Prevalence and genetic characterization of diarrhea viruses among cattle in Guangdong, China

Background Bovine coronavirus (BCoV), bovine norovirus (BNoV), and bovine rotavirus C (BRVC) are common diarrheal viruses in cattle and pose significant threats to herds and humans. In this study, we collected 194 fresh fecal samples from September 2022 to January 2024 in Guangdong Province, China. We present the genetic characteristics of two new BCoV (GD-GZ-01 and GD-GZ-02), a new BNoV (BYN7) and 22 BRV (BRVC, BRVB, and BRVH) strains identified. Genetic analysis was conducted via MEGA-X and the maximum likelihood method. The reference strains’ related genes were retrieved from GenBank for comparison and analysis via MegAlign. Results The detection rates for BCoV, BNoV, and BRVC were 8.76% (17/194), 15.98% (31/194), and 5.67% (11/194), respectively. We reported prevalence data of BRVC for the first time in cattle in China. The phylogenetic tree showed that BCoV strains GD-GZ-01 and GD-GZ-02 were branched Chinese Zhejiang or Xinjiang strains from the Betacoronavirus group; BNoV strain BYN7 contains new gene sequences, the VP1 and VP2 genes, from the GIII.2 subgroup and may have originated from Chinese Sichuan yaks strain. Additionally, BCoV has a close genetic relationship with the human OC43 strain, suggesting potential risks for cross-species transmission. The 22 BRV rotavirus strains (10 BRVB strains, 11 BRVC strains, and one BRVH strain), identified by Metaviromesequencing, formed distinct phylogenetic clusters respectively. Conclusions BCoV, BNoV, and BRVC exhibited relatively low prevalence levels in Guangdong, China. Notably, the prevalence of BRVC was reported for the first time in China. Our study confirmed that there were disparities in the infection rate regarding sampling site type. Genetic characterization suggested that the identified BCoV strains (GD-GZ-01 and GD-GZ-02) may have originated from Zhejiang or Xinjiang, BNoV (BYN7) could be a new mutant from a Sichuan yak strain, and 22 BRV strains are new mutants in new clusters. It suggested potential risks of cross-regional and cross-species transmission of these viruses.