Porcine rotavirus B (RVB) is a pathogen that causes severe diarrhoea in suckling and weaned pigs. RVB is also a zoonotic pathogen, repeatedly transmissible from animals to humans and vice versa. Because RVB is difficult to propagate in serial cell cultures, genetic information about its RNA segments remains unknown. Non-structural protein 1 (NSP1) is thought to play an important role in modulating host immune responses so that viruses can successfully replicate. In the present study, we conducted sequence and phylogenetic analyses focusing on NSP1 using 15 porcine RVB strains collected throughout Japan. Our analysis elucidates the nucleotide sequences of NSP1 genes from 15 porcine RVB strains and shows that these genes contain 2 open reading frames encoding peptides 1 and 2. Comparison of NSP1 nucleotide and deduced amino acid sequences from porcine RVB strains demonstrates low identities with those of human and bovine RVB strains, suggesting large genetic divergence in porcine RVB. Moreover, phylogenetic analysis classifies RVB NSP1 peptides 1 and 2 into 7 genotypes according to genetic relatedness and species of origin. Notably, the NSP1 genes of porcine RVB strains can be divided into 3 genotypes. Our findings contribute to the elucidation of the evolution and ecology of RVB.
(Viral Disease and Epidemiology Research Division)
Suzuki, T. et al (2011) J. Gen. Virol. 92:2922-2929