Tissue tropism of bovine coronavirus may not be determined by viral genes

Bovine coronavirus (BCoV) causes respiratory and enteric diseases in cattle; however, the determinants of its tissue tropism remain unclear. In this study, we identified identical BCoV whole-genome sequences in tracheal and colonic samples obtained from a single adult cow that died from winter dysentery. After five passages in HRT-18 cells, virus isolation was successfully achieved only from the tracheal sample. Several amino acid substitutions were detected exclusively after isolation. These findings suggest that BCoV tissue tropism is not determined solely by viral genome sequences. It is important to analyze viral genomes directly from clinical samples prior to virus isolation.