Molecular characteristics of Sarcocystis spp. in sheep from slaughterhouse in Xinjiang, China.

Sarcocystis is an important zoonotic protozoan parasites. This study collected 354 tissue samples (22 skeletal muscle samples, 74 diaphragm samples, 171 heart samples, and 87 esophagus samples) from 354 sheep across seven slaughterhouses in seven cities of Xinjiang. Screening for Sarcocystis spp. was performed using PCR targeting the 18S rRNA gene, with confirmation PCR targeting the COX 1 gene. The infection rate was determined to be 30.2% (107/354). All seven cities tested positive for Sarcocystis, with the highest infection rate in Tacheng (95.5%, 21/22) and the lowest infection rate in Kuqa (9.2%, 9/98). The infection rates by tissue were as follows: 95.5% (21/22) in skeletal muscles, 40.5% (30/74) in diaphragm, 24.0% (41/171) in heart, and 17.2% (15/87) in esophageal, respectively. Two Sarcocystis species were identified from the 107 positive samples: S. tenella (n = 106) and S. arieticanis (n = 1). Five genotypes of S. tenella and one genotype of S. arieticanis were identified, all of which clustered closely with previously discovered isolates. These results enhance our understanding of the epidemiological status of Sarcocystis in sheep in Xinjiang.