Leishmania chagasi/infantum: further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America.

In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran CL and VL strains using Mediterranean L. infantum strains as a reference. Macrophage infectivity and serum sensitivity, properties thought to be associated with virulence, were similar between CL and VL strains from both regions. Attention focused on the genome organisation of genes for two candidate virulence factors: Leishmania mitogen activated protein kinase (LMPK) and cysteine proteinase b (Cpb). Interestingly, the Mediterranean strains exhibited restriction enzyme polymorphisms associated with tropism for both LMPK and Cpb genes whereas no differences were observed for the Honduran strains. We also report relative genetic homogeneity of the Honduran strains as compared to the Mediterranean strains and discuss it in terms of the probable origin for the Central American L. chagasi/infantum.