ABSTRACT
Sarcocystis species are intracellular protozoan which mostly complete their life cycle in two hosts. The parasite has a significant economic, medical and veterinary impact in many regions of the world and considered as a significant health problem in Iran. However, most of infections are asymptomatic and mortality is extremely rare. The present study aimed to determine the molecular phylogeny of the Sarcocystis species isolated from sheep slaughtered in southwest Iran, using mitochondrial DNA sequences of 18 S rRNA gene. The DNA was extracted from sheep muscular tissue (n = 60), and partial sequence of 18 S rDNA was amplified and sequenced. Phylogenetic analysis revealed two monophyletic clades representing S. moulei (n = 3) and Sarcocystis spp. (n = 3). BI posterior probability and MP bootstrap values strongly supported the monophyly of these clades. In conclusion, phylogenetic analysis of Sarcocystis species using 18 S rRNA gene could be helpful in identifying the new species of the Sarcocystis.
