Abstract
Sarcocystosis is a parasitic disease caused by an intracellular protozoan parasiteSarcocystisbelonging to the phylum Apicomplexa. These parasites have a requisite two-host life cycle. Recently, there are manySarcocystisspecies that identified morphologically. In the present study, diaphragmatic muscle samples from the domestic horse (Equus caballus) were examined forSarcocystisinfection. The natural infection with sarcocysts was recorded to be 62 center dot 5% for only microcysts in the infected muscles. Molecular analysis using the18S rRNAgene was conducted to swiftly and accurately identify the recovered species. Studies on the expression of the18S rRNAgene have confirmed that the present parasite isolates belong to theSarcocystisgenus. The sequence data showed significant identities (>80%) with archived gene sequences from species within the Sarcocystidae family, and a dendrogram showing the phylogenetic relationship was constructed. The most closely related species were the previously describedSarcocystis fayeriandSarcocystis bertrami. The current data showed that the present species was identified asS. fayeriand deposited in GenBank (accession number MF614956.1). This study highlights the importance of the genetic data in the exact taxonomy within sarcocystid species.