identification and genetic variation of fasciola species from tabriz, north- western iran

background:  fascioliasis is considered as the most important helminthic infection of cattle and sheep. traditional approaches using morphological and biologic characters cannot cause a cer­tainty in the accurate and precise identification and intra-specific differences of fasciola spp. in this study, we identified fasciola species using its-1 marker and described genetic variation of each species of the parasite in isolates from tabriz slaughterhouse in west azerbaijan province, north- western iran. methods: overall, 100 samples (50 from sheep and 50 from cattle) morphologically detected as fasciola worms were studied for identification of fasciola species by pcr-rflp method and intra-species variation of the parasite using rapd-pcr technique. results: a region of approximately 460bp in all samples was successfully amplified. there were no identifiable variations among the size of pcr products. two and three fragments in samples correspond to f. hepatica and f. gigantica was seen, respectively, through pcr-rflp method. no difference was seen in digestion pattern according to host (sheep or cattle). different types of each species of the parasite was observed using rapd-pcr technique. conclusion: we could have an estimate of frequency of f. hepatica and f. gigantic and different genotypes of the parasite in isolates from one locality in north- western of iran. by extension of such studies in future to other animal hosts (buffalo and goat) and including more regions to sam­pling, the reliability of the results and their  application for control programs in zoonotic diseases will be increased.