Isolation and characterization of a variant porcine epidemic diarrhea virus in China

Virol J. 2012 Sep 12:9:195. doi: 10.1186/1743-422X-9-195.

Abstract

An outbreak of diarrhea in pigs started in Guangdong, South China in January 2011. Cases were characterized by watery diarrhea, dehydration and vomiting, with 80-100% morbidity and 50-90% mortality in suckling piglets. The causative agent of the diarrhea was ultimately identified as porcine epidemic diarrhea virus (PEDV). In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. The complete genome of CHGD-01 was shown to be 28,035 nucleotides in length, with a similar structure to that of PEDV reference strains. Phylogenetic analyses based on the whole genome revealed that CHGD-01 shared nucleotide sequence identities of 98.2-98.4% with two other Chinese isolates reported in the same year, thus constituting a new cluster. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Its ORF3 and nucleoprotein genes, however, were divergent from all other sequenced PEDV isolate clusters and therefore formed a new group, suggesting a new variant PEDV isolate in China. Further studies will be required to determine the immunogenicity and pathogenicity of this new variant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Coronavirus Infections / veterinary
  • Cytopathogenic Effect, Viral
  • Genes, Viral
  • Molecular Sequence Data
  • Phylogeny
  • Porcine epidemic diarrhea virus / classification
  • Porcine epidemic diarrhea virus / genetics*
  • Porcine epidemic diarrhea virus / isolation & purification*
  • Sequence Alignment
  • Swine
  • Swine Diseases / epidemiology
  • Swine Diseases / virology

Associated data

  • GENBANK/JX261936