Detection and Characterization of Porcine Sapelovirus in Italian Pig Farms

SIMPLE SUMMARY: Sapelovirus (PSV) is known to infect pigs asymptomatically but, sporadically, can cause reproductive failure and severe neurologic, enteric, or respiratory signs. Sapelovirus infections have been reported worldwide in pigs. However, information about PSV circulation in Italy is unavailable and rarely investigated across Europe. In this study, we reported the circulation of PSV in three Italian pig farms and added novel information about evolutionary heterogeneity of PSV strains showing a low genetic correlation with the other strains detected worldwide. The present study gives information about PSV circulation in intensive pig farms and highlights the need for further investigation. ABSTRACT: Porcine sapelovirus (PSV) belongs to the genus Sapelovirus of the family Picornaviridae. PSV infects pigs asymptomatically, but it can also cause severe neurologic, enteric, and respiratory symptoms or reproductive failure. Sapelovirus infections have been reported worldwide in pigs. The objective of this study was to investigate the presence and the prevalence of PSV in Italian swine farms in animals of different ages to clarify the occurrence of the infection and the genetic characteristics of circulating strains. In the present study, 92 pools of fecal samples, collected from pigs across three farms, were analyzed by Reverse Transcriptase-polymerase Chain Reaction-PCR (RT-PCR). Fecal pools from young growers (63/64) were found positive for Sapelovirus in all farms while detection in sows (4/28) was observed in only one farm. Phylogenetic analyses of the 19 partial capsid protein nucleotide sequences (VP1) (6–7 each farm) enable the classification of the virus sequences into three distinct clades and highlighted the high heterogeneity within one farm. The whole genome sequence obtained from one strain showed the highest correlation with the Italian strain detected in 2015. The study adds novel information about the circulation and heterogeneity of PSV strains in Italy and considering the movement of pigs across Europe would also be informative for other countries.