Genetic characterization and phylogenetic analysis of porcine epidemic diarrhea virus in Guangdong, China, between 2018 and 2019

PLoS One. 2021 Jun 24;16(6):e0253622. doi: 10.1371/journal.pone.0253622. eCollection 2021.

Abstract

Porcine epidemic diarrhea virus (PEDV), a leading cause of piglet diarrhea outbreaks, poses a significant danger to the swine industry. The aim of this study was to investigate the epidemic characteristics of PEDV that was circulating in Guangdong province, one of China's major pig producing provinces. Clinical samples were collected from eight pig farms in Guangdong province between 2018 and 2019 and tested for the major porcine enteric pathogens, including PEDV, transmissible gastroenteritis virus (TGEV), Swine enteric coronavirus (SeCoV), Swine acute diarrhea syndrome coronavirus (SADS-CoV), porcine deltacoronavirus (PDCoV), and porcine rotavirus (RV). As a result, only PEDV and RV were detected at a rate of 47.0% (16/34) and 18.6% (8/34), respectively. Coinfectoin with PEDV and RV occurred at a rate of PEDV 12.5% (2/16). Subsequently, the full-length S gene sequences of 13 PEDV strains were obtained, and phylogenetic analysis suggested the presence of GII-c group PEDV strains in this region (non-S-INDEL). Two novel common amino acid insertions (55T/IG56 and 551L) and one novel glycosylation site (1199G+) were detected when the CV777 and ZJ08 vaccine strains were compared. Furthermore, intragroup recombination events in the S gene regions 51-548 and 2478-4208 were observed in the PEDV strains studied. In summary, the observations provide current information on the incidence of viral agents causing swine diarrhea in southern China and detailed the genetic characteristics and evolutionary history of the dominant PEDV field strains. Our findings will aid in the development of an updated vaccine for the prevention and control of PEDV variant strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alphacoronavirus / genetics
  • Animals
  • China / epidemiology
  • Coronavirus Infections / epidemiology
  • Coronavirus Infections / genetics*
  • Disease Outbreaks*
  • Phylogeny*
  • Porcine epidemic diarrhea virus / genetics*
  • Swine
  • Swine Diseases / epidemiology
  • Swine Diseases / genetics*
  • Transmissible gastroenteritis virus / genetics

Supplementary concepts

  • Swine acute diarrhea syndrome coronavirus

Grants and funding

This study was supported by National Key R&D Program of China (2018YFD0501200); National Natural Science Foundation of China (Grant No. 32002320); Guangdong Basic and Applied Basic Research Foundation (Grant No. 2020A1515010116 and 2019A1515110785). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.