Comparative molecular epidemiology of Leishmania major and Leishmania tropica by PCR-RFLP technique in hyper endemic cities of Isfahan and Bam, Iran.

BACKGROUND

Leishmania is an obligate intracellular protozoa, and the sandfly, as a vector, transmits infectious forms of the parasite to the vertebrate host. The etiologic agents of cutaneous leishmaniasis (CL), Leishmania major and Leishmania tropica, are the most prevalent factor in Iran, especially in the Isfahan and Bam regions. Because of the importance of CL in endemic regions and the interaction of species diversity factors in developing control strategies, several isolated Leishmania species from 2 hyperendemic regions of Iran, Isfahan and Bam cities, were examined in this study by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

MATERIAL/

METHODS

In this study, 340 samples were taken from clinically suspected CL patients to prepare slides for direct microscopy and cultures for promastigotes by PCR-RFLP. The internal transcribed spacer 1 (ITS1) region of genomic DNA was extracted and amplified with LITSr and L5.8s primers. Amplification by PCR-RFLP was performed to determine 4 kinds of genotype pattern of the species in the 2 main cities of Isfahan and Bam. Some of the product samples were sequenced and analyzed.

RESULTS

Two genotypic groups were detected from L. major isolates, LmA and LmB; also L. tropica showed 2 patterns, LtA and LtB, in comparison with standard species. The most prevalent genotypes related to isolates of Isfahan were LmA and of Bam were LtA. These 2 genotypes were recorded as major etiologic factors of CL in these 2 regions.

CONCLUSIONS

Leishmania major and L. tropica, the causative agents of zoonotic CL and anthroponotic CL, respectively, in Isfahan and Bam, are genetically highly polymorphic species, and a correlation may exist between genetic heterogeneous and clinical manifestation and geographic regions of the disease in humans.