A one health study on phylogenetics and risk of pathogenic intestinal parasites at a ranch in Inner Mongolia

<i>Cryptosporidium</i>, <i>Giardia duodenalis</i>, and <i>Enterocytozoon bieneusi</i> are widespread zoonotic pathogens causing gastrointestinal diseases in humans and various animal species. Inner Mongolia, a major beef production region in China, there is a notable absence of comprehensive research on intestinal parasitism. Thus, timely and comprehensive diagnosis is essential to mitigate disease spread and minimize economic losses in the livestock industry. In this study, we collected fecal samples from cattle and humans, as well as soil and water samples, and all samples were tested for pathogenic intestinal protozoa at the Simmental cattle ranch in Wengniute, Chifeng City, Inner Mongolia. Among the 393 samples tested, 76/371 (20.5 %) cattle, 6/11 (54.5 %) ranch workers, 1/7 (14.3 %) water, and 2/4 (50 %) soil samples were positive. Factors affecting the infection rate of intestinal protozoa were examined. Results showed that the infection rate was higher in June than in January, higher in calves than in adults, and higher in diarrheal calves than in healthy calves. Additionally, the infection rate of intestinal protozoa was higher in pathogen-contaminated water source sheds than in uncontaminated sheds. Genetic and evolutionary analyses revealed that the prevalent <i>E. bieneusi</i> subtypes are predominantly J, I, and BEB4, while the <i>G. duodenalis</i> subtypes are assemblages B and E. The <i>Cryptosporidium</i> species identified were <i>C. bovis</i>, <i>C. andersoni</i>, <i>C. parvum</i>, <i>C. ryanae</i>, and <i>C. suis</i>, with <i>C. parvum</i> being a notable zoonotic pathogen. The pathogen sequences from humans, cattle, water, and soil showed 99-100 % similarity, suggesting possible transmission or contamination between animals and the environment. This study contributes to the One Health approach by addressing the gap in research on intestinal protozoa in Inner Mongolia. It provides important data for other ranches in the region to understand the prevalence of such pathogens and develop effective control measures. Using the concept of One Health to analyze the spatiotemporal distribution of intestinal protozoa in pastures is of great significance for maintaining public health.