Porcine E. coli: virulence-associated genes, resistance genes and adhesion and probiotic activity tested by a new screening method

PLoS One. 2013 Apr 26;8(4):e59242. doi: 10.1371/journal.pone.0059242. Print 2013.

Abstract

We established an automated screening method to characterize adhesion of Escherichia coli to intestinal porcine epithelial cells (IPEC-J2) and their probiotic activity against infection by enteropathogenic E. coli (EPEC). 104 intestinal E. coli isolates from domestic pigs were tested by PCR for the occurrence of virulence-associated genes, genes coding for resistances to antimicrobial agents and metals, and for phylogenetic origin by PCR. Adhesion rates and probiotic activity were examined for correlation with the presence of these genes. Finally, data were compared with those from 93 E. coli isolates from wild boars. Isolates from domestic pigs carried a broad variety of all tested genes and showed great diversity in gene patterns. Adhesions varied with a maximum of 18.3 or 24.2 mean bacteria adherence per epithelial cell after 2 or 6 hours respectively. Most isolates from domestic pigs and wild boars showed low adherence, with no correlation between adhesion/probiotic activity and E. coli genes or gene clusters. The gene sfa/foc, encoding for a subunit of F1C fimbriae did show a positive correlative association with adherence and probiotic activity; however E. coli isolates from wild boars with the sfa/foc gene showed less adhesion and probiotic activity than E. coli with the sfa/foc gene isolated from domestic pigs after 6 hour incubation. In conclusion, screening porcine E. coli for virulence associated genes genes, adhesion to intestinal epithelial cells, and probiotic activity revealed a single important adhesion factor, several probiotic candidates, and showed important differences between E. coli of domestic pigs and wild boars.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild
  • Antibiosis / genetics*
  • Bacterial Adhesion / genetics
  • Drug Resistance, Bacterial / genetics
  • Enteropathogenic Escherichia coli / classification
  • Enteropathogenic Escherichia coli / genetics*
  • Enteropathogenic Escherichia coli / pathogenicity*
  • Epithelial Cells / cytology
  • Epithelial Cells / microbiology
  • Escherichia coli / classification
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / classification
  • Escherichia coli Proteins / genetics*
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial*
  • Genetic Variation
  • High-Throughput Screening Assays
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / microbiology
  • Multigene Family
  • Phylogeny
  • Sus scrofa
  • Swine
  • Virulence

Substances

  • Escherichia coli Proteins
  • ymcE protein, E coli

Grant support

This work was supported by InnoProfile IP 03 IP 611 funded by the Bundesministerium für Bildung und Forschung (BMBF, Germany) and by Collaborative Research Group (SFB) 852 "Nutrition and intestinal microbiota - host interactions in the pig" funded by the Deutsche Forschungsgemeinschaft (DFG). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.