Genetic Identification of Echinococcus granulosus Isolates in Hamadan, Western Iran

Cystic echinococcosis is a zoonotic infection and considered as a major economic and public health concern worldwide. This research was conducted to determine genotypic characteristics of livestock and human hydatid cyst isolates from Hamadan area, western Iran. Sampling was conducted in Hamadan industrial slaughterhouse and Beast Hospital of Hamadan City, western Iran, from 2015 to 2016. Overall, 74 livestock isolates including 69 sheep, 3 cattle and 2 goats and 9 human hydatid cysts were genotyped by PCR amplification of the rDNA ITS1 region and followed restriction fragment length polymorphism (RFLP) analysis with four restriction endonuclease enzymes, RsaI, HpaII, AluI, and TaqΙ, and sequencing. The PCR amplicon size of each isolate was approximately 1 kb which was the same with that of sheep strain. According to the RFLP patterns, the isolates belonged to a single species, E. granulosus sensu stricto (G1–G3 complex). Furthermore, sequencing of representative amplicons confirmed that the RFLP-genotyped isolates corresponded to E. granulosus sensu stricto. E. granulosus sensu stricto is the prevailing species of E. granulosus sensu lato in the region and pointed out the importance of sheep/dog cycle in human transmission.