Metagenomic identification, genetic characterization and genotyping of porcine sapoviruses.

Sapoviruses (SaVs), belonging to the genus Sapovirus of the family Caliciviridae, were known as the enteric pathogen causing acute gastroenteritis. SaVs have been detected in humans and several animals including pigs and some porcine SaVs showed close sequence relationship with human strains suggesting the possibility of interspecies transmission. Here, we sequenced the genomes of two porcine SaVs (with strain names of p38 and SH1703) using the metagenomic analyses and traditional RT-PCR methods. Phylogenetic trees were constructed based on the complete genome, the full-length VP 1 nucleotide and amino acid sequences to group those two strains. The two porcine SaV strains, p38 and SH1703, detected in this study, were classified as genogroup III and genogroup VII, respectively. These two strains showed similar genomic organization with that of other SaVs. We firstly divided SaVs into 51 genotypes within 19 genogroups. Our data are helpful for genetic characterization and classification of newly detected SaVs worldwide.