Su Mingjun, Wang Yutao, Yan Junfang, Xu Xiangwen, Zheng Huihua, Cheng Jiongze, Du Xiaoxu, Liu Yijia, Ying Jiale, Zhao Yulin, Wang Ziqi, Duan Xing, Yang Yang, Cheng Changyong, Ye Zhihui, Sun Jing, Sun Dongbo, Song Houhui
Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, Zhejiang Province, China.
Ningbo Creator Animal Pharmaceutical Co. Ltd, Ningbo, Zhejiang Province, PR China.
Virulence. 2024 Dec;15(1):2397512. doi: 10.1080/21505594.2024.2397512. Epub 2024 Sep 16.
Porcine epidemic diarrhea virus (PEDV) causes diarrhea and vomiting in piglets, leading to a mortality rate of 100%. Due to the high frequency of mutation, it is important to monitor the evolution of PEDV and develop potential vaccine candidates. In this study, two PEDV strains (ZJ2022 and ZQ2022) were identified by PCR. These strains were subsequently isolated, and their genome sequences, growth characteristics, and pathogenicity were compared. Phylogenetic and recombination analyses revealed that both strains belonged to GIIa-subgroup, and ZQ2022 was identified as a recombinant strain derived from ZJ2022. Further sequence analysis showed that the ZJ2022 strain had a modified top region of the S1 protein due to a three amino acid insertion (T380_Y380insGGE) in the S1 gene. According to the virus growth curve, ZJ2022 exhibited better cellular adaptation than ZQ2022, with higher viral titers from 8 hpi to 24 hpi. Additionally, ZQ2022 exhibited a high level of pathogenicity, causing severe diarrhea in piglets at 36 hpi and a 100% mortality rate by 96 hpi. In contrast, ZJ2022 showed lower pathogenicity, inducing severe diarrhea in piglets at 60 hpi, with a mortality rate of 60% at 96 hpi and 100% at 120 hpi. In summary, our findings provided evidence of the undergoing mutations in Chinese PEDV strains. Furthermore, the S gene insertion strain ZJ2022 exhibited strong cellular adaptability and low pathogenicity, making it a potential candidate strain for vaccine development.
猪流行性腹泻病毒（PEDV）可导致仔猪腹泻和呕吐，死亡率达100%。由于其高突变频率，监测PEDV的进化并开发潜在的候选疫苗很重要。在本研究中，通过PCR鉴定出两株PEDV毒株（ZJ2022和ZQ2022）。随后分离出这些毒株，并比较了它们的基因组序列、生长特性和致病性。系统发育和重组分析表明，两株毒株均属于GIIa亚群，且ZQ2022被鉴定为源自ZJ2022的重组毒株。进一步的序列分析表明，由于S1基因中三个氨基酸插入（T380_Y380insGGE），ZJ2022毒株的S1蛋白顶部区域发生了改变。根据病毒生长曲线，ZJ2022比ZQ2022表现出更好的细胞适应性，在感染后8小时至24小时病毒滴度更高。此外，ZQ2022表现出高致病性，在感染后36小时导致仔猪严重腹泻，到96小时死亡率达100%。相比之下，ZJ2022致病性较低，在感染后60小时诱导仔猪严重腹泻，96小时死亡率为60%，120小时死亡率为100%。总之，我们的研究结果为中国PEDV毒株正在发生的突变提供了证据。此外，S基因插入毒株ZJ2022表现出强大的细胞适应性和低致病性，使其成为疫苗开发的潜在候选毒株。
