Double nomenclature of sapovirus based on complete VP1 and NS6-7
nucleotide sequences
Abstract
A significant foodborne pathogen that causes acute gastroenteritis
worldwide is sapovirus (SaV). Currently, SaV genotyping is primarily
based on the VP1 gene. The single naming method based on the VP1 region
can no longer suit the needs of SaV research due to the emergence of
recombinant strains. Therefore, SaV nucleotide sequences with entire VP1
and NS6-7 genes sections were gathered in Genbank, and genetic distance
calculations and phylogenetic analyses were carried out to investigate
the double nomenclature based on SaV VP1 and NS6-7 genes. They can be
further subdivided into genotypes and various genogroups based on the
genetic diversity of the entire VP1 region, and 12 genogroups and 30
genotypes were found, including tentative genotypes and genogroups. The
work is noteworthy for having discovered a novel genogroup, GNA1. There
was an interesting discovery of a class of sequences known as
bat-related sequences. The genetic distance between these sequences
approached the inter-genogroup genetic distance, which in this study was
classified as the bat genogroup. Thirty significant reference sequences
are proposed based on the VP1 genotypes. Phylogenetically, twelve P
(polymerase)-groups and 29 P-types (Including tentative genotypes and
genogroup) were identified based on the genetic diversity of nucleotide
sequences in the entire NS6-7 region, and related P-type reference
sequences were also suggested. Nine recombinant sequences, comprising
six recombinant genotypes (GI.1[P4], GI.2[P1], GII.4[P1],
GII.4[PNA1], GII.6[P2], and GV.NA1[P3]), were found as a
result of the dual nomenclature of the VP1 and NS6-7 genes. Dual
nomenclature based on VP1 and NS6-7 genes can effectively characterize
SaV recombination.