巴西野生型牛呼吸道合胞病毒的分子特征揭示了该病毒的遗传多样性和一个可能的新亚群。

Molecular characterization of Brazilian wild-type strains of bovine respiratory syncytial virus reveals genetic diversity and a putative new subgroup of the virus.

机构信息

National Institute of Science and Technology of Dairy Production Chain (INCT-Leite), Universidade Estadual de Londrina, Paraná, Brazil.

Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.

出版信息

Vet Q. 2020 Dec;40(1):83-96. doi: 10.1080/01652176.2020.1733704.

Bovine orthopneumovirus, formerly known as bovine respiratory syncytial virus (BRSV), is frequently associated with bovine respiratory disease (BRD). To perform the molecular characterization of the G and F proteins of Brazilian wild-type BRSV strains derived from bovine respiratory infections in both beef and dairy cattle. Ten BRSV strains derived from a dairy heifer rearing unit ( = 3) in 2011 and steers of three other feedlots ( = 7) in 2014 and 2015 were analyzed. For the BRSV G and F partial gene amplifications, RT-nested-PCR assays were performed with sequencing in both directions with forward and reverse primers used. The G gene-based analysis revealed that two strains were highly similar to the BRSV sequences representative of subgroup III, including the Bayovac vaccine strain. However, the remaining seven Brazilian BRSV strains were diverse when compared with strains representative of the BRSV I to VIII subgroups. The central hydrophobic region of the Brazilian BRSV G gene showed the replacement of conserved cysteines and other residues of importance to antibody reactivity. The deduced F gene amino acid sequences from the Brazilian BRSV strains showed changes that were absent in the representative sequences of the known subgroups. Viral isolation on the nasopharyngeal swab suspensions failed to isolate BRSV. Results suggest that these strains represent a putative new subgroup of BRSV with mutations observed in the immunodominant region of the G protein. However, further studies on these Brazilian BRSV strains should be performed to establish their pathogenic potential.

牛呼吸道合胞体病毒（Bovine orthopneumovirus），以前称为牛呼吸道合胞体病毒（Bovine respiratory syncytial virus，BRSV），常与牛呼吸道疾病（Bovine respiratory disease，BRD）有关。对源自牛传染性BRD 的巴西野生型 BRSV 株的 G 和 F 蛋白进行分子特征分析。分析了源自一个 2011 年奶牛育成场的后备牛（ = 3）和另外三个牛群的育肥牛（ = 7）的 10 株 BRSV 株。使用 RT-巢式 PCR 检测方法对 BRSV G 和 F 部分基因进行扩增，并用正向和反向引物进行双向测序。基于 G 基因的分析表明，两种菌株与代表亚组 III 的 BRSV 序列高度相似，包括 Bayovac 疫苗株。然而，与代表 BRSV I 至 VIII 亚组的菌株相比，其余 7 株巴西 BRSV 株存在差异。巴西 BRSV G 基因的中心疏水区显示保守半胱氨酸和其他对抗体反应性重要的残基的取代。从巴西 BRSV 株推导的 F 基因氨基酸序列显示出与已知亚组的代表序列中不存在的变化。在鼻咽拭子悬液中进行病毒分离未能分离出 BRSV。结果表明，这些菌株代表了 BRSV 的一个新假定亚组，在 G 蛋白的免疫显性区观察到突变。然而，应该对这些巴西 BRSV 株进行进一步研究，以确定其致病潜力。