Intraspecific Variation in Leishmania major Isolated from Different Forms of Zoonotic Cutaneous Leishmaniasis

Background: Zoonotic cutaneous leishmaniasis (ZCL) is a polymorphic disease which may show various clinical manifestations. Although genetic variability of the parasite is suggested to be one of the factors influencing clinical manifestations in leishmaniasis, no data exist regarding genetic polymorphism of Leishmania major. Therefore, determination of genetic variation within the species of L. major isolated from different cases of ZCL in Isfahan, Iran and its relation to clinical manifestation of the disease is investigated. Methods: The internal transcribed spacers (ITS) in the ribosomal operon of 9 isolates of L. major from three clinically different forms of ZCL were amplified by polymerase chain reaction (PCR), followed by the digestion of the PCR product with two restriction enzymes. The profiles were visualized in agarose gel under UV light. Results: The PCR product obtained for all isolates was about 1060 bp in size. Restriction analysis of ITS with both enzymes showed identical fragment patterns in samples isolated from clinically similar forms of ZCL, but highly diverse fragment patterns in those isolated from clinically different forms. Conclusion: L. major causing ZCL in Isfahan is genetically a highly polymorphic species and a correlation may exist between genetic heterogeneity of the parasite and the clinical manifestation of the disease in human.