Characterization and phylogenetic analysis of a novel picornavirus from swine feces in Japan.

During an investigation of porcine fecal viruses using a metagenomics approach, a novel picornavirus was identified from the feces of a healthy two-month-old pig. This virus, named porcine picornavirus Japan (PPVJ), had a standard picornavirus genome organization, including the L protein region. The 5' untranslated region harbored a type II internal ribosomal entry site. This virus was most closely related to lesavirus 1 (amino acid sequence identity: 38.2 %) in P1, equine rhinitis A virus (25.8 %) in P2, and lesavirus 2 (40.9 %) in P3. According to the genus demarcations for the family Picornaviridae (less than 40 %, 40 %, and 50 % amino acid sequence identity in P1, P2, and P3, respectively), PPVJ represents a new genus in the family Picornaviridae. PPVJ was detected in 23.3 % of the fecal samples (from 58.3 % of the farms across a wide area) from pigs less than four months old, by reverse transcription PCR, using specific primers designed from the 3D sequence, followed by sequencing. The host range and pathogenic potential of this virus in animals is yet to be determined.