Frequency and Molecular Identification of Leishmania Parasites in Smears Prepared from Skin Lesions of Patients Referred to Health Centers of Ilam Province by Digestion of the rDNA-ITS1 Gene

Ilam is a border province and a high risk zone for zoonotic cutaneous leishmaniasis (ZCL). Identification of Leishmania parasite species in clinical infections is a prerequisite for planning appropriate control measures. This study investigates the demographic characteristics of patients and molecular epidemiology of Leishmania parasites in the skin lesions of patients from Ilam Province.
A total of 106 cases of suspected cutaneous leishmaniasis were detected passively and microscopic slides prepared from their active skin lesions. We randomly selected 50 slides. A fragment of the rDNA-ITS1 gene was amplified after which the PCR products digested with HaeIII restriction enzyme. There were 18 samples sequenced and their phylogenetic relationships compared with sequences retrieved from GenBank.
Leishmania amastigotes were detected in 100 slides. The highest and lowest distribution of cases was from the Moosian and Dehloran districts, respectively. There were 68.9% males and 31.1% of cases were women. The RFLP pattern of all samples was similar to Leishmania major. Phylogenetic relationships displayed great similarity between our sequences and those of Leishmania major parasites from sandflies trapped in Ilam and South Khorasan Provinces and human hosts from Esfarayen, Mahshahr and Afghanistan plus Leishmania mexicana of Venezuelan origin classified together in the same clade.
Due to homogeneous morphology, problems associated with the cultivation of Leishmania and the two-step molecular identification process, the rDNA-ITS1-RFLP method has gained considerable attention in recent years. This method could be used as a very sensitive, simple, rapid and inexpensive method to detect Leishmania parasites in a variety of clinical and non-clinical samples.