Isolation and evolutionary analyses of porcine epidemic diarrhea virus in Asia

Wan Liang; Danna Zhou; Chao Geng; Keli Yang; Zhengying Duan; Rui Guo; Wei Liu; Fangyan Yuan; Zewen Liu; Ting Gao; Ling Zhao; Dongwan Yoo; Yongxiang Tian

doi:10.7717/peerj.10114

Isolation and evolutionary analyses of porcine epidemic diarrhea virus in Asia

PeerJ. 2020 Oct 20:8:e10114. doi: 10.7717/peerj.10114. eCollection 2020.

Authors

Wan Liang^{1

2}, Danna Zhou¹, Chao Geng^{1

3}, Keli Yang¹, Zhengying Duan¹, Rui Guo¹, Wei Liu¹, Fangyan Yuan¹, Zewen Liu¹, Ting Gao¹, Ling Zhao², Dongwan Yoo⁴, Yongxiang Tian¹

Affiliations

¹ Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China.
² Key Laboratory of Preventive Veterinary Medicine of Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
³ College of Animal Sciences, Yangtze University, Jinzhou, China.
⁴ Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, United States of America.

Abstract

Porcine epidemic diarrhea virus (PEDV) is a leading cause of diarrhea in pigs worldwide. Virus isolation and genetic evolutionary analysis allow investigations into the prevalence of epidemic strains and provide data for the clinical diagnosis and vaccine development. In this study, we investigated the genetic characteristics of PEDV circulation in Asia through virus isolation and comparative genomics analysis. APEDV strain designated HB2018 was isolated from a pig in a farm experiencing a diarrhea outbreak. The complete genome sequence of HB2018 was 28,138 bp in length. Phylogenetic analysis of HB2018 and 207 PEDVs in Asia showed that most PEDV strains circulating in Asia after 2010 belong to genotype GII, particularly GII-a. The PEDV vaccine strain CV777 belonged to GI, and thus, unmatched genotypes between CV777 and GII-a variants might partially explain incomplete protection by the CV777-derived vaccine against PEDV variants in China. In addition, we found the S protein of variant strains contained numerous mutations compared to the S protein of CV777, and these mutations occurred in the N-terminal domain of the S protein. These mutations may influence the antigenicity, pathogenicity, and neutralization properties of the variant strains.

Keywords: Amino acid mutations; Asia; Genetic evolutionary analysis; Porcine epidemic diarrhea virus; Virus isolation.

Grants and funding

This work was supported by the Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture) (grant number: KLPCAAB-YTP-1801), the open funds of the Key Laboratory of Preventive Veterinary Medicine of Hubei Province, and the China Postdoctoral Science Foundation (grant number: 2019M652609). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.