Identification of the agent causing visceral leishmaniasis in Uzbeki and Tajiki foci by analysing parasite DNA extracted from patients' Giemsa-stained tissue preparations

Abstract

Our present study is the first attempt to characterize Leishmania parasites from foci in Uzbekistan and Tajikistan endemic for visceral leishmaniasis (VL). PCR-sequencing of the ribosomal internal transcribed spacer 1 and multilocus microsatellite typing (MLMT) were applied to DNA extracted from preparations of Giemsa-stained bone marrow aspirates from 13 cases of VL. L. infantum was shown to cause VL currently occurring in this area. MLMT applying 14 microsatellite markers, previously shown to be polymorphic for strains of the L. donovani complex, revealed that microsatellite profiles of parasites causing human VL in the Namangan and Jizzakh regions in Uzbekistan, and Penjikent region in Tajikistan, basically coincide with those of strains of L. infantum MON-1. Furthermore, these parasites were assigned to a distinct cluster genetically clearly separated from the populations of L. infantum MON-1 from Europe, the Middle East and North Africa. The existence of a genetically homogeneous but distinct group of L. infantum MON-1 indicates that the parasites circulating in the Uzbeki and Tajiki foci studied have been restricted there for a long time rather than having been recently introduced from elsewhere by human or animal reservoir migration.