Multi-site DNA polymorphism analyses of Leishmania isolates define their genotypes predicting clinical epidemiology of leishmaniasis in a specific region

Leishmania isolates from 57 cases of human cutaneous (CL), human visceral ( VL), and canine visceral (CVL) leishmaniasis in Turkey were grouped by mult i-site DNA polymorphism analyses into five genotypes. The initial grouping was based on DNA heterogeneity of the faster-evolving mitochondrion (kineto plast) minicircles and the intergenic regions of two nuclear repetitive gen es. Taxonomic affiliation and phylogenetic relationships of the five genoty pes were inferred by comparing them with reference species for sequence het erogeneity in a similar to1.4 kb conserved single-copy gene, encoding N-ace tylglucosamine-1-phosphate transferase (NAGT). Alignment of the available s equences revealed no gap, but up to 7% scattered base substitutions, sugges ting that this functionally important gene is a suitable marker. Three geno types are completely identical to the NAGTs of the reference species, ident ifying them as L. infantum, L. tropica, and L. major, respectively. The rem aining two are recognized as L. major NAGT variants with one and four base substitutions, respectively. As expected, Maximum Likelihood analysis of th e NAGT sequences separates them into three clades, corresponding to the thr ee species. The majority of die isolates obtained are L. infantum and L. tr opica, which have been known to cause infantile VL and anthroponotic CL in western and southeastern Turkey, respectively. Unexpected is the finding of Leishmania major variants and their dispersal, possibly as previously unre cognized clinico-epidemiologic entities of CL and VL.