Viral metagenomics analysis of picobirnavirus-positive feces from children with sporadic diarrhea in China

Picobirnaviruses (PBVs) infect humans and a wide range of animals and may cause diarrhea. The aim of this study was to investigate PBV infection and its association with diarrhea. Here, seven PBV RT-PCR-positive fecal samples from diarrheic children and four fecal samples from healthy children as controls were analyzed by viral metagenomics. The results indicated that all the seven diarrheic fecal samples contain high titers of PBV sequences, while three of the controls were negative, and one had low titers of PBV. Three of the diarrheic fecal samples were also positive for other viruses, including anellovirus, human gyrovirus, human parechovirus, and porcine stool-associated circular virus. PBV sequences from the seven patients were assembled, generating seven large contigs with the complete ORF of RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis of the amino acid sequences of RdRp indicated that the seven PBVs in the present study belonged to three different genogroups. Our data suggest that PBV might have been the cause of diarrhea in these seven children.