title: Full genomic analyses of human rotavirus strains possessing the rare P[8]b VP4 subtype.
abstract: Rotaviruses with the P[8] VP4 genotype are a major cause of acute infantile diarrhea. The P[8] genotype is classified into two genetically distinct subtypes, P[8]a and P[8]b. Most of the P[8] strains belong to subtype P[8]a, whilst P[8]b strains are rare. To date, the whole genomes of a few P[8]a strains have been analyzed, whilst there are no reports on full genomic analysis of the P[8]b strains. To determine the genetic makeup of the rare P[8]b strains and their overall genetic relatedness to the P[8]a strains, the present study analyzed the full genomes of a human G9P[8]b strain, MMC38, and a G1P[8]b strain, MMC71, detected in Bangladesh in 2005. By nucleotide sequence identities and phylogenetic analyses, strains MMC38 and MMC71 exhibited a human rotavirus Wa-like genotype constellation. Except for the VP4 gene, all the genes of strains MMC38 and MMC71 were closely related to cognate genes of the contemporary and more recent human Wa-like G1P[8]a, G9P[8]a, G11P[8]a, G11P[25], G12P[6] and G12P[8]a strains, including those from Bangladesh. Therefore, strains MMC38 and MMC71 possessed the genetically distinct P[8]b VP4 gene on a common human Wa-like genetic backbone, pointing towards their possible origin from reassortment events between common human Wa-like strains and unidentified rotavirus strains possessing the rare P[8]b-like VP4 gene. Since strains with this stable Wa-like genetic backbone can spread rapidly, and it is not certain as to whether the current rotavirus vaccines will be equally efficacious against the P[8]b strains as the P[8]a strains, proper detection of P[8]b strains and their whole genomic analyses might be of public health significance. To our knowledge, the present study is the first report on full genomic analysis of the rare P[8]b rotavirus strains.
authors.affiliation: Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. souvik8@rediffmail.com
authors.forename: Souvik
authors.initials: S
authors.lastname: Ghosh
authors.forename: Shyamal Kumar
authors.initials: SK
authors.lastname: Paul
authors.forename: Dai
authors.initials: D
authors.lastname: Yamamoto
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nagashima
authors.forename: Nobumichi
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D005243:Feces / Q000821:virology; D016679:Genome, Viral; D005838:Genotype; D006801:Humans; D007223:Infant; D010802:Phylogeny; D012401:Rotavirus / Q000145:classification / Q000235:genetics*; D012400:Rotavirus Infections / Q000821:virology*; D017423:Sequence Analysis, RNA; D012689:Sequence Homology, Nucleic Acid; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins