Sun Yingshuo, Gong Ting, Wu Dongdong, Feng Yongzhi, Gao Qi, Xing Jiabao, Zheng Xiaoyu, Song Zebu, Liu Xing, Chen Xiongnan, Sun Yankuo, Zhang Guihong, Gong Lang
Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, Guangzhou, China.
Front Microbiol. 2023 Oct 13;14:1273589. doi: 10.3389/fmicb.2023.1273589. eCollection 2023.
Porcine epidemic diarrhea (PED) is an enterophilic infectious disease caused by the porcine epidemic diarrhea virus (PEDV), which can lead to dehydration-like diarrhea in piglets with a mortality rate of up to 100%, causing huge economic losses to the global pig industry. In this study, we isolated two PEDV strains, FS202201 and JY202201, from diarrheal samples collected from two new PED outbreak farms in 2022. We performed phylogenetic analysis of the S gene and whole gene sequence. The effects of the different mutations on viral pathogenicity were investigated using piglet challenge experiments. The results showed that both strains belong to the G2c subtype, a widely prevalent virulent strain. Compared with FS202201, JY202201 harbored substitution and deletion mutations in nsp1. Both FS202201 and JY202201 infected piglets showed severe diarrhea and significant intestinal tissue lesions at an infection dose of 10 TCID/mL, with a mortality rate of 50%; however, JY202201 required an additional day to reach mortality stabilization. An infection dose of 10 TCID/mL reduced diarrhea and intestinal tissue lesions in piglets, with mortality rates of the two strains at 16.7% and 0%, respectively. In addition, PEDV was detected in the heart, liver, spleen, lungs, kidneys, mesenteric lymph nodes, stomach, large intestine, duodenum, jejunum, and ileum, with the highest levels in the intestinal tissues. In conclusion, this study enriches the epidemiology of PEDV and provides a theoretical basis for the study of its pathogenic mechanism and prevention through virus isolation, identification, and pathogenicity research on newly identified PED in the main transmission hub area of PEDV in China (Guangdong).
猪流行性腹泻(PED)是由猪流行性腹泻病毒(PEDV)引起的一种嗜肠性传染病,可导致仔猪出现类似脱水的腹泻,死亡率高达100%,给全球养猪业造成巨大经济损失。在本研究中,我们从2022年两个新发生PED疫情的猪场采集的腹泻样本中分离出两株PEDV毒株,FS202201和JY202201。我们对S基因和全基因序列进行了系统发育分析。通过仔猪攻毒实验研究了不同突变对病毒致病性的影响。结果表明,两株毒株均属于G2c亚型,是一种广泛流行的强毒株。与FS202201相比,JY202201在nsp1中存在替换和缺失突变。以10 TCID/mL的感染剂量感染仔猪时,FS202201和JY202201均表现出严重腹泻和明显的肠道组织病变,死亡率为50%;然而,JY202201需要额外一天才能达到死亡稳定状态。10 TCID/mL的感染剂量减轻了仔猪的腹泻和肠道组织病变,两株毒株的死亡率分别为16.7%和0%。此外,在心脏、肝脏、脾脏、肺脏、肾脏、肠系膜淋巴结、胃、大肠、十二指肠、空肠和回肠中均检测到PEDV,肠道组织中的含量最高。总之,本研究通过对中国PEDV主要传播枢纽地区(广东)新发现的PED进行病毒分离、鉴定和致病性研究,丰富了PEDV的流行病学,为其致病机制和预防研究提供了理论依据。