Molecular characterization of the VP1, VP2, VP4, VP6, NSP1 and NSP2 genes of bovine group B rotaviruses: identification of a novel VP4 genotype.

Studies on bovine group B rotaviruses (GBRs) are limited. To date, only the VP6 gene of a single bovine GBR strain and the VP7 and NSP5 genes of a few bovine GBR strains have been sequenced and analyzed. In the present study, using a single-primer amplification method, we have determined the full-length nucleotide sequences of the VP1, VP2, VP4, VP6, NSP1 and NSP2 genes of three bovine GBR strains from eastern India. In all six of these genes, the bovine GBR strains shared high genetic relatedness among themselves but exhibited high genetic diversity with cognate genes of human, murine and ovine GBRs. Interestingly, as with group A rotaviruses, the bovine GBR VP1, VP2, VP6 and NSP2 genes appeared to be more conserved than the VP4 and NSP1 genes among strains of different species. The present study provides important insights into the genetic makeup and diversity of bovine GBRs, and also identifies a novel GBR VP4 genotype.