IDENTIFICATION OF GROUP-B ROTAVIRUSES WITH SHORT GENOME ELECTROPHEROTYPES FROM ADULT COWS WITH DIARRHEA

Two field strains (BB-RVLV and KD) of group B rotaviruses from adult d airy cows with diarrhea displayed short genome electropherotypes. Gnot obiotic calves inoculated with fecal filtrates of each group B rotavir us developed diarrhea, and only group B rotaviruses or antigens were d etected in the feces by immunoelectron microscopy and in intestinal ep ithelial cells by immunofluorescent staining, respectively. The feces or intestinal contents of the cows and inoculated calves were negative for group A and C rotaviruses by enzyme-linked immunosorbent assay, i mmunoelectron microscopy, or cell culture immunofluorescence assays. C omparison of the genome electropherotypes of the calf-passaged BB-RVLV and KD strains with the original samples and reference bovine group A , B, and C rotaviruses revealed conservation of their short-genome ele ctropherotypes and double-stranded RNA migration patterns characterist ic of group B rotaviruses. To our knowledge, our previews study (L. J. Saif, K. V. Brock, D. R. Redman, and E. M. Kohler, Vet. Rec. 128:447- 449, 1991) and this report are the first description of bovine group B rotaviruses (in a mixed infection with bovine coronavirus or singly i n fecal contents) in adult cows with diarrhea and this is the first re port of short-genome electropherotypes among group B rotaviruses.