Prevalence and Genetic Characterization of Blastocystis in Sheep and Pigs in Shanxi Province, North China: From a Public Health Perspective

SIMPLE SUMMARY: Blastocystis is one of the most prevalent parasites, which can infect humans and many animal species worldwide, and the infection can result in public health problems and economic losses. Sheep and pigs are economically important animals in Shanxi province, north China; however, it is yet to be determined whether they are infected with Blastocystis. Thus, the present investigation was conducted to reveal the prevalence of Blastocystis in sheep and pigs in three representative counties in Shanxi province by examining 492 sheep feces and 362 pig feces using a molecular approach. The overall prevalence of Blastocystis in sheep and pigs were 16.26% and 14.09%, respectively. Five subtypes were found in sheep and pigs via DNA sequence analysis, of which ST5 was the dominant subtype in the three study counties. This study is the first to report the prevalence and subtypes of Blastocystis in sheep and pigs in Shanxi province. The findings not only extend the geographical distribution of Blastocystis but also provide baseline data for the prevention and control of Blastocystis infection in humans and animals in Shanxi province. ABSTRACT: Blastocystis is a common zoonotic intestinal protozoan and causes a series of gastrointestinal symptoms in humans and animals via the fecal–oral route, causing economic losses and posing public health problems. At present, the prevalence and genetic structure of Blastocystis in sheep and pigs in Shanxi province remains unknown. Thus, the present study collected 492 sheep fecal samples and 362 pig fecal samples from three representative counties in northern, central and southern Shanxi province for the detection of Blastocystis based on its SSU rRNA gene. The results showed that the overall prevalence of Blastocystis in the examined sheep and pigs were 16.26% and 14.09%, respectively. Sequences analyses showed that four known subtypes (ST5, ST10, ST14 and ST30) in sheep and two subtypes (ST1 and ST5) in pigs were detected in this study, with ST5 being the predominate subtype among the study areas. Phylogenetic analysis showed that the same subtypes were clustered into the same branch. This study reveals that sheep and pigs in Shanxi province are hosts for multiple Blastocystis subtypes, including the zoonotic subtypes (ST1 and ST5), posing a risk to public health. Baseline epidemiological data are provided that help in improving our understanding of the role of zoonotic subtypes in Blastocystis transmission.