Antipathogenic properties of green tea polyphenol epigallocatechin gallate at concentrations below the MIC against enterohemorrhagic Escherichia coli O157:H7

J Food Prot. 2009 Feb;72(2):325-31. doi: 10.4315/0362-028x-72.2.325.

Abstract

The inhibitory effects of green tea polyphenol epigallocatechin gallate (EGCG) on virulence phenotypes and gene expression regulated by quorum sensing (QS) in Escherichia coli O157:H7 were demonstrated at concentrations of 1 to 100 microg/ml, which are lower than the MIC (539 +/- 22 microg/ml). At 25 microg/ml, the growth rate was not affected, but autoinducer 2 concentration, biofilm formation, and swarm motility decreased to 13.2, 11.8, and 50%, respectively. Survival at 5 days of nematodes (Caenorhabditis elegans) that were fed the pathogen without and with EGCG were 47.1 and 76%, respectively. Real-time PCR data indicated decreased transcriptional level in many quorum sensing-regulated virulence genes at 25 microg/ml. Our results suggest that EGCG at concentrations below itsMIC has significant antipathogenic effects against E. coli O157:H7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biofilms / growth & development
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / microbiology*
  • Catechin / analogs & derivatives*
  • Catechin / pharmacology
  • Colony Count, Microbial
  • Dose-Response Relationship, Drug
  • Escherichia coli O157 / drug effects*
  • Escherichia coli O157 / genetics
  • Escherichia coli O157 / growth & development
  • Escherichia coli O157 / pathogenicity*
  • Escherichia coli Proteins / analysis
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial*
  • Microbial Sensitivity Tests
  • Quorum Sensing
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Tea / chemistry*
  • Virulence / genetics

Substances

  • Escherichia coli Proteins
  • Tea
  • Catechin
  • epigallocatechin gallate