Kinetoplastid Biology and Disease

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. Background Leishmania is an intracellular protozoan parasite that infects humans and causes a wide spectrum of diseases known as leishmaniases. Leishmaniases are endemic in 88 countries, where 350 million people live the risk of infection. In the American continent, leishmaniasis is caused by a different number of species and infection with L. amazonensis, in particular, produces a wide spectrum of clinical diseases [1]. Severity varies from localized cutaneous leishmaniasis (LCL), the most common clinical manifestation, to diffuse cutaneous leishmaniasis (DCL). LCL, in Brazil, is associated with species belonging to both Published: 21 June 2007 Kinetoplastid Biology and Disease 2007, 6:5 doi:10.1186/1475-9292-6-5 Received: 23 November 2006 Accepted: 21 June 2007 This article is available from: http://www.kinetoplastids.com/content/6/1/5 © 2007 de Oliveira et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.