Species Identification and Genotyping of Cutaneous Leishmaniasis in Clinical Samples Based on ITS1-PCR-Sequencing in Southeast Iran.

Abstract

Background: Cutaneous leishmaniasis (CL) is one of the most common parasitic diseases in many regions of Iran. It has a major role in deprived societies. We aimed to identify Leishmania species based on molecular as ITS1-rDNA-PCR internal transcribed spacer 1 (ITS1) region, microscopy, and culture techniques in diagnosing cutaneous leishmaniasis.

Methods: From April 2018 to May 2020, we conducted a cross-sectional study involving 32 patients with suspected CL lesions in Sistan and Baluchistan Province, located in southeast Iran. Samples were subjected to microscopic examination, culture, and PCR amplification targeting the internal transcribed spacer 1 (ITS1) region. DNA sequencing was performed on PCR-positive samples for species identification and phylogenetic analysis.

Results: PCR demonstrated superior sensitivity (93.75%, 30/32) compared to culture (56.25%, 18/32) and microscopic examination (53.1%, 17/32). Molecular analysis revealed that L. major was the predominant causative agent of CL in the study area, with L. tropica occurring less frequently. Sequencing and phylogenetic analysis of the ITS1 region showed high intraspecies similarity among L. tropica isolates, while L. major isolates exhibited greater genetic diversity.

Conclusion: This study shows the co-existence of L. major and L. tropica in Mirjaveh, southeast Iran, with L. major as the primary cause. While L. tropica isolates displayed high genetic similarity, L. major samples were more diverse, indicating different epidemiological patterns. These findings highlight the importance of molecular methods for accurately identifying Leishmania species and understanding CL epidemiology in the region.