Tea catechin epigallocatechin gallate inhibits Streptococcus mutans biofilm formation by suppressing gtf genes

Xin Xu,Xue D Zhou,Christine D Wu

doi:10.1016/j.archoralbio.2011.10.021

Xin Xu, Xue D Zhou + Show 1 more

Open Access

https://doi.org/10.1016/j.archoralbio.2011.10.021

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Abstract

ObjectiveThe anti-cariogenic properties of tea have been suggested for decades. Tea polyphenols, especially epigallocatechin gallate (EGCG), have been shown to inhibit dental plaque accumulation, but the exact mechanisms are not clear at present. We hypothesise that EGCG suppresses gtf genes in Streptococcus mutans at the transcriptional level disrupting the initial attachment of S. mutans and thus the formation of mature biofilms. DesignIn this study, the effect of EGCG on the sucrose-dependent initial attachment of S. mutans UA159 in a chemically defined medium was monitored over 4h using a chamber slide model. The effects of EGCG on the aggregation and gtf B, C, D gene expression of S. mutans UA159 were also examined. ResultsIt was found that EGCG (7.8–31.25μg/ml) exhibited dose-dependent inhibition of the initial attachment of S. mutans UA159. EGCG did not induce cellular aggregation of S. mutans UA159 at concentrations less than 78.125μg/ml. Analysis of data obtained from real-time PCR showed that EGCG at sub-MIC level (15.6μg/ml) significantly suppressed the gtf B, C, D genes of S. mutans UA159 compared with the non-treated control (p<0.05). ConclusionsThese findings suggest that EGCG may represent a novel, natural anti-plaque agent that inhibits the specific genes associated with bacterial biofilm formation without necessarily affecting the growth of oral bacteria.

Highlights

Dental caries is one of the most prevalent and costly oral infectious diseases throughout the world [1]
These findings suggest that Epigallocatechin gallate (EGCG) may represent a novel, natural anti-plaque agent that inhibits the specific genes associated with bacterial biofilm formation without necessarily affecting the growth of oral bacteria
EGCG at 31.25 μg/ml inhibited the area of cell coverage of S. mutans UA159 cells by 79.57% at 1 h, 98.33% at 2 h, and 91.78% at 4h compared with the non-treated control (Figure 1B)

Summary

Introduction

Dental caries is one of the most prevalent and costly oral infectious diseases throughout the world [1]. The EPS, especially water-insoluble glucans, mediate the initial adherence of S. mutans and other oral bacteria on tooth surfaces and facilitate the formation of mature dental plaque biofilm [8,9,10]. A recent study has shown that deletion of gtfB and gtfC genes in S. mutans resulted in diminished biofilm formation with minimal accumulation of bacteria and polysaccharides in vitro [10]. This suggested that suppression of gtf genes may represent an alternative approach to disrupting biofilm formation

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