Effects of (-)-epigallocatechin-3-gallate (EGCG) on the expression levels of Quorum sensing-associated genes (sdiA and luxS) in Salmonella enterica serovar Typhimurium

Background: Quorum sensing (QS) is a cell density dependent mechanism used by many pathogenic bacteria for regulating virulence gene expression. Inhibition or interruption QS by herbal remedies has been suggested as a new strategy for fighting against antibiotic resistant bacteria. The goal of this study was to assess the impact of subinhibitory concentrations of natural plant product (-)-epigallocatechin-3-gallate (EGCG) on the luxS and sdiA genes expression. Methods: The quantitative real time PCR (qRT-PCR) assay was used to analyze the expression of sdiA and luxS in 23 S. Typhimurium strains isolated from poultry flocks in response to the treatment of subinhibitory concentrations of EGCG and LAA at one-time point 45 min. Results: EGCG showed good in vitro antibacterial activity against all 23 tested S. Typhimurium strains in this experiment. The results also indicate that the expression of QS-related genes was reduced in S. Typhimurium strains triggered by the treatment of EGCG comparatively with those from control cultures. Conclusion: Findings suggest that EGCG possess the anti-quorum sensing activity and can be used to control the expression of virulence genes in pathogenic bacteria, such as S. Typhimurium.

Effects of (-)-epigallocatechin-3-gallate (EGCG) on the expression levels of Quorum sensing-associated genes (sdiA and luxS) in Salmonella enterica serovar Typhimurium Keywords:

(-)-epigallocatechin-3-gallate , luxS and sdiA gene , qRT-PCR , S. Typhimurium