Occurrence and Molecular Characterization of spp. in Dairy Cattle and Dairy Buffalo in Yunnan Province, Southwest China.

spp. are important foodborne and waterborne pathogens in humans and animals, causing diarrheal diseases. Cattle are one of the reservoirs of infection in humans. However, data on the occurrence of spp. in cattle in Yunnan Province remains limited. A total of 700 fecal samples were collected from Holstein cows ( = 442) and dairy buffaloes ( = 258) in six counties of Yunnan Province. The occurrence and genotypes of spp. were analyzed using nested PCR and DNA sequencing. Furthermore, the isolates were further analyzed using multilocus sequence typing (MLST) at four gene loci (MS1, MS2, MS3, and MS16), and the isolate was subtyped by 60-kDa glycoprotein (60) loci. The occurrence of spp. in Holstein cows and dairy buffaloes was 14.7% (65/442) and 1.1% (3/258), respectively. Of these positive samples, 56 Holstein cow samples represented , four Holstein cow samples represented , three Holstein cow samples represented , and one represented . Meanwhile, only three dairy buffalo samples represented . MLST analysis of subtypes of detected four subtypes, including A5A4A2A1 ( = 7), A4A4A4A1 ( = 7), A1A4A4A1 ( = 2), and A4A4A2A1 ( = 1). One isolate was identified as the IIdA18G1 subtype. These results revealed the high occurrence and high genetic diversity of spp. in Holstein cows in Yunnan Province, enriching the knowledge of the population genetic structure of spp. in Yunnan Province.