Journal Name:
Acta Tropica
Volume:
98
Issue:
1
Pages From:
52
To:
58
Date:
Thursday, March 2, 2006
Keywords:
Leishmania major, Genetic analysis, ITS1-RFLP; PCR-SSCP, Internal transcribed spacer
Abstract:
Protozoan parasites of Leishmania major are the causative agents of cutaneous leishmaniasis in different parts of Iran.We applied
PCR-based methods to analyze L. major parasites isolated from patients with active lesions from different geographic areas in Iran in
order to understandDNApolymorphisms within L. major species. Twenty-four isolates were identified as L. major by RFLP analysis
of the ribosomal internal transcribed spacer 1 (ITS1) amplicons. These isolates were further studied by single-strand conformation
polymorphism (SSCP) analysis and sequencing of ITS1 and ITS2. Data obtained from SSCP analysis of the ITS1 and ITS2 loci
revealed three and four different patterns among all studied samples, respectively. Sequencing of ITS1 and ITS2 confirmed the
results of SSCP analysis and showed the potential of the PCR-SSCP method for assessing genetic heterogeneity within L. major.
Different patterns in ITS1 were due to substitution of one nucleotide, whereas in ITS2 the changes were defined by variation in
the number of repeats in two polymorphic microsatellites. In total five genotypic groups LmA, LmB, LmC, LmD and LmE were
identified among L. major isolates. The most frequent genotype, LmA, was detected in isolates collected from different endemic
areas of cutaneous leishmaniasis in Iran. Genotypes LmC, LmD and LmE were found only in the new focus of CL in Damghan
(Semnan province) and LmB was identified exclusively among isolates of Kashan focus (Isfahan province). The distribution of
genetic polymorphisms suggests the existence of distinct endemic regions of L. major in Iran.
