Molecular characterisation of a novel avian rotavirus A strain detected from a gull species (Larus sp.)

Molecular characterization of an avian rotavirus a strain detected from a large-billed crow (Corvus macrorhynchos) in Japan

Avian rotaviruses A (RVAs) are occasionally transmitted to animals other than the original hosts across species barriers. Information on RVAs carried by various bird species is important for identifying the origin of such interspecies transmission. In this study, to facilitate an understanding of the ecology of RVAs from wild birds, we characterized all of the genes of an RVA strain, JC-105, that was detected in a fecal sample of a large-billed crow (Corvus macrorhynchos) in Japan. All of the genes of this strain except for the VP4 and VP7 genes, which were classified as novel genotypes (P[56] and G40, respectively), were closely related to those of the avian-like RVA strain detected from a raccoon, indicating the possibility that crows had been involved in the transmission of avian RVAs to raccoons. Our findings highlight the need for further viral investigations in wild birds and mammals to understand the mechanisms of avian-to-mammal RVA transmission.

First report of the whole-genome sequence analysis of avian rotavirus A from Japanese chickens

Rotavirus A infects many mammalian species, including humans and causes diarrhea and gastrointestinal diseases. The virus also infects various bird species, including chickens, although information of avian rotavirus A (ARVA) infection in chicken populations in Japan is scarce. In this study, we report for the first time the whole-genome sequences of ARVA strains from Japanese chicken populations. The virus strains were inoculated to MA104 cells and cultured viruses were used to obtain the sequences with the MiSeq system, and genetic analysis demonstrated the genotype constellation of G19-P[30]-I11-R6-C6-M7-A16-N6-T8-E10-H8 of the Japanese chicken ARVA isolates. Phylogenetic analyses demonstrated that the VP1, VP2, VP3, VP4, VP7, NSP2, and NSP4 coding gene sequences of the Japanese strains were closer to those of Korean than the European ARVA strains, although such relationship was not clear for other genes. The data suggest that the Japanese ARVA strains and the ones in Korea have genetically close relationship, although the origin is not clear at this point. Further information including the whole-genome sequences of the Korean strains and sequences of other Japanese chicken ARVA strains will be necessary for elucidation of their origin.