This study was designed to assess in vitro metacyclogenesis of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis clinical field isolates obtained from patient lesions (L. braziliensis IMG3 and PPS6m; L. amazonensis MAB6). Metacyclogenesis was evaluated by different criteria, namely, promastigote size (morphometric analysis and flow cytometry), surface modifications (loss...

Previous results demonstrate that the hybrid synthetic pterocarpanquinone LQB-118 presents antileishmanial activity against Leishmania amazonensis in a mouse model. The aim of the present study was to use a hamster model to investigate whether LQB-118 presents antileishmanial activity against Leishmania (Viannia) braziliensis, which is the major Leishmania species related to American tegumentar...

Leishmania braziliensis and Leishmania amazonensis are both causative agents of cutaneous leishmaniasis in South America. However, patient prognosis and the host immune response differ considerably depending on the infecting parasite species. The mechanisms underlying these differences appear to be multifactorial, with both host and parasite components contributing to disease outcome. As neutro...

It was recently hypothesized that Leishmania amastigotes could constitute a semi-quiescent stage characterized by low replication and reduced metabolic activity. This concept developed with Leishmania (Leishmania) mexicana and Leishmania (Leishmania) major models might explain numerous clinical and sub-clinical features of Leishmania (Viannia) braziliensis infections, like reactivation of the d...

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 reactivi...

Leishmania (Viannia) braziliensis control and tissue damage relate to the effector immune response, which in turn affects clinical outcome. Leishmania reactive CD4(+) and CD8(+) T cells are expanded in long-term healed cutaneous leishmaniasis (hCL) patients but their functional characteristics remain to be determined. This study investigates antigen-specific recall in long-term healed CL caused...

In Colombia, the cutaneous leishmaniasis (CL) is the most common manifestation across the army personnel. Hence, it is mandatory to determine the species associated with the disease as well as the association with the clinical traits. A total of 273 samples of male patients with CL were included in the study and clinical data of the patients was studied. PCR and sequencing analyses (Cytb and HS...

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) amazon...

In the sand-fly mid gut, Leishmania promastigotes are exposed to acute changes in nutrients, e.g. amino acids (AAs). These metabolites are the main energy sources for the parasite, crucial for its differentiation and motility. We analysed the migratory behaviour and morphological changes produced by aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing AAs in Leishmania a...

The natural infection of sand flies by Leishmania was examined in the Department of Huanuco of Peru, where cutaneous leishmaniasis caused by a hybrid of Leishmania (Viannia) braziliensis/L. (V.) peruviana is endemic. A total of 2,997 female sand flies were captured by CDC light traps and Shannon traps, of which 2,931 and 66 flies were identified as Lutzomyia tejadai and Lu fischeri, respectivel...