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Document Type: Artigo
Title: Resistance of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis to nitric oxide correlates with disease severity in Tegumentary Leishmaniasis
Authors: Giudice, Ângela
Camada, Ilza
Leopoldo, Paulo de Tarso Gonçalves
Pereira, Júlia M. B.
Rilley, Lee
Wilson, Mary
Ho, John
Jesus, Amélia Maria Ribeiro de
Carvalho Filho, Edgar Marcelino de
Almeida, Roque Pacheco de
Issue Date: Feb-2007
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.
Keywords: Leishmania
Leishmania amazonensis
Leishmania braziliensis
Leishmaniose tegumentar
ISSN: 1471-2334
Publisher / Institution : BioMed Central
Citation: GIUDICE, A et al. Resistance of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis to nitric oxide correlates with disease severity in Tegumentary Leishmaniasis. BMC Infectious Diseases, v. 7, n. 7, fev. 2007. Disponível em: <>. Acesso em: 20 fev. 2014.
License: Creative Commons Attribution License
Appears in Collections:DME - Artigos publicados em periódicos

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