Antipathogenic Properties of Green Tea Polyphenol Epigallocatechin Gallate at Concentrations below the MIC against Enterohemorrhagic Escherichia coli O157:H7

• Published in: Journal of food protection 2009-02, Vol.72 (2), p.325-331
• Main Authors: Lee, Kang-Mu, Kim, Wan-Seok, Lim, Jeesun, Nam, Sunyoung, Youn, Min, Nam, Seong-Won, Kim, Younghoon, Kim, Sae-Hun, Park, Woojun, Park, Sungsu
• Format: Article
• Language: English
• Subjects: Animals; antibacterial properties; Antibiotics; antipathogenic effects; Bacteria; biofilm; Biofilms; Biofilms - growth & development; Biological and medical sciences; Caenorhabditis elegans; Caenorhabditis elegans - growth & development; Caenorhabditis elegans - microbiology; Catechin - analogs & derivatives; Catechin - pharmacology; cell motility; Coffee, tea and other stimulative beverage industries; Colony Count, Microbial; Dose-Response Relationship, Drug; E coli; enterohemorrhagic Escherichia coli; epigallocatechin; Escherichia coli O157 - drug effects; Escherichia coli O157 - genetics; Escherichia coli O157 - growth & development; Escherichia coli O157 - pathogenicity; Escherichia coli O157:H7; Escherichia coli Proteins - analysis; Food industries; Food microbiology; food pathogens; Food safety; Fundamental and applied biological sciences. Psychology; gallic acid; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genetic engineering; Genotype & phenotype; Glucose; Green tea; Infections; microbial growth; Microbial Sensitivity Tests; mortality; Motility; Nematodes; Pathogens; phenotype; polymerase chain reaction; Polyphenols; Quorum Sensing; Reverse Transcriptase Polymerase Chain Reaction; Salmonella; Signal Transduction; Software; Tea; Tea - chemistry; Virulence; Virulence - genetics
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028x-72.2.325

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 μg/ml, which are lower than the MIC (539 ± 22 μg/ml). At 25 μg/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 μg/ml. Our results suggest that EGCG at concentrations below its MIC has significant antipathogenic effects against E. coli O157:H7.