High prevalence, genetic diversity and a potentially novel genotype of Sapelovirus A (Picornaviridae) in enteric and respiratory samples in Hungarian swine farms

All of the known porcine sapeloviruses (PSVs) currently belong to a single genotype in the genus Sapelovirus (family Picornaviridae). Here, the complete genome of a second, possibly recombinant, genotype of PSV strain SZ1M-F/PSV/HUN2013 (MN807752) from a faecal sample of a paraplegic pig in Hungary was characterized using viral metagenomics and RT-PCR. This sapelovirus strain showed only 64 % nucleotide identity in the VP1 region to its closest PSV-1 relative. Complete VP1 sequence-based epidemiological investigations of PSVs circulating in Hungary showed the presence of diverse strains found in high prevalence in enteric and respiratory samples collected from both asymptomatic and paraplegic pigs from 12 swine farms. Virus isolation attempts using PK-15 cell cultures were successful in 3/8 cases for the classic but not the novel PSV genotype. Sequence comparisons of faeces and isolate strains derived VP1 showed that cultured PSV strains not always represent the dominant PSVs found in vivo.