Inhibitory effects of theaflavin on planktonic and sessile bacterial cells of Streptococcus mutans in vitro

PURPOSE Inhibitory effects of theaflavin(TF) on planktonic and sessile bacterial cells of Streptococcus mutans were investigated in the present study. METHODS MIC and MBC of TF/EGCG/CHX on S. mutans UA159 were determined. Furthermore, biofilms were formed and treated with agents, then proliferative activity and viability of bacterial cells were detected. SPSS 22.0 software package was used for statistical analysis. RESULTS TF was found to inhibit planktonic cells of S. mutans UA159 with MIC of 500 μg/mL and MBC of 1 mg/mL. Moreover, bacterial cells of S. mutans UA159 in the biofilms treated with TF at concentrations higher than 2*MIC had lower proliferative activity and viability than those in control-treated biofilms. CONCLUSIONS TF efficiently suppressed proliferative activity and viability of S. mutans biofilms, which provided theoretical basis for clinic applications of TF.