Molecular Identification of Agents of Human Cutaneous Leishmaniasis and Canine Visceral Leishmaniasis in Different Areas of Iran Using Internal Transcribed Spacer 1 PCR-RFLP

Leishmaniasis is a major medical health problem and distributes in nearly half of 31 provinces of Iran. We aimed to identify cutaneous and visceral Leishmania spp. isolated from infected humans and domestic dogs in various regions of Iran, 2010‒2013.
DNA was extracted from 108 lesion exudate samples of suspected patients to cutaneous leishmaniasis and nine liver and spleen aspirates of infected dogs cultured in RPMI-1640 and amplified using partial sequence of ITS1 gene. The PCR amplicons were digested using HaeIII endonuclease enzyme and used in restriction fragment length polymorphism (RFLP) assay. Then, 48 amplicons representing various hosts were sequenced and compared to se­quences from GenBank databases using BLAST.
PCR-RFLP analysis showed that 60 and 48 CL patients were infected by Leishmania tropica and L. major, respectively. From nine canine visceral leishmaniasis (CVL) isolates, eight isolates were identified as L. infantum and one as L. tropica. The greatest similarity of 95.7% in ITS1 region was seen between L. infantum and L. major. Furthermore, the lowest similarity with 65.7% was seen between L. tropica and L. major. Intra-species comparison of ITS1 region in L. infantum, L. major and L. tropica isolates were showed 100%, 98.2% and 72.4 % similarities, respectively.
PCR-RFLP based on ITS1 region is an appropriate method to distinguish three Leishmania spp. of L. major, L. tropica, and L. infantum. In intra-species comparison of ITS1 region, genotypic variations showed that L. tropica isolates were more heterogeneous than L. major and L. infantum isolates.