Molecular characterization of VP1-3 and NSP1-3 genes of porcine group A rotavirus G12 strain RU172: Evidence for porcine origin of human G12 strains

Abstract

Group A rotavirus is an important cause of infantile diarrhea in humans, and classified into 23 G and 31 P genotypes. Among them, G12 has been regarded as an important emerging genotype of human strains, worldwide. On the other hand, the only G12 strain reported from animals was a G12P[7] strain, RU172, detected in a diarrheic piglet in Eastern India. The VP4, VP6, NSP4 and NSP5 genes of porcine G12 strain RU172 exhibited genetic relatedness to human Wa-like G12 strains. Although the origin of human G12 genotype remains obscure, some recent studies on human G12 rotaviruses suggested that the G12 genotype might be of porcine origin. To determine the true origin of G12 rotaviruses and decipher the exact genetic relatedness between human and porcine G12 strains, we characterized genetically the remaining six genes (VP1-3 and NSP1-3) of porcine G12 strain RU172.The VP1-3 and NSP1-3 gene sequences of porcine G12 strain RU172 were obtained by RT-PCR and direct sequencing using end primers and several internal primers, designed from conserved stretches of several published sequences.