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 medusiformis The purpose of this study was to perform a molecular identification of the macroscopic and microscopic cysts of Sarcocystis in sheep. In this investigation, the macroscopic and microscopic cysts of Sarcocystis were assessed in slaughtered sheep. The digestion method was used for bradyzoites observation in heart, liver, diaphragm and muscle samples. PCR analysis was conducted on macroscopic and microscopic cysts and also all other samples. Sequencing was performed for ten PCR products. Genotypes were identified by BLAST search and homology analysis. Macrocysts were seen in two muscle tissues. Digestion method and PCR analysis revealed positive results in all samples taken from heart, liver, diaphragm, and muscle. Genotyping of ten tissue samples proved that the genotype of macroscopic belonged to Sarcocystis gigantea and microscopic cysts to Sarcocystis tenella. Microscopic cysts are more prevalent than macroscopic cysts and they can cause enormous economic losses.
Keywords: Sarcocystis gigantea; Sarcocystis tenella; molecular analysis.