Aspectos da heterogeneidade genética de Leishmania (Leishmania) major-like isoladas no Brasil

Abstract

The World Health Organization (WHO) considers Leishmaniasis one of the most important health problems. Cutaneous leishmaniasis is widely distributed in the Old and New World. They are endemic on five continents, being registered in 98 countries and three territories, covering underdeveloped, developing or even developed countries, with prevalence in areas of temperate to tropical climate. It is estimated that around 14 million people are infected worldwide and 350 million are at risk of infection. In the New World, the species Leishmania L. (Leishmania) amazonensis, (L.) mexicana, L. (L.) venezuelensis, Leishmania (Viannia) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, L. (V.) peruviana and L. (L.) major in the Old World are the main species that cause cutaneous forms of leishmaniasis. However, in some countries of the American continent, such as Brazil, Venezuela, Peru, Paraguay, Ecuador and Mexico, parasites similar to L. major have already been isolated of patients who have never been outside these countries. These parasites were named Leishmania (L.) major-like. Several studies have characterized those strains using biochemical, biological and molecular techniques, however, the presence of this parasite in the New World is still unclear. In Brazil, eight of genus Leishmania species have already been characterized as causing American cutaneous leishmaniasis including L. (L.) major-like. The present study investigated the genetic heterogeneity of BH49, BH70, BH121, BH122, BH129 e BH135 L. major-like isolates in Brazil, using microsatellite typing (MLMT) and sequencing of amplified DNA fragments with three molecular targets (ITS-1, hsp70 and nagt), compared to L. major, in order to verify the occurrence of inter and intraspecific genetic diversity in these parasites. The results of this study are relevant for the establishment of public health measures for identification of Leishmania species before treatment in geographic regions where different species can be circulating. In addition, it contributes to show the complexity of Leishmania species within a continental country as Brazil with a high of parasite and vectors diversity.