Molecular determination of abundance of infection with Sarcocystis species in slaughtered sheep of Urmia, Iran

Sarcocystis is one of the most prevalent parasites of domestic ruminants worldwide. This study was aimed to determine prevalence of Sarcocystis infection and molecular discrimination of Sarcocystis gigantea and Sarcocystis medusiformis infecting domestic sheep. Tissue samples from ۶۳۸ sheep slaughtered at Urmia abattoir were randomly collected from February ۲۰۱۱ to January ۲۰۱۲. Genomic DNA extraction and polymerase chain reaction (PCR) was performed to amplify a ۹۶۴ bp fragment of nuclear ۱۸S rRNA gene. The PCR products were subjected to digestion with endonuclease MboII and/or MvaI for discriminating S. medusiformis and S. gigantea. Results indicated that the overall prevalence of Sarcocystis unspecified species was ۳۶.۸۳% (۲۳۵/۶۳۸) in which male (۷.۶۳%, ۳۸/۴۹۸) and female (۳۵.۰۰%, ۴۹/۱۴۰) sheep over ۴ years-old had the highest prevalence. There was no significant difference between prevalence of macrosarcocysts and sex. Two macrosarcocysts forms were found as fat (۲۷.۹۰%, ۱۷۸/۶۳۸) and thin (۸.۹۳%, ۵۷/۶۳۸) in striated muscles. There was significant difference between frequency of macrosarcocysts and body distribution. Mixed infection with both fat and thin macrosarcocysts was also found in ۱۱.۱۳% (۷۱/۶۳۸) of infected sheep. There was no significant difference regarding the prevalence of mixed infection in both age classes. The PCR-RFLP patterns showed that fat sarcocysts were S. gigantea (۲۹.۳۱%, ۱۸۷/۶۳۸) and thin sarcocysts were S. medusiformis (۷.۵۲%, ۴۸/۶۳۸). It was concluded that ovine Sarcocystis infection was prevalent in Urmia and a combination of conventional methods and molecular study for sheep sarcocysts could be informative.

Keywords:

Molecular analysis , Sarcocystis , Sheep , Urmia