National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2002

02. Development and application of an enzyme-linked immunosorbent assay for group B rotavirus antibody detection using recombinant VP6 protein


The major inner capsid protein VP6 gene of the bovine group B rotavirus (GBR) Nemuro strain was 1269 nucleotides (nt) in length and contained one ORF encoding 391 amino acids (aa).  The sequence identities of the Nemuro VP6 gene to the published human and rodent GBR cognate genes were 58-60% in nt and 70-72% in aa, which were notably less than those between human and rodent viruses.  When the Nemuro VP6 gene was cloned into a baculovirus, the expressed protein in Sf9 cells was consistent in size with that deduced from the gene sequence (43 kDa) and reacted with hyperimmune antiserum to a bovine GBR on a Western blot assay.  An enzyme-linked imunosorbent assay (ELISA) for detecting GBR antibodies was developed using this recombinant VP6 as antigens.  All 13 paired sera from adult cows with GBR diarrhea in the field showed antibody responses in the ELISA.  In serological surveys of GBR infection using the ELISA, a total of 58% of cattle sera were positive for GBR antibodies, with antibody prevalence higher in adult cattle than in young cattle.  In pigs, a high prevalence of GBR antibodies (97%) was detected in sera from sows.  These results suggest that GBR infection is common in cattle and pigs, notwithstanding the scarcity of reports of GBR detection in these species to date. (Environmental Hygiene Section, Department of Epidemiology TEL +81-176-62-5115)