ABSTRACT
Hydatid cyst in the larval stage of the tapeworm Echinococcus granulosus, a member of cestodes. This parasite causes echinococcusis in human and some other mammalians. To date, the different strains of the parasite have been reported across the world and this variation may affect the epidemiology and pathogenicity of the Hydatid cyst. Therefore, using polymerase chain reaction based restriction fragment length polymorphism [PCR-RFLP] this study was aimed to conduct the molecular characterization of the protoscolex stage of the parasite in Chaharmahal va Bakhtiary province, Iran. In this study, 30 samples of sheep-hydatid cysts were collected from slaughterhouses across the province. Subsequently, using phenol-chloromphorm method, DNA of the samples was extracted, and then the ribosomal DNA-internal transcribed spacer1 [rDNA-ITS1] fragment of each isolate was amplified using primer BD1 [forward] and 4S [reverse]. The primers were either genus or species specific. Finally, the PCR products were digested using restriction enzymes Alul, RSal, Hpall, and Taql and subjected to electrophoresis and staining. The size of PCR product in this research was 1000 base pair [bp]. Using Alul enzyme, two fragments of 800bp and 200bp were created. Rsal digestion also revealed two fragments of 345bp and 655bp. Digestion with HpaII enzyme, created two fragments of 700bp and 300bp. Finally, when Tapl enzyme was used no digestion occurred. The final results of this investigation showed that the sheep-hydatid cyst strain in Chaharmahal va Bakhtiary province of Iran is G[1], which is the same as sheep strains all over the world