50 pools of Lutzomyia whitmani, 43 of Lutzomyia triacantha and 17 of Lutzomyia choti, were analyzed. Among all the pools examined, four pools of Lutzomyia whitmani were positive, but none of the pools of the other two species were infected. Thus, a total infection rate of 0.4% was established in this study. A similar infection rate was found in previous studies, suggesting that Lutzomyia whitmani transmits Leishmania to mammals in Buriticupu, Maranhão.

Yrla Nívea Oliveira-Pereira

2006-12-01

214

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

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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)

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

2000-07-01

215

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

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Full Text Available Os A.A. analisaram a resposta humoral nas lesões de 90 pacientes de Leishmaniose Tegumentar — causada por Leishmania braziliensis brasiliensis —, utilizando o método da imunoperoxidase para identificar nos tecidos a presença de IgA, IgG, IgM, fração C3 do complemento e fibrina. Constataram a 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.The Authors analysed the humoral response in biopsy material from 90 patients with Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis, utilising the immunoperoxidase method to identify IgA, IgG, IgM, C3 complement fraction and fibrin in the tissue. The presence of IgG, IgA and IgM was found in tissue plasma cells with a predominance of IgG and this was correlated significantly with the number of plasma cells in the lesion. The presence of immunoglobulins in the tissues stimulated the opsonisation of parasites and/or their antigens resulting in necrosis which represents one of the effective mechanisms to reduce parasite load. In ne- crotic areas and the walls of inflammed vessels immunoglobulins were deposited as well as the C3 fraction of complement and fibrin — immunocomplex fractions derived from the host. This tissue necrosis was interpreted as the result of the action of immunocomplexes in a region with equivalent or a smally excess of antigen (Arthus type reaction. The presence of parasite antigens expressed on the macrophage membrane in the initial phase of the lesion when in contact with tissue immunoglobulins, leads to the installation of an antigen-antibody reaction resulting in the appearance of necrosisin Mucocutaneous Leishmaniasis.

Albino Verçosa de Magalhães

1986-10-01

216

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

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os A.A. analisaram a resposta humoral nas lesões de 90 pacientes de Leishmaniose Tegumentar — causada por Leishmania braziliensis brasiliensis —, utilizando o método da imunoperoxidase para identificar nos tecidos a presença de IgA, IgG, IgM, fração C3 do complemento e fibrina. Constataram a presenç [...] a de IgA, IgC e IgM nos plasmócitos tissulares, com predomínio de IgG. Admitiram aue a passagem dessas imunoglobulinas para os tecidos possibilitando a opsonização do parasites e/ou de seus antígenos, permitiria a ocorrência de fenômenos necróticos que representam um dos mecanismos eficazes de redução da carga parasitária. Efetivamente, nas áreas de necrose e nas paredes dos vasos inflamados identificaram depósito de imunoglobulinas, fração C3 do complemento e fibrina — elementos do hospedeiro que fazem parte dos imunocomplexos. Interpretaram essa necrose tissular como o resultado da ação de imunocomplexos na região de equivalência ou com discreto excesso de antígenos ítipos ABTHTJS). A presença de antígenos parasitários, expressos nas membranas dos macrófagos quando em contato com imunoglobulinas tissulares, na fase inicial da lesão, possibilitaria a instalação de uma reação antígeno-anticorpo, a qual explicaria o aparecimento da necrose na Leishmaniose Tegumentar. Abstract in english The Authors analysed the humoral response in biopsy material from 90 patients with Mucocutaneous Leishmaniasis caused by Leishmania braziliensis braziliensis, utilising the immunoperoxidase method to identify IgA, IgG, IgM, C3 complement fraction and fibrin in the tissue. The presence of IgG, IgA an [...] d IgM was found in tissue plasma cells with a predominance of IgG and this was correlated significantly with the number of plasma cells in the lesion. The presence of immunoglobulins in the tissues stimulated the opsonisation of parasites and/or their antigens resulting in necrosis which represents one of the effective mechanisms to reduce parasite load. In ne- crotic areas and the walls of inflammed vessels immunoglobulins were deposited as well as the C3 fraction of complement and fibrin — immunocomplex fractions derived from the host. This tissue necrosis was interpreted as the result of the action of immunocomplexes in a region with equivalent or a smally excess of antigen (Arthus type reaction). The presence of parasite antigens expressed on the macrophage membrane in the initial phase of the lesion when in contact with tissue immunoglobulins, leads to the installation of an antigen-antibody reaction resulting in the appearance of necrosisin Mucocutaneous Leishmaniasis.

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

217

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

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

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

1999-11-01

218

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

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

219

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

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

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

2014-09-01

220

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

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

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

 
 
 
 
221

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

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

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

222

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

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

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

2007-09-01

223

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

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

Jackson Maurício Lopes Costa

1992-06-01

224

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

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

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

2011-12-01

225

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

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

Byanca Regina de Paiva

2007-01-01

226

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

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

Byanca Regina de, Paiva; Nagilá Francinete Costa, Secundino; Paulo Fillemon Paulocci, Pimenta; Eunice Aparecida Biacnhi, Galati; Heitor Franco, Andrade Junior; Rosely dos Santos, Malafronte.

227

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

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

Byanca Regina de, Paiva; Nagilá Francinete Costa, Secundino; Paulo Fillemon Paulocci, Pimenta; Eunice Aparecida Biacnhi, Galati; Heitor Franco, Andrade Junior; Rosely dos Santos, Malafronte.

228

A importância da infecção por Leishmania spp. e Dirofilaria immitis em gatos na região de Olhão  

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ABSTRACT - The importance of infection by Leishmania spp. and Dirofilaria immitis in cats in the region of Olhão - Leishmaniosis and Heartworm are vector-borne parasitic diseases the first one caused by a protozoa, Leishmania infantum, and the second by a nematode, Dirofilaria immitis. Although dog is considered the main host and reservoir host, these parasitoses have been reported in other animals, namely in the domestic cat. Despite the fact that these emerging diseases ...

Ramos, Cla?udia Patri?cia Gonc?alves Dos

2012-01-01

229

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster Avaliação histológica da lesão induzida pela inoculação de Leishmania mexicana na bolsa jugal do hamster  

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Full Text Available We have studied the role of the immune response in the morphology of the leishmaniotic granuloma induced in the cheek pouch of hamsters, an immunologically privileged site, after inoculation of 3 x 10(5 Leishmania mexicana. Animals were histologically and immunologically evaluated until 120 days after inoculation. Independent of the time of sacrifice, the animals were always non-reactors to the footpad test (FPT. At histology, the introduction of L. mexicana in the cheek pouch leads to an abscess that evolves to a granulomatous reaction rich in amastigote forms, and later it leads to resolution, even in the absence of immune response detectable by FPT. Our results demonstrate that the development of immune response is not preponderant for the control of infection induced by L. mexicana inoculated subcutaneously in the cheek pouch of the hamster. It also suggests that the macrophages present in the leishmaniotic granuloma are capable of eliminating this parasite, even in the absence of immune response evaluated by FPT.No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5 Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mexicana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar.

Maria Sueli Parreira de Arruda

2002-08-01

230

A2 and other visceralizing proteins of Leishmania: role in pathogenesis and application for vaccine development.  

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Visceral leishmaniasis is a re-emergent disease and a significant cause of morbidity worldwide. Amongst the more than 20 Leishmania species, Leishmania donovani, Leishmania infantum and more rarely Leishmania amazonensis are associated with visceral leishmaniasis. A major question in leishmaniasis research is how these species migrate to and infect visceral organs whereas other species such as Leishmania major and Leishmania braziliensis remain in the skin, causing tegumentary leishmaniasis. Here we present the more recent advances and approaches towards the identification of species-specific visceralizing factors of Leishmania, such as the A2 protein, leading to a better understanding of parasite biology. We also discuss their potential use for the development of a vaccine for visceral leishmaniasis. PMID:24264241

Fernandes, Ana Paula; Canavaci, Adriana Monte Cassiano; McCall, Laura-Isobel; Matlashewski, Greg

2014-01-01

231

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

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

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

1993-09-01

232

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

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

MICHALSKY Érika M.

2002-01-01

233

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

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

Elisalva T., Guimarães; Milena S., Lima; Luana A., Santos; Ivone M., Ribeiro; Therezinha B. C., Tomassini; Ricardo Ribeiro dos, Santos; Washington L. C. dos, Santos; Milena B. P., Soares.

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Leishmaniose tegumentar americana causada por Leishmania (Viannia braziliensis, em área de treinamento militar na Zona da Mata de Pernambuco American tegumentary leishmaniasis caused by Leishmania (Viannia braziliensis in military training area of Zona da Mata in Pernambuco  

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Full Text Available Este estudo tem como objetivo geral caracterizar a epidemiologia da leishmaniose tegumentar americana em unidade de treinamento militar, localizada no Estado de Pernambuco. Entre 2002 e 2003, vinte e três casos foram diagnosticados através de exame clínico, detecção do parasita e teste de intradermoarreação de Montenegro. Sete amostras de Leishmania (Viannia braziliensis foram isoladas destes pacientes, identificadas através de reações com anticorpos monoclonais específicos e perfil eletroforético com isoenzimas. Um inquérito epidemiológico de prevalência da infecção por IDRM foi realizado na população que realizou treinamento neste período, no qual foi identificada uma prevalência de 25,3% de infecção. Os dados obtidos, associados com achados prévios nesta área, apresentam evidências da manutenção de um ciclo enzoótico, com a ocorrência de surtos periódicos de leishmaniose tegumentar americana posteriormente à realização de treinamentos nas áreas de floresta Atlântica remanescente.The aim of work was to study the epidemiology of American tegumentary leishmaniasis in a military training unit situated in Zona da Mata region of Pernambuco State. Between 2002 and 2003 twenty-three cases were notified by clinical exam, detection and/or isolation of parasite and Montenegro skin test. Seven stocks of Leishmania (Viannia braziliensis were obtained from patients, identified by a panel of specific monoclonal antibodies and isoenzymatic electrophoresis profiles. An epidemiologic survey on prevalence of infection was carried out by Montenegro skin test in the population that underwent training activities during the same period, out of which 25.3% were identified as positive. These results in association with previous data from this area, shows the maintenance of a primary transmission cycle and the occurrence of periodical outbreaks after training activities in local areas of remnant Atlantic rain forest.

Maria S. Andrade

2005-05-01

235

Leishmaniose tegumentar americana causada por Leishmania (Viannia) braziliensis, em área de treinamento militar na Zona da Mata de Pernambuco / American tegumentary leishmaniasis caused by Leishmania (Viannia) braziliensis in military training area of Zona da Mata in Pernambuco  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este estudo tem como objetivo geral caracterizar a epidemiologia da leishmaniose tegumentar americana em unidade de treinamento militar, localizada no Estado de Pernambuco. Entre 2002 e 2003, vinte e três casos foram diagnosticados através de exame clínico, detecção do parasita e teste de intradermo [...] arreação de Montenegro. Sete amostras de Leishmania (Viannia) braziliensis foram isoladas destes pacientes, identificadas através de reações com anticorpos monoclonais específicos e perfil eletroforético com isoenzimas. Um inquérito epidemiológico de prevalência da infecção por IDRM foi realizado na população que realizou treinamento neste período, no qual foi identificada uma prevalência de 25,3% de infecção. Os dados obtidos, associados com achados prévios nesta área, apresentam evidências da manutenção de um ciclo enzoótico, com a ocorrência de surtos periódicos de leishmaniose tegumentar americana posteriormente à realização de treinamentos nas áreas de floresta Atlântica remanescente. Abstract in english The aim of work was to study the epidemiology of American tegumentary leishmaniasis in a military training unit situated in Zona da Mata region of Pernambuco State. Between 2002 and 2003 twenty-three cases were notified by clinical exam, detection and/or isolation of parasite and Montenegro skin tes [...] t. Seven stocks of Leishmania (Viannia) braziliensis were obtained from patients, identified by a panel of specific monoclonal antibodies and isoenzymatic electrophoresis profiles. An epidemiologic survey on prevalence of infection was carried out by Montenegro skin test in the population that underwent training activities during the same period, out of which 25.3% were identified as positive. These results in association with previous data from this area, shows the maintenance of a primary transmission cycle and the occurrence of periodical outbreaks after training activities in local areas of remnant Atlantic rain forest.

Maria S., Andrade; Maria E. F., Brito; Salomão Thomaz da, Silva; Bruna S., Lima; Éricka L., Almeida; Elisângela L., Albuquerque; José F., Marinho Júnior; Edna, Ishikawa; Elisa, Cupolillo; Sinval P., Brandão-Filho.

236

An agent-based model for Leishmania major infection  

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

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

237

Distinctions between promastigotes of Leishmania species developing in the digestive tract of laboratory reared Lutzomyia longipalpis  

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Full Text Available Female Lutzomya longipalpis were exposed to infection by three different species/strains of Leishmania. When the insects were dissected four days after exposure, stained preparations were made of the flagellates contained in the digestive tract. Using traditional morphometric methods, L. amazonensis, L. guyanensis and an unnamed species of the mexicana complex could be distinguished from one another.

Ana Lúcia F. F. da Silva

1991-03-01

238

DNA amplification in arsenite-resistant Leishmania.  

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Arsenite-resistant variants of a trypanosomatid protozoan, Leishmania mexicana amazonensis, were selected in vitro by stepwise increases of sodium arsenite concentrations up to 30 microM in the culture medium. These variants were found to contain amplified DNA as extrachromosomal supercoiled molecules of about 69 kb. They originate from a single chromosome in the wild-type cells. There is evidence of chromosomal changes in these cells associated with the selection for arsenite resistance. The apparent absence of these circular molecules in the wild type and their loss from the drug-sensitive revertants suggest amplification of chromosomal DNA into these extrachromosomal circles as the mechanism of arsenite resistance. PMID:2909386

Detke, S; Katakura, K; Chang, K P

1989-01-01

239

Estudo da competência vetorial de Lutzomyia intermedia (Lutz & Neiva, 1912 para Leishmania (Viannia braziliensis, Vianna, 1911  

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Full Text Available Estudou-se a competência vetorial de Lutzomyia intermedia (Diptera: Psychodidae do Vale do Ribeira (SP para estirpes de Leishmania (Viannia braziliensis (Kinetoplastida: Trypanosomatidae, mediante pesquisa de infectividade natural; exposições de fêmeas silvestres e colonizadas (F1 às lesões de hamsters experimentalmente infectados e testes de transmissão via picada. A infectividade natural e os testes de transmissão revelaram-se negativos e, nas exposições, foram obtidas positividades de 74% (123+/166 dissecados e 70% (115+/164 dissecados para fêmeas silvestres e colonizadas respectivamente, e o desenvolvimento das formas evolutivas compatíveis com o modelo Peripilaria. A suscetibilidade às estirpes testadas associada aos indicadores epidemiológicos concorrem para a suspeita do papel vetorial de Lutzomyia intermedia na região estudada.

Silva Antonio Carlos da

2001-01-01

240

The in vitro leishmanicidal activity of hexadecylphosphocholine (miltefosine) against four medically relevant Leishmania species of Brazil  

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Full Text Available SciELO Brazil | Language: English Abstract in english The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH) was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) chagasi. The activity of [...] miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania) donovani, which is known to be sensitive to the effects of miltefosine. The IC50 and IC90 results suggested the New World species harboured similar in vitro susceptibilities to miltefosine; however, miltefosine was approximately 20 times more active against the Old World L. (L.) donovani than against the New World L. (L.) chagasi species. The selectivity index varied from 17.2-28.9 for the New World Leishmania species and up to 420.0 for L. (L.) donovani. The differences in susceptibility to miltefosine suggest that future clinical trials with this drug should include a laboratory pre-evaluation and a dose-defining step.

Eliane de, Morais-Teixeira; Quesia Souza, Damasceno; Mariana Kolos, Galuppo; Alvaro José, Romanha; Ana, Rabello.

 
 
 
 
241

The in vitro leishmanicidal activity of hexadecylphosphocholine (miltefosine against four medically relevant Leishmania species of Brazil  

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Full Text Available The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania amazonensis, Leishmania (Viannia braziliensis, Leishmania (Viannia guyanensis and Leishmania (Leishmania chagasi. The activity of miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania donovani, which is known to be sensitive to the effects of miltefosine. The IC50 and IC90 results suggested the New World species harboured similar in vitro susceptibilities to miltefosine; however, miltefosine was approximately 20 times more active against the Old World L. (L. donovani than against the New World L. (L. chagasi species. The selectivity index varied from 17.2-28.9 for the New World Leishmania species and up to 420.0 for L. (L. donovani. The differences in susceptibility to miltefosine suggest that future clinical trials with this drug should include a laboratory pre-evaluation and a dose-defining step.

Eliane de Morais-Teixeira

2011-06-01

242

Occurrence of anti-Leishmania spp., Neospora caninum, and Toxoplasma gondii antibodies in dog sera from Veterinary Hospital from Universidade Estadual de LondrinaOcorrência de anticorpos contra Leishmania spp., Neospora caninum E Toxoplasma gondii em soros de cães atendidos no Hospital Veterinário da Universidade Estadual de Londrina-Pr  

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Full Text Available The aim of this study was to detect the presence of IgG antibodies anti-Leishmania spp., Toxoplasma gondii and Neospora caninum in dogs from a Veterinary Hospital from Universidade Estadual de Londrina. Blood samples from 112 animals were obtained by jugular venipuncture to obtain sera. The samples were tested by indirect immunofluorescence to detect antibodies anti-Leishmania spp., anti-N. caninum and anti-T. gondii. Thirteen (11.61%, 25 (22.32%, and 57 (50.89% samples were positive for Leishmania spp., N. caninum, and T. gondii, respectively. The co-presence of anti-Leishmania spp. and N. caninum was observed in 6 (5.36%, anti-Leishmania spp. and anti-T. gondii in 8 (14.7%, and anti-N. caninum and anti-T. gondii in 18 (16.07% samples. The co-presence of anti-Leishmania spp., anti-N. caninum and anti-T. gondii was observed in 5 (4.46% dogs. There was a higher prevalence of Leishmania in Toxoplasma and Neospora positive animals, however, these results were not statistically significant (range p = 0.052 p = 0.06. The dogs have an important role in the epidemiological cycle of these diseases, which are important in animal and public health. The northern state of Paraná is an endemic area for human cutaneous leishmaniasis, therefore, studies should be conducted to uncover the real role of dogs as reservoirs of Leishmania to humans in the state. O objetivo do presente trabalho foi detectar a presença de anticorpos contra Leishmania spp., Neospora caninum e Toxoplasma gondii em cães atendidos no Hospital Veterinário, da Universidade Estadual de Londrina. Amostras de 112 animais foram obtidas por venopunção jugular ou cefálica com posterior obtenção dos soros. Estas foram submetidas à técnica de imunofluorescência indireta para detecção de anticorpos da classe IgG anti-Leishmania spp, anti-N. caninum e anti-T. gondii. Dos 112 soros examinados, 13 (11,61%, 25 (22,32% e 57 (50,89% foram positivos para Leishmania spp., N. caninum e T. gondii, respectivamente. A co-presença de anticorpos anti-Leishmania spp. e N. caninum foi observada em 6 (5,36% amostras, anticorpos anti-Leishmania spp. e anti-T. gondii em 8 (7,14%, e anticorpos anti-N. caninum e anti-T. gondii em 18 (16,07% amostras. A co-presença de anticorpos anti- Leishmania spp., anti-N. caninum e anti-T. gondii foi observada em 5 (4,46% cães. Verificou-se uma maior prevalência de Leishmania nos animais positivos para Toxoplasma e Neospora, embora estes resultados não tenham sido estatisticamente significativos (p?0.06. Os cães são importantes no ciclo epidemiológico das enfermidades em estudo, sendo estas doenças importantes do ponto de vista de saúde animal, ou de saúde pública. A região norte do estado do Paraná é uma área endêmica para leishmaniose tegumentar humana, portanto, estudos devem ser realizados para desvendar o real papel dos cães como reservatórios da Leishmania para seres humanos no estado.

Dauton Luiz Zulpo

2012-10-01

243

Analysis of the specificity of human antibodies to antigens of Leishmania braziliensis braziliensis Análise da especificidade de anticorpos humanos a antígenos de Leishmania braziliensis braziliensis  

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Full Text Available The antigenicity of promastigotes of Leishmania braziliensis braziliensis (L. b.braziliensis treated with 1% sodium desoxycholate in 10 mM Tris-Hcl pH 8.2 was analysed by immunoblot using as probes sera from American cutaneous leishmaniasis (ACL, American visceral leishmaniasis (AVL, schistosomiasis, malaria and Chagas' disease. The ACL sera reacted constantly with a 60 kD band. No reactivity to this protein was observed with sera from the other diseases above mentioned indicating that the 60 kD protein may be used in serodiagnosis for ACL.A antigenicidade de promastigotas de Leishmania braziliensis braziliensis tratadas com desoxicolato de sódio 1% tampão TrisHCl 10 mM pH 8.2 foi determinada por immunoblot usando soros de pacientes com leishmaniose cutânea e mucocutânea, leishmaniose visceral, esquistossomose, malária e doença de Chagas. Os soros de pacientes com leishmaniose cutânea e mucocutânea apresentaram reação positiva com uma banda de 60 kD. Não se observou reatividade para esta fração em soros de pacientes com outras doenças parasitárias acima mencionadas, indicando que esta pode ser utilizada no sorodiagnóstico de leishmaniose tegumental.

Aoi Masuda

1989-08-01

244

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

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

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

2013-09-01

245

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

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

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

246

Surface antigenic change during differentiation of a parasitic protozoan, Leishmania mexicana: Identification by monoclonal antibodies.  

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The fusion of SP2/0 myeloma cells with spleen cells from mice immunized with Leishmania mexicana amazonensis promastigotes produced hybridoma clones. Indirect immunofluorescent antibody assay with live leishmanias showed that the monoclonal antibody 6H12 recognized only the antigens bound to the surface of L. mexicana amazonensis promastigotes. It also showed that the antibody bound to neither amastigotes of this species nor to other Leishmania species--i.e., L. braziliensis braziliensis, L. tropica, and L. donovani. Monoclonal antibodies from three other clones (4D11, 4H9, and 6A11) were found to compete with 6H12 for binding to L. mexicana promastigotes. With lysates of [35S]methionine-labeled promastigotes, all four monoclonal antibodies precipitated the same triplet set of protein bands at the approximately equal to 68,000-dalton region, whereas another monoclonal antibody (6G5) precipitated a different band at approximately equal to 90,000 daltons. During differentiation of L. mexicana amazonensis from amastigotes to promastigotes, there was a 4- to 8-fold increase above the initial level in the binding of 6H12 monoclonal antibody to leishmanias, as detected by enzyme-linked immunosorbent assay and quantitative fluorometric assay, respectively. Thus, we have demonstrated the use of monoclonal antibodies as probes for antigens that change during leishmanial differentiation. PMID:6961414

Fong, D; Chang, K P

1982-12-01

247

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

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os Autores apresentam dados sôbre tentativas de transmissão experimental da Leishmania donovani pela picada de Lutzomyia longipalpis entre cães. Dois cães jovens sadios foram picados respectivamente por dois e sete flebótomos ricamente infectados e não adquiriram leishmaniose. [...] Abstract in english In 1958, attempts were made to transmit Leishmania donovani (Leveran & Mensnil) from dog to dog by the bite of Lutzomya longipalpis (Lutz & Neiva) in the State of Ceará, Brazil. Two young, healthy dogs (2-3 months old) were bitten by 31 laboratory reared sanflies fed previously on infected dogs; nin [...] e of the sandflies were later found to be infected with L. donovani, but none of the healthy dogs on which they fed became infected.

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

248

Histopatologia da leishmaniose tegumentar por Leishmania braziliensis braziliensis: 1. Padrões histopatológicos e estudo evolutivo das lesões Histopathology of mucocutaneous leishmaniasis caused by Leishmania braziliensis braziliensis: 1. Histological patterns and evolutive study of the lesions  

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Full Text Available Os autores analisam material de biópsias de 378 casos de Leishmaniose Tegumentar, causada por Leishmania braziliensis braziliensis, da localidade endêmica de Três Braços (Estado da Bahia. O parásitos, embora escassos, foram encontrados em 63,7% dos casos da forma cutânea e em 37,5% dos casos da forma mucosa. As alterações dérmicas ou do córion da mucosa permitiram identificar cinco padrões histopatológicos: 1 Reação Exsudativa Celular, constituída por um infiltrado histiolinfoplasmocitário; 2 Reação Exsudativa e Necrótica, na qual ocorre uma necrose no seio do infiltrado inflamatório; 3 Reação Exsudativa e Necrótico-Granulomatosa, que corresponde ao quadro descrito como inflamação crônica granulomatosa com necrose; 4 Reação Exsudativa e Granulomatosa, onde se observa uma reação granulomatosa desorganizada, sem que esteja presente necrose tecidual; 5 Reação Exsudativa e Tuberculóide, caracterizada pelo granuloma tuberculóide. O estudo evolutivo realizado em 49 casos, mostrou que houve uma mudança de padrão histopatológico observada, em biópsias sucessivas, em 63,2% dos casos da forma cutânea e em 45,4% dos casos da forma mucosa. Através desse estudo, é possível afirmar-se que o padrão de Reação Exsudativa Celular constitui o quadro inicial e final da lesão, com os demais padrões aparecendo interposto durante a evolução da doença.The Authors describe the histopathological findings observed in biopsies from 378 cases of Mucocutaneous Leishmaniasis, caused by Leishmania braziliensis braziliensis. All the patients lived in the locality of Três Braços, State of Bahia, an endemic area of Leishmaniasis in Brazil. Parasites were found in 63.7% of patients with cutaneous form and in 35.7% of cases with mucous lesions, although always in reduced number. Histopathologic findings allowed the caracterization of five different patterns: 1. Exsudative-cellular reaction, due to infiltraction of histiocytes, lymphocytes and plasm cells; 2. Exsudative-necrotic reaction, characterized by the association of necrosis with cellular infiltration; 3. Exsudative and necrotic-granulomatous reaction, corresponding to pattern described as chronic-granulomatous inflammation with necrosis; 4. Exsudativegranulomatous reaction, characterized a disorganized granulomatous reaction, without tissue necrosis; 5. Exsudative-tuberculoid reaction — in which a typical tuberculoid granuloma is formed. The follow-up study in 49 patients showed, in sucessive biopsies, changes in the histopathologic patterns in 63.2% of cutaneous forms and in 45.4% of the mucous forms. It was concluded that the exsudative-cellular reaction represents both the inicial and final pattern of Mucocutaneous Leishmaniasis lesion. The other four histopathologic patterns characterize intermediate forms found during the evolution of the disease.

Albino Verbosa de Magalhães

1986-08-01

249

Fractionation of Lizard Leishmania promastigote Protein  

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Full Text Available The objective of this study was fractionation of Lizard Leishmania promastigote. Mass culture of lizard Leishmania promastigote was provided. Fractionation was carried out by ammonium sulfate precipitation and size exclusion chromatography. The 19.2, 21.5, 25, 30, 35, 64 and 78 kDa fractions were found and they used for vaccination against mouse leishmaniasis.

B. Kazemi

2004-01-01

250

Potential utility of hyperbaric oxygen therapy and propolis in enhancing the leishmanicidal activity of glucantime / A utilidade da terapia de oxigenação hiperbárica e própolis em potencializar a atividade leishmanicida do glucantime  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Nesse trabalho foi avaliada a eficácia da terapia da oxigenação hiperbárica (HBO), aplicada em combinação ou não com o tratamento com glucantime, durante a infecção com Leishmania amazonensis. O efeito de gel da própolis vermelha de origem brasileira (propaina) aplicado em combinação ou não com o tr [...] atamento com glucantime, também foi avaliado durante infecção com esse parasita. A inibição da infecção de macrófagos tratados com glucantime em combinação com HBO foi maior que a de macrófagos tratados apenas com glucantime ou HBO. A linhagem murina susceptível, BALB/c, infectada no dorso com L. amazonensis, tratada com glucantime e exposta a HBO, mostrou durante o curso da doença, fases em que as lesões eram menores do que a de camundongos apenas tratados com glucantime; observou-se revascularização da pele da lesão e baixa produção de interferon-gama em células de linfonodos desses animais. O tratamento com propaina não foi eficiente na cura das lesões, apesar de lesões menos exsudativas serem observadas em animais tratados com propaina ou propaina combinada ao tratamento com glucantime. Os resultados demonstram que tanto HBO como a própolis vermelha em combinação com glucantime, são promissoras no tratamento da leishmaniose cutânea. Novos estudos devem ser realizados para avaliar tratamentos e outros protocolos em diferentes modelos murinos da leishmaniose Abstract in english In this study we investigated the efficacy of hyperbaric oxygen (HBO) therapy, alone or combined with the pentavalent antimonial glucantime on Leishmania amazonensis infection. In parallel, the effect of Brazilian red propolis gel (propain) alone or combined with glucantime on L. amazonensis infecti [...] on was evaluated. The inhibition of the infection in macrophages treated with glucantime in combination with HBO exposition was greater than that of macrophages treated with glucantime alone or HBO alone. The susceptible mouse strain BALB/c infected in the shaved rump with L. amazonensis treated with glucantime and exposed to HBO showed: time points in the course of the disease in which lesions were smaller than those of mice treated with glucantime alone and revascularization of the skin in the lesion site; interferon-gamma (IFN-g) levels were not elevated in lymph node cells from these animals. Propain alone was not efficient against lesions, although less exudative lesions were observed in animals treated with propain alone or combined with glucantime. These results reveal the potential value of HBO and red propolis in combination with glucantime for treating cutaneous leishmaniasis and encourage further studies on the effect of more aggressive HBO, propolis and glucantime therapies on different mouse models of leishmaniasis.

Diana Copi, Ayres; Thiago Antonio, Fedele; Maria Cristina, Marcucci; Selma, Giorgio.

2011-12-01

251

Potential utility of hyperbaric oxygen therapy and propolis in enhancing the leishmanicidal activity of glucantime / A utilidade da terapia de oxigenação hiperbárica e própolis em potencializar a atividade leishmanicida do glucantime  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Nesse trabalho foi avaliada a eficácia da terapia da oxigenação hiperbárica (HBO), aplicada em combinação ou não com o tratamento com glucantime, durante a infecção com Leishmania amazonensis. O efeito de gel da própolis vermelha de origem brasileira (propaina) aplicado em combinação ou não com o tr [...] atamento com glucantime, também foi avaliado durante infecção com esse parasita. A inibição da infecção de macrófagos tratados com glucantime em combinação com HBO foi maior que a de macrófagos tratados apenas com glucantime ou HBO. A linhagem murina susceptível, BALB/c, infectada no dorso com L. amazonensis, tratada com glucantime e exposta a HBO, mostrou durante o curso da doença, fases em que as lesões eram menores do que a de camundongos apenas tratados com glucantime; observou-se revascularização da pele da lesão e baixa produção de interferon-gama em células de linfonodos desses animais. O tratamento com propaina não foi eficiente na cura das lesões, apesar de lesões menos exsudativas serem observadas em animais tratados com propaina ou propaina combinada ao tratamento com glucantime. Os resultados demonstram que tanto HBO como a própolis vermelha em combinação com glucantime, são promissoras no tratamento da leishmaniose cutânea. Novos estudos devem ser realizados para avaliar tratamentos e outros protocolos em diferentes modelos murinos da leishmaniose Abstract in english In this study we investigated the efficacy of hyperbaric oxygen (HBO) therapy, alone or combined with the pentavalent antimonial glucantime on Leishmania amazonensis infection. In parallel, the effect of Brazilian red propolis gel (propain) alone or combined with glucantime on L. amazonensis infecti [...] on was evaluated. The inhibition of the infection in macrophages treated with glucantime in combination with HBO exposition was greater than that of macrophages treated with glucantime alone or HBO alone. The susceptible mouse strain BALB/c infected in the shaved rump with L. amazonensis treated with glucantime and exposed to HBO showed: time points in the course of the disease in which lesions were smaller than those of mice treated with glucantime alone and revascularization of the skin in the lesion site; interferon-gamma (IFN-g) levels were not elevated in lymph node cells from these animals. Propain alone was not efficient against lesions, although less exudative lesions were observed in animals treated with propain alone or combined with glucantime. These results reveal the potential value of HBO and red propolis in combination with glucantime for treating cutaneous leishmaniasis and encourage further studies on the effect of more aggressive HBO, propolis and glucantime therapies on different mouse models of leishmaniasis.

Diana Copi, Ayres; Thiago Antonio, Fedele; Maria Cristina, Marcucci; Selma, Giorgio.

252

Patogenia da leishmaniose cutânea experimental: a importância da necrose na eliminação dos parasitos das lesões  

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Full Text Available Um estudo histopatológico e ultraestrutural das lesões da leishmaniose cutânea causada pela Leishmania mexicana amazonensis em duas cepas isogênicas de camundongo, uma susceptível (Balb/c e outra resistente (A/J, demonstrou que os amastigotas ficavam bem preservados nos vacúolos parasitóforos dos macrófagos, igualmente em ambas as cepas. A reação de imunofluorescência revelou antigenos parasitários no interior e na membrana dos macrófagos de maneira idêntica para ambas as cepas. A diferença ocorria quando os macrófagos apareciam destruídos e as leishmanias ficavam livres ou fagocitadas por polimorfonucleares, neutrófilos e eosinófilos. Estes parasitos exibiam então graus variáveis de nítidas alterações degenerativas. No camundongo resistence, a necrose, de tipo caseoso ou fibrinóide, era mais disseminada e mais freqüente que no animal susceptível. Os achados observados indicaram que as leishmanias não são destruídas no interior dos macrófagos e sim fora deles, especialmente quando fagocitadas por leucócitos polimorfonucleares. A necrose apareceu como o mecanismo mais saliente através do qual o hospedeiro elimina os parasitos das lesões, sendo a mesma um aspecto importante da reação de hipersensibilidade tardia que ocorre nos animais resistentes.Amastigotes of Leshmania mexicana amazonensis appeared healthy and well preserved within the parasitophorous vacuoles of macrophages during the infection of a susceptible (Balb/c or a relatively resistant (A/J inbred strain of mice. Immunofluorescence showed the presence of leishmanial antigens within infected macrophages and in their external membranes similar for both strains. When the amastigotes were found extracellularly or within polymorphonuclear neutrophils or eosinophils, marked ultrastructural degenerative changes were observed in them. Such necrotic alterations were seen frequently in the resistant mice and rarely in the susceptible ones. Thus, necrosis of parasitized macrophages appeared as a major mechanism through which the resistant host eliminates the parasites from the lesions. It may be considered as a histological marker of resistance in leishmaniasis and represents a prominent component of the delayed-type immunological mechanism occurring in resistant hosts.

Zilton A. Andrade

1984-12-01

253

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

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

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

2013-12-01

254

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

Scientific Electronic Library Online (English)

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

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

255

Distinctions between promastigotes of Leishmania species developing in the digestive tract of laboratory reared Lutzomyia longipalpis  

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Full Text Available SciELO Brazil | Language: English Abstract in english Female Lutzomya longipalpis were exposed to infection by three different species/strains of Leishmania. When the insects were dissected four days after exposure, stained preparations were made of the flagellates contained in the digestive tract. Using traditional morphometric methods, L. amazonensis [...] , L. guyanensis and an unnamed species of the mexicana complex could be distinguished from one another.

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

256

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

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

GM Santos

2012-01-01

257

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

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

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

258

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

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

Haroldo Sérgio da S. Bezerra

1996-04-01

259

The scavenger receptor MARCO is involved in Leishmania major infection by CBA/J macrophages.  

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CBA/J mice are resistant to Leishmania major infection but are permissive to L. amazonensis infection. In addition, CBA/J macrophages control L. major but not L. amazonensis infection in vitro. Phagocytosis by macrophages is known to determine the outcome of Leishmania infection. Pattern recognition receptors (PRR) adorning antigen presenting cell surfaces are known to coordinate the link between innate and adaptive immunity. The macrophage receptor with collagenous structure (MARCO) is a PRR that is preferably expressed by macrophages and is capable of binding Gram-positive and Gram-negative bacteria. No research on the role of MARCO in Leishmania-macrophage interactions has been reported. Here, we demonstrate, for the first time, that MARCO expression by CBA/J macrophages is increased in response to both in vitro and in vivo L. major infections, but not to L. amazonensis infection. In addition, a specific anti-MARCO monoclonal antibody reduced L. major infection of macrophages by 30%-40% in vitro. The draining lymph nodes of anti-MARCO-treated mice displayed a reduced presence of immunolabelled parasite and parasite antigens, as well as a reduced inflammatory response. These results support the hypothesis that MARCO has a role in macrophage infection by L. major in vitro as well as in vivo. PMID:19292770

Gomes, I N; Palma, L C; Campos, G O; Lima, J G B; DE Almeida, T F; DE Menezes, J P B; Ferreira, C A G; Santos, R R Dos; Buck, G A; Manque, P A M; Ozaki, L S; Probst, C M; DE Freitas, L A R; Krieger, M A; Veras, P S T

2009-04-01

260

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

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Full Text Available Abstract Background 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. Methods Confluent monolayers of Lulo cells were incubated with promastigotes and adhesion was assessed using both light microscopy and scanning electron microscopy. Findings 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. Conclusions We present evidence that Lulo cells can be useful in studies of insect-parasite interactions for Leishmania species.

Côrtes Luzia MC

2011-11-01

 
 
 
 
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USE OF THE POLYMERASE CHAIN REACTION FOR THE DIAGNOSIS OF ASYMPTOMATIC Leishmania INFECTION IN A VISCERAL LEISHMANIASIS-ENDEMIC AREA / Uso da reação em cadeia da polimerase para o diagnóstico de infecção assintomática por Leishmania em área endêmica de leishmaniose visceral  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese O diagnóstico de infecção assintomática por Leishmania (Leishmania) chagasi tem assumido crescente importância nos últimos anos. A expansão da leishmaniose visceral pode estar associada a outras vias de transmissão tais como transfusional, congênita, ou mesmo vetorial, sendo os indivíd [...] uos com infecção assintomática, potenciais reservatórios. Ademais, a identificação da infecção poderia auxiliar na condução dos pacientes com condições de imunossupressão (HIV, transplante, uso de imunomoduladores) e na avaliação da efetividade das medidas de controle. Neste estudo, foram avaliados clinicamente 149 indivíduos residentes em área endêmica de leishmaniose visceral e realizada a reação em cadeia da polimerase (PCR) gênero-específica, testes sorológicos e teste de Montenegro. Destes, 49 (32,9%) apresentaram PCR positiva, dos quais nenhum evoluiu com clínica de leishmaniose visceral nos três anos subsequentes. Não houve associação entre o resultado da PCR, dos exames sorológicos e do teste cutâneo. A positividade da PCR em indivíduos da área endêmica estudada não indicou risco de progressão para leishmaniose visceral e também não foi associada à maior positividade dos testes sorológicos. Abstract in english The diagnosis of asymptomatic infection with Leishmania (Leishmania) chagasi has become more important over recent years. Expansion of visceral leishmaniasis might be associated with other routes of transmission such as transfusion, congenital or even vector transmission, and subjects [...] with asymptomatic infection are potential reservoirs. Moreover, the identification of infection may contribute to the management of patients with immunosuppressive conditions (HIV, transplants, use of immunomodulators) and to the assessment of the effectiveness of control measures. In this study, 149 subjects living in a visceral leishmaniasis endemic area were evaluated clinically and submitted to genus-specific polymerase chain reaction (PCR), serological testing, and the Montenegro skin test. Forty-nine (32.9%) of the subjects had a positive PCR result and none of them developed the disease within a follow-up period of three years. No association was observed between the results of PCR, serological and skin tests. A positive PCR result in subjects from the endemic area did not indicate a risk of progression to visceral leishmaniasis and was not associated with a positive result in the serological tests.

Luciana Almeida, Silva; Héctor Dardo, Romero; Aline, Fagundes; Nédia, Nehme; Otávio, Fernandes; Virmondes, Rodrigues; Roberto Teodoro, Costa; Aluízio, Prata.

262

Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs / Leishmaniose visceral canina causada por Leishmania (L.) infantum chagasi na Amazônia brasileira: comparação da densidade parasitária da pele, linfonodo e vísceras entre cães soropositivos, sintomáticos e assintomáticos  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese A leishmaniose visceral canina (LVC) é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte i [...] mportante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA). Neste estudo foram examinados 51 cães com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de Leishmania (L.) infantum chagasi, na pele, linfonodo poplíteo e vísceras (fígado e baço) foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG). Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X²) e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p 0,05) na densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²) e do linfonodo (6,3/mm² x 8,3/mm²) entre cães assintomáticos e sintomáticos. Entretanto, a densidade de macrófagos infectados da víscera de cães sintomáticos (5,3/mm²) foi maior (p Abstract in english Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyi [...] a longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p

Luciana Vieira R., Lima; Liliane Almeida, Carneiro; Marliane Batista, Campos; Eujênia Janis, Chagas; Márcia D., Laurenti; Carlos E.P., Corbett; Ralph, Lainson; Fernando Tobias, Silveira.

2010-10-01

263

Immunoperoxidase technique using an anti-Leishmania (L.) chagasi hyperimmune serum in the diagnosis of culture-confirmed American tegumentary leishmaniasis / Técnica da imunoperoxidase utilizando um soro hiperimune anti-Leishmania (L.) chagasi no diagnóstico da leishmaniose tegumentar americana confirmada por cultura  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese O presente estudo relata a produção do soro policlonal de coelho anti-Leishmania (L.) chagasi, a padronização da técnica de imunohistoquímica (IHQ) e sua aplicação em lesões de leishmaniose cutânea (LC) diagnosticadas por isolamento de Leishmania sp. em cultura. Foram examinados 30 fragmentos de les [...] ões ativas de LC e 10 fragmentos de lesões de etiologia fúngica, utilizados como grupo controle. A IHQ mostrou-se mais sensível na detecção de amastigotas que a coloração em hematoxilina-eosina (HE), sendo positiva em 24 fragmentos de LC (80%) e ao passo que a HE foi positiva em 16 (53%) (p = 0,028). A IHQ também marcou diferentes espécies de fungos causadoras de micoses cutâneas. Adicionalmente, verificou-se positividade no citoplasma de células mononucleares e células endoteliais. Entretanto, esse achado esteve presente no grupo controle. Conclui-se que o método de IHQ apresentou boa sensibilidade na detecção de formas amastigotas. Abstract in english The present study reports the production of the rabbit anti-Leishmania (L.) chagasi hyperimmune serum, the standardization of the immunohistochemistry (IHC) technique and the evaluation of its employment in cutaneous leishmaniasis (CL) lesions diagnosed by Leishmania sp. culture isolation. Thirty fr [...] agments of active CL lesions were examined as well as 10 fragments of cutaneous mycosis lesions as control group. IHC proved more sensitive in detecting amastigotes than conventional hematoxylin-eosin (HE) stained slides: the former was positive in 24 (80%) biopsies whereas the latter, in 16 (53%) (p = 0.028). The reaction stained different fungus species causing cutaneous mycosis. Besides, positive reaction was noticed in mononuclear and endothelial cells. Nevertheless, this finding was present in the control group biopsies. It is concluded that IHC showed good sensitivity in detecting amastigotes.

Leonardo P., Quintella; Tullia, Cuzzi; Maria de F., Madeira; Thais, Okamoto; Armando de O., Schubach.

2009-04-01

264

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

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American cutaneous leishmaniasis includes a spectrum of clinical forms localized cutaneous, diffuse cutaneous, and mucocutaneous leishmaniasis which can be caused by different strains of Leishmania belonging to the L. mexicana or L. braziliensis complexes which may coexist in the same endemic area. We evaluated the PCR-RFLP assay of the ITS1 genes for direct identification of Leishmania species in 163 clinical samples and 21 Mexican isolates of Leishmania. In relation to the Mexican isolates of Leishmania 52% displayed a pattern similar to the L. (L.) mexicana, 5% showed a mixed pattern compatible with L. (L.) mexicana and L. (V.) braziliensis, eight with L. (L.) amazonensis and L. (L.) mexicana, and one to L. (V.) braziliensis. Most of the clinical samples, 109/116 (94%), gave a pattern similar to that of the L. mexicana, two clinical samples gave similar patterns to that of Leishmania braziliensis, and 5 samples gave patterns that suggest a coinfection of L. (L.) mexicana and L. (V.) braziliensis or L. (L.) mexicana and L. (L.) amazonensis. The ITS1 PCR-RFLP assay is a multipurpose tool for diagnosis of Leishmania from clinical samples and enables determination of the infecting species of New World Leishmania in the field in relatively short time and low cost. PMID:25104958

Monroy-Ostria, Amalia; Nasereddin, Abedelmajeed; Monteon, Victor M; Guzmán-Bracho, Carmen; Jaffe, Charles L

2014-01-01

265

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

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American cutaneous leishmaniasis includes a spectrum of clinical forms localized cutaneous, diffuse cutaneous, and mucocutaneous leishmaniasis which can be caused by different strains of Leishmania belonging to the L. mexicana or L. braziliensis complexes which may coexist in the same endemic area. We evaluated the PCR-RFLP assay of the ITS1 genes for direct identification of Leishmania species in 163 clinical samples and 21 Mexican isolates of Leishmania. In relation to the Mexican isolates of Leishmania 52% displayed a pattern similar to the L. (L.) mexicana, 5% showed a mixed pattern compatible with L. (L.) mexicana and L. (V.) braziliensis, eight with L. (L.) amazonensis and L. (L.) mexicana, and one to L. (V.) braziliensis. Most of the clinical samples, 109/116 (94%), gave a pattern similar to that of the L. mexicana, two clinical samples gave similar patterns to that of Leishmania braziliensis, and 5 samples gave patterns that suggest a coinfection of L. (L.) mexicana and L. (V.) braziliensis or L. (L.) mexicana and L. (L.) amazonensis. The ITS1 PCR-RFLP assay is a multipurpose tool for diagnosis of Leishmania from clinical samples and enables determination of the infecting species of New World Leishmania in the field in relatively short time and low cost. PMID:25104958

Monroy-Ostria, Amalia; Nasereddin, Abedelmajeed; Monteon, Victor M.; Guzman-Bracho, Carmen; Jaffe, Charles L.

2014-01-01

266

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

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

Rafael Antonio do Nascimento Ramos

2012-09-01

267

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

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

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

2012-09-01

268

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

Scientific Electronic Library Online (English)

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

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

269

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

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

Albino Verçosa de Magalhães

1986-10-01

270

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

Science.gov (United States)

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

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

2012-03-01

271

Identification of Leishmania chagasi from skin in Leishmania/HIV co-infection: a case report Identificação de Leishmania chagasi na pele em co-infecção Leishmania/HIV: relato de caso  

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Full Text Available A case of HIV/Leishmania co-infection presenting both visceral and cutaneous manifestations is reported. Leishmania infection was confirmed by conventional methods (parasitological approach and serology and by PCR. Leishmania chagasi isolated from the skin lesion was characterized by enzyme electrophoresis and by restriction fragment length polymorphism of the internal transcribed spacer of the ribosomal gene.É descrito um caso de co-infecção leishmania/HIV com manifestações cutâneas e visceral. Infecção pela leishmania foi confirmada através de métodos convencionais (parasitológicos e sorológicos e através da PCR. A espécie Leishmania chagasi isolada da pele foi caracterizada por eletroforese enzimática e por polimorfismo de fragmento obtido por enzima de restrição.

Marcela Orsini

2002-06-01

272

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in portuguese A leishmaniose é considerada uma importante causa de morbidade e mortalidade a nível mundial, principalmente nos países tropicais. As formas cutânea e mucocutânea são causadas, entre outras espécies, por Leishmania braziliensis. Na procura de compostos leishmanicidas de origem natural, foi estudada [...] a atividade da mistura de alcalóides de Ervatamia coronaria (Apocynaceae) contra amastigotas de L. braziliensis em 6 concentrações diferentes (1, 10, 20, 25, 50 e 100 µg/mL). Foram tratados macrófagos de ratos da linha J774, infectados com promastigotas de L. braziliensis, com a mistura de alcalóides 1 hora após-infecção e diariamente por 3 dias sem mudança de meio. As experiências de citotoxicidade foram efetuadas sobre os macrófagos com azul tripam. Todos os cultivos foram feitos de forma triplicada e os grupos de controle não foram submetidos à mistura de alcalóides. Foi obtido que o composto adicionado exerce atividade doses/dependente sobre a parasita. No entanto, as concentrações mais altas (50 e 100 µg/mL), adicionado durante 3 dias, mostraram os maiores índices de infecção, provavelmente devido a diminuição no número de macrófagos, sobre os quais não foi observado efeito tóxico do tratamento durante 24 horas DL50/24h = 233,52 µg/mL. Os resultados dessa pesquisa revelaram uma nova atividade farmacológica de alcalóides da espécie Ervatamia coronaria sobre a forma amastigota de Leishmania braziliensis, com IC50 = 2,6 e 12,4 µg/mL sem mostrar toxicidade sobre a célula hospedeira. Abstract in spanish [...] Abstract in english Leishmaniasis, caused by Leishmania sp., is one of the mean reason of considerable mortality and morbidity throughout the world, especially in the tropics. Cutaneous and mucocutaneous manifestations are caused by Leishmania braziliensis, and the cutaneous form is the most common one in Colombia. In [...] the search for antileishmanial compounds from natural sources, we studied the alkaloids mixture from Ervatamia coronaria against L. braziliensis at six different concentrations (1.0, 10, 20, 25, 50 and 100 µg/mL). Macrophages J774 infected with L. braziliensis were treated with alkaloids one hour, and once a day for three days, after parasitic infection and preserving the same culture medium. Cytotoxicity with trypan blue was undertaken in macrophages J774 by using the same concentrations. Three different cultures samples were carried out. As a control we used medium alone. The alkaloids mix showed a dose/dependent activity on amastigote, but by increasing concentrations from 50 to 100 µg/mL for three days, we saw a high index of infection, probably caused by cellular death. We did not see any toxic effect on macrophages J774 at 100 µg/mL, LD50/24h= 233.52 µg/mL. These results revealed a novel pharmacological activity of alkaloids from E. coronaria against amastigotes of L. braziliensis IC50 = 2.6 and 12.4 µg/mL without toxicity on host cells.

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

273

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in portuguese A leishmaniose é considerada uma importante causa de morbidade e mortalidade a nível mundial, principalmente nos países tropicais. As formas cutânea e mucocutânea são causadas, entre outras espécies, por Leishmania braziliensis. Na procura de compostos leishmanicidas de origem natural, foi estudada [...] a atividade da mistura de alcalóides de Ervatamia coronaria (Apocynaceae) contra amastigotas de L. braziliensis em 6 concentrações diferentes (1, 10, 20, 25, 50 e 100 µg/mL). Foram tratados macrófagos de ratos da linha J774, infectados com promastigotas de L. braziliensis, com a mistura de alcalóides 1 hora após-infecção e diariamente por 3 dias sem mudança de meio. As experiências de citotoxicidade foram efetuadas sobre os macrófagos com azul tripam. Todos os cultivos foram feitos de forma triplicada e os grupos de controle não foram submetidos à mistura de alcalóides. Foi obtido que o composto adicionado exerce atividade doses/dependente sobre a parasita. No entanto, as concentrações mais altas (50 e 100 µg/mL), adicionado durante 3 dias, mostraram os maiores índices de infecção, provavelmente devido a diminuição no número de macrófagos, sobre os quais não foi observado efeito tóxico do tratamento durante 24 horas DL50/24h = 233,52 µg/mL. Os resultados dessa pesquisa revelaram uma nova atividade farmacológica de alcalóides da espécie Ervatamia coronaria sobre a forma amastigota de Leishmania braziliensis, com IC50 = 2,6 e 12,4 µg/mL sem mostrar toxicidade sobre a célula hospedeira. Abstract in spanish [...] Abstract in english Leishmaniasis, caused by Leishmania sp., is one of the mean reason of considerable mortality and morbidity throughout the world, especially in the tropics. Cutaneous and mucocutaneous manifestations are caused by Leishmania braziliensis, and the cutaneous form is the most common one in Colombia. In [...] the search for antileishmanial compounds from natural sources, we studied the alkaloids mixture from Ervatamia coronaria against L. braziliensis at six different concentrations (1.0, 10, 20, 25, 50 and 100 µg/mL). Macrophages J774 infected with L. braziliensis were treated with alkaloids one hour, and once a day for three days, after parasitic infection and preserving the same culture medium. Cytotoxicity with trypan blue was undertaken in macrophages J774 by using the same concentrations. Three different cultures samples were carried out. As a control we used medium alone. The alkaloids mix showed a dose/dependent activity on amastigote, but by increasing concentrations from 50 to 100 µg/mL for three days, we saw a high index of infection, probably caused by cellular death. We did not see any toxic effect on macrophages J774 at 100 µg/mL, LD50/24h= 233.52 µg/mL. These results revealed a novel pharmacological activity of alkaloids from E. coronaria against amastigotes of L. braziliensis IC50 = 2.6 and 12.4 µg/mL without toxicity on host cells.

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

2008-09-01

274

Morphological and physiological changes in Leishmania promastigotes induced by yangambin, a lignan obtained from Ocotea duckei.  

Science.gov (United States)

We have previously demonstrated that yangambin, a lignan obtained from Ocotea duckei Vattimo (Lauraceae), shows antileishmanial activity against promastigote forms of Leishmania chagasi and Leishmania amazonensis. The aim of this study was to determine the in vitro effects of yangambin against these parasites using electron and confocal microscopy. L. chagasi and L. amazonensis promastigotes were incubated respectively with 50 ?g/mL and 65 ?g/mL of pure yangambin and stained with acridine orange. Treated-parasites showed significant alterations in fluorescence emission pattern and cell morphology when compared with control cells, including the appearance of abnormal round-shaped cells, loss of cell motility, nuclear pyknosis, cytoplasm acidification and increased number of acidic vesicular organelles (AVOs), suggesting important physiological changes. Ultrastructural analysis of treated-promatigotes showed characteristics of cell death by apoptosis as well as by autophagy. The presence of parasites exhibiting multiples nuclei suggests that yangambin may also affect the microtubule dynamic in both Leishmania species. Taken together our results show that yangambin is a promising agent against Leishmania. PMID:20691682

Monte Neto, Rubens L; Sousa, Louisa M A; Dias, Celidarque S; Barbosa Filho, José M; Oliveira, Márcia R; Figueiredo, Regina C B Q

2011-01-01

275

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

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

Cardoso, Andre Gustavo Tempone

1999-07-01

276

Molecular characterization of the MRPA transporter and antimony uptake in four New World Leishmania spp. susceptible and resistant to antimony.  

Science.gov (United States)

ATP-binding cassette (ABC) transporters have been associated with drug resistance in various diseases. The MRPA gene, a transporter of ABCC subfamily, is involved in the resistance by sequestering metal-thiol conjugates in intracellular vesicles of Leishmania parasite. In this study, we performed the molecular characterization of the MRPA transporter, analysis of P-glycoprotein (Pgp) and aquaglyceroporin-1 (AQP1) expression, and determination of antimony level in antimony-susceptible and -resistant lines of L. (V.) guyanensis, L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) infantum. PFGE analysis revealed an association of chromosomal amplification of MRPA gene with the drug resistance phenotype in all SbIII-resistant Leishmania lines analyzed. Levels of mRNA from MRPA gene determined by real-time quantitative RT-PCR showed an increased expression of two fold in SbIII-resistant lines of Leishmania guyanensis, Leishmania amazonensis and Leishmania braziliensis. Western blot analysis revealed that Pgp is increased in the SbIII-resistant L. guyanensis and L. amazonensis lines. The intracellular level of antimony quantified by graphite furnace atomic absorption spectrometry showed a reduction in the accumulation of this element in SbIII-resistant L. guyanensis, L. amazonensis and L. braziliensis lines when compared to their susceptible counterparts. Interestingly, a down-regulation of AQP1 protein was observed in the SbIII-resistant L. guyanensis and L. amazonensis lines, contributing for decreasing of SbIII entry in these lines. In addition, efflux experiments revealed that the rates of SbIII efflux are higher in the SbIII-resistant lines of L. guyanensis and L. braziliensis, that may explain also the low SbIII concentration within of these parasites. The BSO, an inhibitor of ?-glutamylcysteine synthetase enzyme, reversed the SbIII-resistance phenotype of L. braziliensis and caused an increasing in the Sb intracellular level in the LbSbR line. Our data indicate that the mechanisms of antimony-resistance are different among species of Leishmania analyzed in this study. PMID:24533304

Moreira, Douglas S; Monte Neto, Rubens L; Andrade, Juvana M; Santi, Ana Maria M; Reis, Priscila G; Frézard, Frédéric; Murta, Silvane M F

2013-12-01

277

Activity of Brazilian and Bulgarian propolis against different species of Leishmania  

Scientific Electronic Library Online (English)

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

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

278

Activity of Brazilian and Bulgarian propolis against different species of Leishmania  

Scientific Electronic Library Online (English)

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

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

2007-02-01

279

Activity of Brazilian and Bulgarian propolis against different species of Leishmania  

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

Gérzia Maria de Carvalho Machado

2007-02-01

280

Mucosal Leishmaniasis Caused by Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in the Brazilian Amazon  

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Background Leishmania (Viannia) braziliensis is a parasite recognized as the most important etiologic agent of mucosal leishmaniasis (ML) in the New World. In Amazonia, seven different species of Leishmania, etiologic agents of human Cutaneous Leishmaniasis, have been described. Isolated cases of ML have been described for several different species of Leishmania: L. (V.) panamensis, L. (V.) guyanensis and L. (L.) amazonensis. Methodology Leishmania species were characterized by polymerase chain reaction (PCR) of tissues taken from mucosal biopsies of Amazonian patients who were diagnosed with ML and treated at the Tropical Medicine Foundation of Amazonas (FMTAM) in Manaus, Amazonas state, Brazil. Samples were obtained retrospectively from the pathology laboratory and prospectively from patients attending the aforementioned tertiary care unit. Results This study reports 46 cases of ML along with their geographical origin, 30 cases caused by L. (V.) braziliensis and 16 cases by L. (V.) guyanensis. This is the first record of ML cases in 16 different municipalities in the state of Amazonas and of simultaneous detection of both species in 4 municipalities of this state. It is also the first record of ML caused by L. (V.) guyanensis in the states of Pará, Acre, and Rondônia and cases of ML caused by L. (V.) braziliensis in the state of Rondônia. Conclusions/Significance L. (V.) braziliensis is the predominant species that causes ML in the Amazon region. However, contrary to previous studies, L. (V.) guyanensis is also a significant causative agent of ML within the region. The clinical and epidemiological expression of ML in the Manaus region is similar to the rest of the country, although the majority of ML cases are found south of the Amazon River. PMID:21408116

de Oliveira Guerra, Jorge Augusto; Prestes, Suzane Ribeiro; Silveira, Henrique; Coelho, Leila Inês de Aguiar Raposo Câmara; Gama, Pricila; Moura, Aristoteles; Amato, Valdir; Barbosa, Maria das Graças Vale; de Lima Ferreira, Luiz Carlos

2011-01-01

 
 
 
 
281

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

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

Felipe Wartchow

2012-06-01

282

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

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

T. G. V. Silveira

1995-06-01

283

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

Scientific Electronic Library Online (English)

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

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

1995-06-01

284

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

Scientific Electronic Library Online (English)

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

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

285

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

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

L. Ryan

1987-09-01

286

Methylglyoxal metabolism in Leishmania infantum  

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Leishmanioses são doenças que afectam humanos e outros mamíferos, provocadas por um parasita do género Leishmania, pertencente à família Trypanosomatidae. A forma mais severa da doença é letal se não for tratada, não existindo actualmente vacinas ou terapias curativas eficazes. A identificação de novos alvos terapêuticos baseia-se em diferenças encontradas entre o parasita e o hospedeiro. Uma das principais características bioquímicas que distingue os tripanossomat...

Barata, Li?dia Isabel Sebastia?o

2010-01-01

287

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

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

Carlos Eduardo Ribeiro, Coutinho; Dilvani Oliveira, Santos; Cibele, Baptista; Fabiano Borges, Figueiredo; Maria de Fatima, Madeira.

288

Canine visceral leishmaniasis due to Leishmania (L. infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs Leishmaniose visceral canina causada por Leishmania (L. infantum chagasi na Amazônia brasileira: comparação da densidade parasitária da pele, linfonodo e vísceras entre cães soropositivos, sintomáticos e assintomáticos  

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Full Text Available Canine visceral leishmaniasis (CVL is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL. In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L. infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG. Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p 0.05 in the skin (10.7/mm² x 15.5/mm² and lymph node (6.3/mm² x 8.3/mm², between asymptomatic and symptomatic dogs, respectively. It was higher (p A leishmaniose visceral canina (LVC é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte importante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA. Neste estudo foram examinados 51 cães com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de Leishmania (L. infantum chagasi, na pele, linfonodo poplíteo e vísceras (fígado e baço foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG. Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X² e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p 0,05 na densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm² e do linfonodo (6,3/mm² x 8,3/mm² entre cães assintomáticos e sintomáticos. Entretanto, a densidade de macrófagos infectados da víscera de cães sintomáticos (5,3/mm² foi maior (p < 0,05 que a de cães assintomáticos (1,4/mm². Estes resultados sugerem, fortemente, que cães naturalmente infectados por L. (L. i. chagasi, assintomáticos ou sintomáticos, podem servir como fonte de infecção, principalmente, considerando-se que a densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm², local onde o flebotomíneo vetor Lu. longipalpis realiza a hematofagia, foi maior (p < 0,05 que as do linfonodo (6,3/mm² x 8.3/mm² e vísceras (1,4/mm²x 5,3/mm².

Luciana Vieira R. Lima

2010-10-01

289

Variabilidad de Leishmania (Leishmania) infantum en España  

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En este trabajo nos planteamos como objetivo principal estudiar la variabilidad de Leishmania (leishmania) infantum y las implicaciones de la misma en la epidemiología de la leishmaniosis en España. Dada la importancia que la asociación lv/vih tiene en nuestro país y con el fin de determinar si los parásitos aislados en esta asociación comparten las mismas características biológicas que aquellas responsables de las leishmaniosis habituales, hemos estudiado mediante análisis enzimáti...

Jime?nez Alonso, Mari?a Isabel

1994-01-01

290

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

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

Trícia Maria Ferreira de Sousa Oliveira

2011-03-01

291

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

Scientific Electronic Library Online (English)

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

Trícia Maria Ferreira de Sousa, Oliveira; Elton José Rosas de, Vasconcelos; Andréa Cristina Higa, Nakaghi; Tânia Paula Aquino, Defina; Márcia Mariza Gomes, Jusi; Cristiane Divan, Baldani; Ângela Kaysel, Cruz; Rosangela Zacarias, Machado.

2011-03-01

292

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

Scientific Electronic Library Online (English)

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

Trícia Maria Ferreira de Sousa, Oliveira; Elton José Rosas de, Vasconcelos; Andréa Cristina Higa, Nakaghi; Tânia Paula Aquino, Defina; Márcia Mariza Gomes, Jusi; Cristiane Divan, Baldani; Ângela Kaysel, Cruz; Rosangela Zacarias, Machado.

293

Leishmania-Mediated Inhibition of Iron Export Promotes Parasite Replication in Macrophages  

Science.gov (United States)

Leishmania parasites infect macrophages, cells that play an important role in organismal iron homeostasis. By expressing ferroportin, a membrane protein specialized in iron export, macrophages release iron stored intracellularly into the circulation. Iron is essential for the intracellular replication of Leishmania, but how the parasites compete with the iron export function of their host cell is unknown. Here, we show that infection with Leishmania amazonensis inhibits ferroportin expression in macrophages. In a TLR4-dependent manner, infected macrophages upregulated transcription of hepcidin, a peptide hormone that triggers ferroportin degradation. Parasite replication was inhibited in hepcidin-deficient macrophages and in wild type macrophages overexpressing mutant ferroportin that is resistant to hepcidin-induced degradation. Conversely, intracellular growth was enhanced by exogenously added hepcidin, or by expression of dominant-negative ferroportin. Importantly, dominant-negative ferroportin and macrophages from flatiron mice, a mouse model for human type IV hereditary hemochromatosis, restored the infectivity of mutant parasite strains defective in iron acquisition. Thus, inhibition of ferroportin expression is a specific strategy used by L. amazonensis to inhibit iron export and promote their own intracellular growth. PMID:24497831

Ben-Othman, Rym; Flannery, Andrew R.; Miguel, Danilo C.; Ward, Diane M.; Kaplan, Jerry; Andrews, Norma W.

2014-01-01

294

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

Scientific Electronic Library Online (English)

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

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

295

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

Scientific Electronic Library Online (English)

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

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

2006-06-01

296

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

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

Yeda L. Nogueira

2006-06-01

297

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

Scientific Electronic Library Online (English)

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

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

298

Tunicamycin-resistant variants from five species of Leishmania contain amplified DNA in extrachromosomal circles of different sizes with a transcriptionally active homologous region.  

Science.gov (United States)

Twelve independent variants were selected from five species of Leishmania for resistance to tunicamycin by exposure of cultured promastigotes to increasing concentrations of this antibiotic, an inhibitor of the microsomal N-acetylglucosamine-1-phosphate transferase in the dolichol pathway of N-glycosylation. All variants obtained from all species, as found previously with Leishmania amazonensis, contain amplified chromosomal DNA exclusively as extrachromosomal circles. These circular amplicons hybridize with amplified DNAs cloned previously from tunicamycin-resistant Leishmania amazonensis, but not with those from Leishmania resistant to other drugs. The amplicons from tunicamycin-resistant cells vary with different species in size from 30 to 70 kb, but all share a homologous region of 20 kb. Multiple independent transcripts are overexpressed from this region. Elevation of the microsomal glycosyltransferase activity is demonstrated in these variants from representative species. The results thus provide further evidence that this enzyme is overexpressed due to amplification of the gene in these cells. The consistent observation of this event in all cases studied also suggests that this is the predominant, if not the only mechanism of tunicamycin resistance in Leishmania. PMID:1646959

Katakura, K; Peng, Y; Pithawalla, R; Detke, S; Chang, K P

1991-02-01

299

Palaearctic origin of Leishmania  

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The hypothesis of a Palaearctic origin of Leishmania in the early Cenozoic, dispersal to the Nearctic in the late Eocene and to the Neotropical in the Pliocene is presented. It is further hypothesized that murid rodents and their immediate ancestors have been important mammalian reservoirs since the origination of Leishmania. Biochemical, molecular, biogeographical, entomological, mammalalogical and ecological support for these hypotheses are reviewed.

Kerr Sara F

2000-01-01

300

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

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

MF Madeira

1999-09-01

 
 
 
 
301

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

Science.gov (United States)

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

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

2014-07-01

302

Immunocytochemical identification of leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies  

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Full Text Available The unlabelled antibody peroxidase-antiperoxidase method was used to study the immunocytochemical properties of Leishmania and Trypanosoma cruzi amastigotes in situ after tissues had been submitted to different fixation procedures. Antisera were obtained from rabbits chronically infected with different strains of T. cruzi or immunized with L. mexicana amazonensis and L. braziliensis guyanensis, and were applied on 5 µm thick sections. T. cruzi antigens were well stained by the three anti-T. cruzi sera and the two anti-heis.hmama.sera at optimum dilution between 1:1,000 and 1:2,000, regardless the parasite strain. Differently, the leishmanial antigens were revealed by Leishmania sera only at low dilutions (between 1:60 -1:160, whereas the anti-T. cruzi sera, at these low dilutions, gave rather weak stainings. Although there is no clear explanation for this immunocytochemical "reverse-monodirectional" cross-reactivity between Leishmania and T. cruzi, the present results show that polyclonal antibodies agains Leishmania species, when used for immunocytochemical detection of these parasites in situ, react more strongly with T. cruzi amastigotes than with the homologous amastigotes.O método daperoxidase-antiperoxidase foi utilizado para estudar as propriedades imunocitoquimicas de Leishmanias e de amastigotas do Trypanosoma cruzi, in situ, após os tecidos terem sido submetidos a diferentes tipos de fixação. Anti-soros foram obtidos de coelhos cronicamente infectados com três cepas de T. cruzi ou imunizados com L. mexicana ámazonensis e L. braziliensis guyanensis e aplicados nos cortes histológicos de 5 µm de espessura. Os antígenos de T. cruzi foram corados muito bem pelos três soros anti-T. cruzi e pelos dois soros anti-Leishmania com diluições entre 1:1.000 e 1:2.000. Diferentemente, os antígenos dç Leishmania foram revelados pelos soros anti- Leishmania somente em baixas diluições, ou seja, entre 1:60 e 1:160 enquanto que os soros anti-T. cruzi, mesmo nestas diluições baixas,