A dysflagellar mutant of Leishmania (Viannia) braziliensis isolated from a cutaneous leishmaniasis patient

<p>Abstract</p> <p>Background</p> <p>Parasites of the <it>Leishmania </it>genus alternate between the flagellated extracellular promastigote stage and intracellular amastigotes. Here we report the characterization of a <it>Leishmania </it>isolate, obtained from a cutaneous leishmaniasis patient, which presents peculiar morphological features.</p> <p>Methods</p> <p>The parasite was cultured <it>in vitro </it>and characterized morphologically using optical and electron microscopy. Identification was performed based on monoclonal antibodies and internal ribosomal spacer typing. <it>In vitro </it>macrophage cultures, murine experimental models and sand fly infections were used to evaluate infectivity <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p>The isolate was identified as <it>Leishmania </it>(<it>Viannia</it>) <it>braziliensis</it>. In the atypical promastigotes grown in culture, a short flagellum surrounded or interrupted by a protuberance of disorganized material was observed. A normal axoneme was present close to the basal body but without elongation much further outside the flagellar pocket. A disorganized swelling at the precocious end of the axoneme coincided with the lack of a paraflagellar rod structure. The isolate was able to infect macrophages <it>in vitro</it>, induce lesions in BALB/c mice and infect <it>Lutzomyia longipalpis</it>.</p> <p>Conclusions</p> <p>Notwithstanding the lack of an extracellular flagellum, this isolate infects macrophages <it>in vitro </it>and produces lesions when inoculated into mice. Moreover, it is able to colonize phlebotomine sand flies. Considering the importance attributed to the flagellum in the successful infection and survival of <it>Leishmania </it>in the insect midgut and in the invasion of macrophages, these findings may bring new light into the infectious mechanisms of <it>L</it>. (<it>V</it>.) <it>braziliensis</it>.</p

In vitro sensitivity of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis Brazilian isolates to meglumine antimoniate and amphotericin B

Resistance of Leishmania parasites to specific chemotherapy has become a well-documented problem in the Indian subcontinent in recent years but only a few studies have focused on the susceptibility of American Leishmania isolates. Our susceptibility assays to meglumine antimoniate were performed against intracellular amastigotes after standardizing an in vitro model of macrophage infection appropriate for Leishmania (Viannia) braziliensis isolates. For the determination of promastigote susceptibility to amphotericin B, we developed a simplified MTT-test. The sensitivity in vitro to meglumine antimoniate and amphotericin B of 13 isolates obtained from Brazilian patients was determined. L. (V.) braziliensis isolates were more susceptible to meglumine antimoniate than Leishmania (Leishmania) amazonensis. EC(50), EC(90) and activity indexes (calculated over the sensitivity of reference strains), suggested that all isolates tested were susceptible in vitro to meglumine antimoniate, and did not show association with the clinical outcomes. Isolates were also uniformly susceptible in vitro to amphotericin B.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effectiveness of an immunohistochemical protocol for Leishmania detection in different clinical forms of American tegumentary leishmaniasis

Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Rene Rachou. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brazil.Universidade Federal de Uberlândia. Instituto de Ciências Biomédicas. Departamento de Imunologia, Microbiologia e Parasitologia. Uberlândia, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Rene Rachou. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa=0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosi

Effectiveness of an immunohistochemical protocol for Leishmania detection in different clinical forms of American tegumentary leishmaniasis

Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Universidade Federal de Uberlândia. Instituto de Ciências Biomédicas. Departamento de Imunologia, Microbiologia e Parasitologia. Minas Gerais, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa = 0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosis

Effectiveness of an immunohistochemical protocol for Leishmania detection in different clinical forms of American tegumentary leishmaniasis

Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Universidade Federal de Goiás. Faculdade de Medicina. Instituto Goiano de Oncologia e Hematologia. Goiânia, GO, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Universidade Federal de Uberlândia. Instituto de Ciências Biomédicas. Departamento de Imunologia, Microbiologia e Parasitologia. Minas Gerais, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Patologia Geral. Belo Horizonte, MG, Brazil.American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa = 0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosis