Mawatari Takahiro, Hirano Kaori, Tsunemitsu Hiroshi, Suzuki Tohru
Yamagata Prefectural Central Livestock Health and Sanitation Office, Yamagata, 990-2161 Japan.
Dairy Hygiene Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Hokkaido, 062-0045 Japan.
J Gen Virol. 2014 May;95(Pt 5):1117-1125. doi: 10.1099/vir.0.062166-0. Epub 2014 Jan 31.
An epidemic of diarrhoea in adult cows occurred at a total of 105 dairy farms in Yamagata Prefecture, Japan, between 2003 and 2010. Reverse transcription-PCR diagnostic tests revealed the presence of bovine rotavirus species C (RVCs) in samples from each of six farms (5.7 %). In this study, we determined the full-length nucleotide sequences of 11 RNA segments from six bovine RVC strains and investigated genetic diversity among them, including two bovine RVC strains identified in a previous study. Comparisons of all segmental nucleotide and the deduced amino acid sequences among bovine RVCs indicated high identities across all genes except for the VP4 gene. Phylogenetic analysis of each gene revealed that the six bovine RVCs belonged to a bovine cluster distinct from human and porcine RVCs. Bovine RVC strains could be clearly divided into two lineages of the VP4 genes. The nucleotide sequence identity for VP4 genes between lineage I and II was 83.7-84.8 %. Moreover, bovine RVC strains belonging to lineage I exhibited one amino acid deletion and three amino acid insertions, which differed for those strains belonging to lineage II. Our data suggest that multiple bovine RVCs originated from a common ancestor, but had different genetic backgrounds, not only in Yamagata Prefecture but also in the rest of Japan.
2003年至2010年期间，日本山形县共有105个奶牛场发生成年奶牛腹泻疫情。逆转录聚合酶链反应诊断测试显示，六个农场（5.7%）的样本中均存在牛轮状病毒C型（RVCs）。在本研究中，我们测定了6株牛RVC毒株11个RNA片段的全长核苷酸序列，并研究了它们之间的遗传多样性，其中包括先前研究中鉴定的2株牛RVC毒株。牛RVCs所有片段核苷酸和推导氨基酸序列的比较表明，除VP4基因外，所有基因的同源性都很高。对每个基因的系统发育分析表明，这6株牛RVCs属于一个与人和猪RVCs不同的牛群。牛RVC毒株可根据VP4基因明显分为两个谱系。谱系I和II的VP4基因核苷酸序列同一性为83.7%-84.8%。此外，属于谱系I的牛RVC毒株表现出一个氨基酸缺失和三个氨基酸插入，这与属于谱系II的毒株不同。我们的数据表明，多种牛RVCs起源于一个共同祖先，但不仅在山形县，而且在日本其他地区都有不同的遗传背景。
