Original research

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

João Paulo C de Oliveira¹, Flora Fernandes¹, Angela K Cruz², Viviane Trombela², Elisângela Monteiro³, Anamaria A Camargo³, Aldina Barral¹ and Camila I de Oliveira¹

¹Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Rua Waldemar Falcão, 121, 40296-710, Salvador, BA, Brazil

²Faculdade de Medicina de Ribeirão Preto, USP, Av. Bandeirantes 3900, 14049-900, Ribeirão Preto, SP, Brazil

³Ludwig Institute for Cancer Research, R. Prof. Antonio Prudente, 109, 4th Floor, 01509-010, São Paulo, SP, Brazil

Kinetoplastid Biology and Disease 2007, 6:5doi:10.1186/1475-9292-6-5

Published:	21 June 2007

Abstract

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.