A Porcine Epidemic Diarrhea Virus Isolated from a Sow Farm Vaccinated with CV777 Strain in Yinchuan, China: Characterization, Antigenicity, and Pathogenicity
A Porcine Epidemic Diarrhea Virus Isolated from a Sow Farm Vaccinated with CV777 Strain in Yinchuan, China: Characterization, Antigenicity, and Pathogenicity
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DOI：
10.1155/2023/7082352
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发表时间：
2023-03
影响因子：
4.3
通讯作者：
Jianlin Lei;Yongqiang Miao;Zhao Guan;Hui Chen;Chaohui Xiang;Hangqi Lu;Yuan Fang;Yu Han
中科院分区：
文献类型：
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作者：
Jianlin Lei;Yongqiang Miao;Zhao Guan;Hui Chen;Chaohui Xiang;Hangqi Lu;Yuan Fang;Yu Han
猪流行性腹泻病毒（Porcine epidemic diarrhea virus，PEDV）是一种全球性的猪肠道冠状病毒，自2010年以来给全球养猪业造成了严重的经济损失。在此，PEDV CH/Yinchuan/2021株是在CV 777疫苗接种的母猪场中分离的，该母猪场于2021年在中国银川经历了大规模的PEDV入侵。结果表明，CH/Yinchuan/2021分离株可以在Vero细胞中高效繁殖，传10代（P10）时其增殖能力弱于CV 777。系统发育分析表明，CH/Yinchuan/2021与2020-2021分离株组成GIIa亚群，形成独立的分支。此外，GII明显分为4个分支，显示PEDV全球分离物的地域和时间差异。值得注意的是，CH/Yinchuan/2021被分析为源自美国分离物和中国分离物的重组体，具有跨越ORF 1a和S1的大重组区域。重要的是，我们发现CH/Yinchuan/2021相对于CV 777在中和表位（S10、S1 A、COE和SS 6）上具有多个突变。同源性建模表明，S蛋白中的这些氨基酸差异发生在其结构的表面，特别是在S10表位处的多个连续残基的插入和缺失。此外，交叉中和分析证实CH/Yinchuan/2021与CV 777株相比，S蛋白的差异改变了其抗原性，导致中和谱不同。动物致病性试验表明，CH/Yinchuan/2021对3日龄仔猪的致病性表现为PEDV典型症状，死亡率为100%。这些数据将为了解PEDV在中国的流行病学、分子特征、进化和抗原性提供有价值的信息。
Porcine epidemic diarrhea virus (PEDV) is a porcine enteric coronavirus globally, causing serious economic losses to the global pig industry since 2010. Here, a PEDV CH/Yinchuan/2021 strain was isolated in a CV777-vaccinated sow farm which experienced a large-scale PEDV invasion in Yinchuan, China, in 2021. Our results demonstrated that the CH/Yinchuan/2021 isolate could efficiently propagate in Vero cells, and its proliferation ability was weaker than that of CV777 at 10 passages (P10). Phylogenetic analysis of the S gene revealed that CH/Yinchuan/2021 was clustered into subgroup GIIa, forming an independent branch with 2020-2021 isolates in China. Moreover, GII was obviously allocated into four clades, showing regional and temporal differences in PEDV global isolates. Notably, CH/Yinchuan/2021 was analyzed as a recombinant originated from an American isolate and a Chinese isolate, with a big recombinant region spanning ORF1a and S1. Importantly, we found that CH/Yinchuan/2021 harbored multiple mutations relative to CV777 in neutralizing epitopes (S10, S1A, COE, and SS6). Homology modelling showed that these amino acid differences in S protein occur on the surface of its structure, especially the insertion and deletion of multiple consecutive residues at the S10 epitope. In addition, cross-neutralization analysis confirmed that the differences in the S protein of CH/Yinchuan/2021 changed its antigenicity compared with the CV777 strain, resulting in a different neutralization profile. Animal pathogenicity test showed that CH/Yinchuan/2021 caused PEDV-typified symptoms and 100% mortality in 3-day-old piglets. These data will provide valuable information to understand the epidemiology, molecular characteristics, evolution, and antigenicity of PEDV circulating in China.