Genetic diversity of Leishmania tropica: Unexpectedly complex distribution pattern

•We analyzed a collection of clinical cutaneous leishmaniasis samples from Syrian and Turkish patients using internal transcribed spacer 1 (ITS1) sequences.•All obtained sequences belonged to Leishmania tropica.•A broad-scale analysis of genetic diversity of L. tropica throughout its geographic range showed that some genetic variants of this parasite are widespread across endemic countries and others restricted to particular regions.•Some genetic variants may be associated with alternative vectors or animal reservoirs. In this study, we characterized a collection of clinical samples obtained from Syrian and Turkish patients with cutaneous leishmaniasis using internal transcribed spacer 1 (ITS1) sequences. All obtained sequences belonged to Leishmania tropica. Combining them with those available from GenBank allowed us performing a broad-scale analysis of genetic diversity for this species. We demonstrated that L. tropica has a complex phylogeographic pattern with some haplotypes being widespread across endemic countries and others restricted to particular regions. We hypothesize that at least some of them may be associated with alternative vectors or animal reservoirs.