National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
Tokachi Livestock Hygiene Service Center, Obihiro, Hokkaido, Japan.
J Vet Diagn Invest. 2021 Jan;33(1):162-166. doi: 10.1177/1040638720975364. Epub 2020 Nov 24.
Bovine respiratory syncytial virus (BRSV) is an etiologic agent of bovine respiratory disease. The rapid evolutionary rate of BRSV contributes to genetic and antigenic heterogeneity of field strains and causes occasional vaccine failure. We conducted molecular epidemiologic characterization of BRSV circulating in Japan to obtain genetic information for vaccine-based disease control. Phylogenetic analysis of and gene sequences revealed that all of the isolated Japanese BRSV strains clustered in the same genetic subgroup, which was distinct from the 9 known groups. We assigned the Japanese group to subgenotype X. The Japanese isolates formed 2 temporal clusters: isolates from 2003 to 2005 clustered in lineage A; isolates from 2017 to 2019 formed lineage B. The alignment of the deduced amino acid sequences of the gene revealed that the central hydrophobic region responsible for viral antigenicity is conserved in all of the isolates; unique amino acid mutations were found mainly in mucin-like regions. Our results suggest that BRSV has evolved uniquely in Japan to form the new subgenotype X; the antigenic homogeneity of the viruses within this group is inferred.
牛呼吸道合胞体病毒（Bovine respiratory syncytial virus，BRSV）是牛呼吸道疾病的病原体。BRSV 的快速进化率导致了田间毒株的遗传和抗原异质性，并导致偶尔的疫苗失败。我们对日本流行的 BRSV 进行了分子流行病学特征分析，以获得基于疫苗的疾病控制的遗传信息。和基因序列的系统进化分析显示，所有分离的日本 BRSV 株都聚集在相同的遗传亚群中，与已知的 9 个群不同。我们将日本群分配到亚基因组 X。日本分离株形成了 2 个时间聚类：2003 年至 2005 年的分离株聚集在线粒体 A 中；2017 年至 2019 年的分离株形成线粒体 B。的推导氨基酸序列的比对显示，负责病毒抗原性的中央疏水区在所有分离株中都保守；主要在粘蛋白样区域发现独特的氨基酸突变。我们的结果表明，BRSV 在日本独特进化形成新的亚基因组 X；推断该组内病毒的抗原同源性。
