Detection and phylogenetic analysis of porcine bocaviruses carried by murine rodents and house shrews in China

Bocaparvovirus infections of humans and both wild and domestic animals have been widely reported around the world. In this study, we detected and genetically characterized porcine bocavirus (PBoV) carried by murine rodents (Rattus norvegicus, Rattus tanezumi, and Rattus losea) and house shrews (Suncus murinus) in China. Between May 2015 and May 2017, 496 murine rodents and 23 house shrews were captured in four Chinese provinces. Nested polymerase chain reaction was used to investigate the prevalence of PBoV in throat swab, faecal and serum samples. A total of 7.5% (39/519) throat swab samples, 60.5% (309/511) faecal samples, and 22.9% (52/227) serum samples were PBoV-positive. The prevalence among R. norvegicus and R. tanezumi was higher than that among R. losea and house shrews. PBoV-positive samples were found in all four provinces. Phylogenetic analysis based on partial viral capsid protein 1/2 (VP1/VP2) showed that sequences obtained in this study formed a novel group (PBoV G4). In addition, five near full-length PBoV genomes (4,715-4,798 nt) were acquired. These genomes encoded two non-structural proteins, NS1 (1,908 nt in four genomes and 1,923 nt in the remaining genome) and NP1 (600 nt), and the structural proteins, VP1/VP2 (1,851 nt). Phylogenetic analysis showed that PBoV G4 is distinct from rodent, human, and other bocaviruses. In conclusion, PBoV G4 prevalence was high among two common murine rodents in China, and the pathogenecity of PBoV G4 need to be further clarified.