Recent advances in molecular characterization of Sarcocystis species in some meat producing animals: an updated review

Sarcocystosis is a parasitic disease caused by Sarcocystis species that infect humans and animals. It is prevalent in small ruminants like sheep and goats worldwide and causing pathogenic impacts that lead to economic losses owing to carcass condemnation, abortion, and death. Recently, several molecular and phylogenetic analyses have been developed to differentiate Sarcocystis species including, the 18S rRNA, 28S rRNA, 18S rDNA, and ITS-1 region. In recent years, the mitochondrial cytochrome c oxidase subunit 1 (cox-1) was successfully used for this purpose. The DNA barcoding using the cox1 gene is a reliable tool to distinguish and identify the main Sarcocystis genotypes. Therefore, several studies confirmed that the cox1 gene is a promising DNA marker for studying the genus Sarcocystis. The current review aims to highlight the molecular methods that exist for the identification of Sarcocystis species. The results showed that the Sarcocystis species of sheep and goats were genetically close related and may be considered as sibling strains, as well as the cross-infection may happen among them. Consequently, the host specificity of several Sarcocystis species is questionable. The findings additional emphasized that experimental transmission investigations within the proposed definitive host are required to confirm the characteristics and host ranges of the Sarcocystis spp. in sheep and goats. The current review represents updated knowledge about molecular discrimination of Sarcocystis species in small ruminants by reviewing and analyzing the recent articles in this aspect.