The VP4 and VP7 of bovine rotavirus VMRI are antigenically and genetically closely related to P-type 5, G-type 6 strains

We have previously reported the isolation of a bovine rotavirus, designated VMRI, with a super-short electropherotype. We have characterized this strain further as it has shown antigenic differences with the prototype G6 strain NCDV-Lincoln. In this communication, we report the antigenic and molecular characterization and the nucleotide sequence of the VP4 and VP7 genes of this strain. Virus neutralization tests indicated 2- to 13-fold differences in the titers between NCDV-Lincoln, B641 and VMRI strains. Northern blot hybridization results indicated a degree of heterogeneity in the VP4 gene of these strains which can be detected under conditions of high stringency, The VP4 and VP7 genes of the VMRI strain were cloned and sequenced and compared with the published sequences of other bovine rotavirus strains. The VP4 gene of VMRI had a high degree of homology with that of UK and B641 strains but differed significantly from that of both NCDV-Lincoln and B223 strains. Sequence analysis of the VP7 gene of VMRI and other strains indicated a high degree of conservation and the amino acid identity between the different strains was 96%. Sequence information regarding these strains and field isolates will assist in the generation of effective vaccination strategies for control of neonatal calf diarrhea.