Laboratory for the Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinfeng Road, Sartu District, Daqing 163319, China; Branch of Animal Husbandry and Veterinary of Heilongjiang Academy of Agricultural Sciences, Qiqihar 161000, China.
Laboratory for the Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinfeng Road, Sartu District, Daqing 163319, China.
Virus Res. 2022 Jan 15;308:198632. doi: 10.1016/j.virusres.2021.198632. Epub 2021 Nov 15.
In 2020, to trace the prevalence and evolution of bovine coronavirus (BCoV) in China, a total of 1383 samples (1016 fecal samples and 367 nasal swab samples) were collected from 1016 cattle exhibiting diarrhea symptoms on dairy farms and beef cattle farms in Heilongjiang Province, Northeast China. All samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR) detection of the BCoV N gene, followed by an analysis of its epidemiology and genetic evolution. The results indicated that of the 1016 diarrhea-affected cattle, 15.45% (157/1016) were positive for BCoV, in which positive rates of the fecal and nasal swab samples were 12.20% (124/1016) and 21.53% (79/367), respectively. Of the 367 cattle whose nasal swab samples were collected, the BCoV positive rate of the corresponding fecal samples was 15.26% (56/367). BCoV infection was significantly associated with age, farming pattern, cattle type, farm latitude, sample type, and clinical symptom (p < 0.05). Of the 203 BCoV-positive samples, 20 spike (S) genes were successfully sequenced. The 20 identified BCoV strains shared nucleotide homologies of 97.7-100.0%, and their N-terminal domain of S1 subunit (S1-NTD: residues 15-298) differed genetically from the reference strains of South Korea and Europe. The 20 identified BCoV strains were clustered in the Asia-North America group (GII group) in the global strain-based phylogenetic tree and formed three clades in the Chinese strain-based phylogenetic tree. The HLJ/HH-10/2020 strain was clustered into the Europe group (GI group) in the S1-NTD-based phylogenetic tree, exhibiting N/I, D/G, and L/F mutations that affect the S protein structure. Of the identified BCoV strains, one potential recombination event occurred between the HLJ/HH-20/2020 and HLJ/HH-10/2020 strains, which led to the generation of the recombinant BCV-AKS-01 strain. A selective pressure analysis on the S protein revealed one positively selected site (Asn) among the 20 identified BCoV strains located inside the putative receptor binding domain (residues 326-540). These data provide a greater understanding of the epidemiology and evolution of BCoV in China.
2020 年，为了追溯中国牛冠状病毒（BCoV）的流行情况和进化情况，我们从中国东北地区黑龙江省的奶牛养殖场和肉牛养殖场中，采集了 1016 头出现腹泻症状的牛共 1383 份样本（1016 份粪便样本和 367 份鼻拭子样本），对其进行了牛冠状病毒 N 基因的反转录-聚合酶链反应（RT-PCR）检测，并对其流行病学和遗传进化进行了分析。结果表明，在 1016 头腹泻牛中，15.45%（157/1016）为 BCoV 阳性，粪便和鼻拭子样本的阳性率分别为 12.20%（124/1016）和 21.53%（79/367）。在采集鼻拭子样本的 367 头牛中，相应粪便样本的 BCoV 阳性率为 15.26%（56/367）。BCoV 感染与年龄、养殖模式、牛种、农场纬度、样本类型和临床症状显著相关（p<0.05）。在 203 份 BCoV 阳性样本中，成功测序了 20 个刺突（S）基因。20 株鉴定的 BCoV 株的核苷酸同源性为 97.7-100.0%，其 S1 亚单位的 N 端结构域（S1-NTD：残基 15-298）在遗传上与韩国和欧洲的参考株不同。20 株鉴定的 BCoV 株在基于全球株的系统进化树上聚类在亚洲-北美组（GII 组）中，并在基于中国株的系统进化树上形成三个分支。HLJ/HH-10/2020 株在基于 S1-NTD 的系统进化树上聚类到欧洲组（GI 组），表现出影响 S 蛋白结构的 N/I、D/G 和 L/F 突变。在鉴定的 BCoV 株中，HLJ/HH-20/2020 和 HLJ/HH-10/2020 株之间发生了一次潜在的重组事件，导致了重组 BCoV-AKS-01 株的产生。对 S 蛋白进行的选择压力分析表明，在 20 株鉴定的 BCoV 株中，一个位于假定受体结合域（残基 326-540）内的正选择位点（Asn）。这些数据提供了对中国 BCoV 流行病学和进化的更深入了解。
