molecular identification of macroscopic and microscopic cysts of sarcocystis in sheep in north khorasan province, iran

sarcocystis is an obligatory intracellular protozoan parasite which can infect humans and animals. sheep are intermediate hosts of four sarcocystis species: sarcocystis tenella, sarcocystis gigantea, sarcocystis arieticanis, and sarcocystis medusiformision. the purpose of the study was to determine the molecular identification of the macroscopic and microscopic cysts of sarcocystis in sheep. in this investigation, we assessed the macroscopic and microscopic cysts of sarcocystis in sheep carcasses. the digestion method was used for observing of bradyzoite in heart, liver, diaphragm and muscle samples. pcr analysis was conducted on macroscopic and microscopic cysts and also all other samples. sequencing was done for ten pcr products. genotypes were identified by blast search and homology analysis. macrocyst was seen in two muscle tissues. digested method and pcr analysis were positive in all samples (heart, liver, diaphragm muscle). genotyping of ten tissues samples proved that the genotype of macroscopic and microscopic cysts belonged to sarcocystis gigantea and sarcocystis tenella, respectively. microscopic cysts are more prevalent than macroscopic cysts and they can cause enormous economic losses.