Phylogenetic insights into Leishmania species circulating among humans, vectors, and reservoir hosts in Shiraz, Southern Iran: implications for leishmaniasis control

Leishmaniasis remains a significant public health challenge in southern Iran, particularly in the Fars province, where Shiraz is a major focus of the disease. This study aimed to elucidate the phylogenetic relationships of Leishmania species isolated from humans, sand flies, and reservoir hosts in Shiraz and its suburbs. Cutaneous slit biopsies were collected from 350 suspected human cases of cutaneous leishmaniasis (CL), and samples were also obtained from rodents (Tatera indica) and sand flies (Phlebotomus papatasi). Parasites were cultured, and DNA was extracted for PCR amplification of the minicircle kinetoplast DNA (kDNA) gene. Phylogenetic analysis was performed using Neighbor-Joining and Maximum Likelihood methods. The results revealed the presence of Leishmania major, L. tropica, and L. infantum, with L. major being the predominant species. Phylogenetic trees demonstrated high genetic similarity between local isolates and those from other regions, including Iran, the UK, and Spain. This study highlights the complex transmission dynamics of Leishmania in Shiraz and underscores the need for targeted control strategies. The findings contribute to a deeper understanding of the genetic diversity and evolutionary relationships of Leishmania species in endemic regions.