Occurrence and Molecular Characterization of spp. in Beef Cattle in Yunnan Province, China.

spp. are protozoan pathogens that are widespread within mammals. In recent years, extensive molecular epidemiology studies on in dairy cattle have been conducted in Yunnan and worldwide. However, the infection status of these pathogens in beef cattle in Yunnan remains unclear. To examined the occurrence of spp. in beef cattle in Yunnan Province, China, we collected 735 fecal samples from six breeds of beef cattle in five regions of Yunnan. Nested PCR and DNA sequencing revealed the infection, species, and genotypes of spp. in these animals. The occurrence of spp. in Simmental cattle, Brahman cattle, Aberdeen Angus cattle, Yunnan Yellow cattle, Dulong cattle, and Hereford cattle was 32.9% (137/416), 3.8% (4/106), 24.4% (20/82), 3.8% (3/79), 3.2% (1/31), and 0% (0/21), respectively, with an overall rate of 22.4% (165/735). Regarding the regions, the occurrence of spp. in Boshan City, Kunming City, Lincang City, Dehong City and Xishuangbanna City was 41.8%, 28.6%, 19.4%, 6.7%, and 3.8%, respectively. In terms of age, the infection rates of spp. in pre-weaned, post-weaned, juvenile, and adult cattle were 62.1%, 52.6%, 42.7%, and 7.7%, respectively. According to sex, male cattle were more susceptible to infection (28.0%) than females (15.7%). Four species were identified in beef cattle: ( = 146), ( = 11), ( = 7), and ( = 1). Multilocus sequence typing analysis at the MS1, MS2, MS3, and MS16 gene loci revealed four subtype families of (A4A4A4A1, A5A4A4A1, A4A4A2A1, A1A4A4A1). Additionally, sequencing analysis of the 60-kDa glycoprotein gene identified three subtype families of (XXVIc, XXVId, XXVIe) and one subtype family of (XXIb). These findings document the occurrence of spp. in beef cattle in Yunnan Province for the first time, providing reference data on the distribution, infection rate, species diversity, and genetic structure of these pathogens in China. To effectively reduce the prevalence of spp. in beef cattle in Yunnan, the implementation of proper sanitation management, rigorous rodent control, and farmer education programs is crucial. These integrated measures are critical for maintaining herd health, reducing economic losses, and ensuring meat safety across the province.