Isolation, identification, and pathogenicity of porcine epidemic diarrhea virus

Yingshuo Sun; Ting Gong; Dongdong Wu; Yongzhi Feng; Qi Gao; Jiabao Xing; Xiaoyu Zheng; Zebu Song; Xing Liu; Xiongnan Chen; Yankuo Sun; Guihong Zhang; Lang Gong

doi:10.3389/fmicb.2023.1273589

Isolation, identification, and pathogenicity of porcine epidemic diarrhea virus

Front Microbiol. 2023 Oct 13:14:1273589. doi: 10.3389/fmicb.2023.1273589. eCollection 2023.

Authors

Yingshuo Sun^#^{1

2}, Ting Gong^#^{1

3}, Dongdong Wu^{1

2}, Yongzhi Feng^{1

3}, Qi Gao^{1

3}, Jiabao Xing^{1

2}, Xiaoyu Zheng^{1

3}, Zebu Song^{1

3}, Xing Liu¹, Xiongnan Chen^{1

3}, Yankuo Sun^{1

3}, Guihong Zhang^{1

2

3}, Lang Gong^{1

2

3}

Affiliations

¹ Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
² Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, Guangzhou, China.
³ Zhaoqing Branch Center of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Zhaoqing, China.

^# Contributed equally.

Abstract

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 10⁴ TCID₅₀/mL, with a mortality rate of 50%; however, JY202201 required an additional day to reach mortality stabilization. An infection dose of 10³ TCID₅₀/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).

Keywords: identification; mutation; nsp1; pathogenicity; porcine epidemic diarrhea virus.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by the National Key Research and Development Program of China (2022YFD1800804), the National Key Research and Development Program of China (2022YFD1802103), and the China Agriculture Research System of MOF and MARA (cars-35).