Molecular epidemiology of cutaneous leishmaniasis and heterogeneity of Leishmania major strains in Iran.

OBJECTIVE

To determine the geographical distribution of Leishmania species causing cutaneous leishmaniasis (CL) and to study the genetic heterogeneity of Leishmania major isolates from different endemic areas of Iran.

METHODS

A total of 341 isolates from lesions of patients living in 11 provinces of Iran were grown in culture medium and inoculated to BALB/c mice to detect possible visceralisation. The species were identified by isoenzyme analysis using a battery of six enzymes and kinetoplast (k) DNA-PCR technique. Genetic variation among L. major isolates was analysed by random amplified polymorphic DNA (RAPD) technique.

RESULTS

Of the total 341 isolates, 283 isolates were L. major and 58 isolates were Leishmania tropica. In rural areas, the causative agent of CL was mainly L. major (95%L. major vs. 5%L. tropica), in urban areas it was L. tropica (65%L. tropica vs. 35%L. major). All isolates of L. major and 8.6% of L. tropica isolates showed visceralisation in BALB/c mice. There is considerable genetic diversity between L. major strains from different endemic areas and even between some isolates of the same endemic area.

CONCLUSION

Leishmania major is the most frequent species in the endemic areas of CL in eleven provinces of Iran, and genetic diversity is a common feature of L. major in the country.