molecular diagnosis of sarcocystis hominis and sarcocystis cruzi in slaughtered cattle in tabriz, iran using pcr- rflp with new digestion patterns

Sarcocystis species are intracellular protozoan parasites that cause cysts in the muscles of animals throughout the world. so far, more than 200 sarcocystis species with different life cycles and pathogenicity have been identified in different hosts, and some of these species have zoonotic importance. seven species in cattle are known to form macroscopic and microscopic cysts. of which, s. hominis and s. heydorni, are zoonotic species and s. cruzi is the most pathogenic species in cattle. this study aimed to identify the important species of sarcocystis in thirty cows slaughtered in tabriz slaughterhouse by sampling the heart, diaphragm, intercostal and triceps muscles. although no macroscopic cysts were found, prevalence of microscopic cysts were 86.6%. the results showed 926 bp and 937 bp fragments for sarcocystis hominis and sarcocystis cruzi, respectively. the bfai endonuclease was used to digest the pcr products. according to the pcr-rflp results, the rate of single infection with s. hominis and s. cruzi was 16.7% and 26.7%, respectively, and co-infection was 43.2 %. s. cruzi was showed ˷ 400bp, 300 bp, and ˷ 237 bp fragments and s. hominis was showed one ˷600bp with two overlapped ˷163 bp (2x).  in the present study, new digestion patterns were observed ‎compared to previously reported in iran with the same restriction enzyme. these results suggest the presence of heterozygosity in s.cruzi and s.hominis in different regions of iran.