Identification of Leishmania species using N-acetylglucosamine-1-phosphate transferase gene in a zoonotic cutaneous leishmaniasis focus of Iran

摘要

Background & objectives: Ilam province is one of the oldest known endemic foci of zoonotic cutaneous leishmani- asis (CL) in Iran; and the recent studies have shown an increasing trend in the number of cases from the region. This study was aimed to investigate the parasite species and genetic diversity of isolates obtained from CL patients based on the N-acetylglucosamine-1-phosphate transferase (nagt) gene. Methods: Exudate materials were collected from the swollen margin of the skin lesions of the patients suspected with CL who were referred to health centers laboratory of Mehran, Dehloran, Ilam and Malekshahi cities in the Ilam province. Demographic data were collected through a questionnaire. Smears were stained and examined microscopically. In total, 62 parasitologically positive samples were subjected to PCR-RFLP of nagt gene for identification of Leishmania species, in addition to genetic diversity investigation. Results: Nearly, half of the positive cases were referred from Mehran followed by Dehloran City (40.4%). These included people from different age groups (1 to 73 yr), with majority being male (66.1%). The common site of lesions was hand (48.4%). Half of the patients had multiple lesions; most of them were wet ulcerative type. A 1450-60 bp band of the nagt gene was amplified from all the samples. Digestion patterns of acetyl-coenzyme A carboxylase 1 (ACC1) enzyme were similar to what expected for Leishmania major. No difference was observed at the nucleotide acid level or resulting amino acid in nine sequenced samples on the basis of phylogenetic analyses. However, intra- species differences (0.0015) were observed amongst the L. major isolates of present study and the other parts of Iran. Interpretation & conclusion: The findings of this study demonstrated that the main causative agent of CL in Ilam Province is L. major, and there is no considerable heterogeneity among the L. major isolates. Moreover, nagt gene proved to be an efficient marker for differentiating Leishmania species. Further studies with more samples need to be carried out to achieve a more comprehensive result on the genetic variation of L. major isolates.