Resumo

CARDENAS ALEGRIA, Óscar V. et al. Analysis of molecular markers for typing of Leishmania spp. parasites circulating in La Paz department, Bolivia. BIOFARBO [online]. 2012, vol.20, n.1, pp. 8-21. ISSN 1813-5363.

The identification and characterization of species of Leishmania parasites is complex, due to genetic similitude among them. However, molecular techniques have simplified this analysis. In this study, we evaluated the amplification of kinetoplast molecular markers amplified from minicircles (13A/13B), maxicircles (cytochrome b), and chromosomal sequencing (7SL RNA) using different strains of the Leishmania and Crithidia genera. The amplification of the cytochrome b segment differentiated the Leishmania and Crithidia genera. Genetic sequencing of the 7SL RNA fragment permitted observation of similarities between these parasites as well as phylogenetic tree construction, which made it possible to organize the Leishmania parasites at the subgenus and complex level, but no intra-species differentiation was found. The sequencing analysis of the nine strains of Leishmania, isolated from skin ulcers of patients from different endemic regions of the La Paz department in Bolivia, identified five strains among the Leishmania (V) braziliensis complex type and four strains within the Leishmania (L) mexicana complex type. The use of this molecular method allows the differentiation of the circulating strains of Leishmania parasites, and it is therefore a useful tool to update the epidemiology of this parasitosis.

Palavras-chave : Crithidia; Leishmania; typing; molecular markers; 13A/13B; 7SL RNA; Cytochrome b.