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Abstract: Group A rotaviruses (GARVs) cause severe acute gastroenteritis in children and young animals. Although zoonotic infections with bovine-like G6 and G8 GARVs have been reported in many countries, there is little evidence for reassortment between bovine GARVs and GARVs from heterologous species. The finding of bovine GARVs with the G6 and G8 genotypes in combination with the typical porcine P[7] prompted us to characterize all 11 genes of 30 bovine GARVs isolated from clinically infected calves. By the comparison of the full-length ORF of VP7 and NSP1–5, and the partial VP1–4 and VP6 nucleotide sequences between the 30 Korean and other known strains, three different genome constellations were found. Twenty seven strains showed the G8-P[7]-I5-R1-C1-M2-A1-N1-T1-E1-H1 genotypes, a single strain possessed the G6-P[7]-I2-R2-C1-M2-A1-N2-T1-E2-H1 genotype constellation and 2 strains the G6-P[7]-I2-R2-C2-M2-A3-N2-T6-E2-H3 genotype constellation. The complete genome of a single reference strains for each of these three genotype constellations (KJ25, KJ9-1 and KJ19-2) was determined and analyzed. A detailed phylogenetic analysis revealed a complicated picture, with several reassortments among bovine-like, porcine-like and human-like GARV strains, resulting in several different reassortant strains successfully infecting cattle. [Copyright &y& Elsevier]

Abstract: Since the prevalence of bovine norovirus (BNoV) and their genetic diversity have only been reported in the USA, England, Germany and The Netherlands, this study examined the prevalence and genetic diversity of BNoVs in diarrheic calves in South Korea using 645 diarrheic fecal specimens from calves by RT-PCR and nested PCR assays. Overall, 9.3% of the diarrheic fecal samples tested positive for BNoVs by either RT-PCR or nested PCR, of which 5.9% samples also tested positive for other enteric pathogens including the bovine coronavirus, bovine viral diarrhea virus, bovine torovirus, bovine groups A, B and C rotaviruses, bovine enteric Nebraska-like calicivirus and Escherichia coli. The genetic diversity was determined by direct sequencing of the partial RdRp region of 12 BNoVs detected from the fecal samples by nested PCR. Among the BNoVs examined, one Korean BNoV strain had the highest nucleotide (86.8%) and amino acid (99.1%) identity with the genotype 1 BNoV (GIII-1) strain, while the remaining 11 Korean BNoVs shared a higher nucleotide (88.0–90.5%) and amino acid (93.5–99.1%) identity with the genotype 2 BNoV (GIII-2) strains. The phylogenetic data for the nucleotide and amino acid sequences also demonstrated that one Korean BNoV strain clustered with GIII-1 but the remaining eleven strains clustered with GIII-2. In conclusion, BNoV infections are endemic and there are two distinct genotypes with GIII-2 being the main genotype circulating in the calf population in South Korea. [Copyright &y& Elsevier]