Detection and Genetic Diversity of Bovine Kobuvirus in Diarrheic Calves in Türkiye: Genomic Characterization and Comparative B-Cell Epitope Analysis

Kobuviruses infect a wide range of hosts and exhibit high genetic diversity, highlighting the need for further studies to better understand their evolution and impact on animal health. In the present study, bovine kobuvirus (BKoV) was detected in 40 of 154 fecal samples from calves using the primers targeting the 3D gene region, corresponding to an overall positivity rate of 25.97%. All positive samples were obtained from diarrheic calves younger 30 days of age, (40/133; 30.08%), consistent with previous studies. To enable more reliable genotyping, the complete VP1 gene sequences of seven BKoV strains were obtained, and the phylogenetic analyses showed that all VP1 sequences of this study clustered within Aichivirus B1. Additionally, immunoinformatics analysis of the VP1 protein identified conserved linear and discontinuous B-cell epitopes that may represent potential targets for cross-reactive diagnostic assays or future vaccine studies. The complete coding sequence of one strain, K056/2008/TUR, was also generated, and molecular analysis of this strain provided further evidence of ongoing viral evolution and genetic diversity in Türkiye. Overall, these findings provide new insights into the prevalence, genetic diversity, and predicted immunogenic features of BKoVs in calves in Türkiye, supporting further studies on its pathogenesis, diagnostics, and antigenic properties.