茶多酚对变异链球菌-白色念珠菌双菌种生物膜抑制作用的体外研究OA

Based on the broad-spectrum antibacterial activity of tea polyphenols(TP),it was hypothesized that TP could suppress the formation of Streptococcus mutans-Candida albicans dual-species biofilms.Preliminary in vitro validation was conducted.The minimum inhibitory concentration(MIC)against the mixed biofilms was determined by two-fold serial dilution.Planktonic growth kinetics were monitored by optical-density curves.The MTT colorimetric assay,crystal violet staining,and colony-forming unit were used to determine biofilm metabolic activity,biomass,viable cell number,and adhesion strength,respectively.The expression of virulence-related genes in the biofilms of the two species was analyzed by real-time fluorescent quantitative PCR.TP exhibited a MIC of 2.0 mg·mL-1 against the S.mutans-C.albicans dual-species consortium and inhibited planktonic growth in a concentration-dependent manner.TP significantly reduced biofilm metabolic activity,biomass,and viable cell count;At concentrations of 0.5,1.0,and 2.0 mg·mL-1,adhesion rates dropped to approximately 60%,20%,and 10%,respectively.The pH of the 24-hour culture supernatant in the TP-treated groups was markedly higher than that of the control and increased with concentration.Mechanistically,TP of 2.0 mg·mL-1 downregulated key virulence gene expression in both species(gtfB,gtfD,gbpA,ftf,glgC in S.mutans and als1,hwp1,ras1 in C.albicans).These results provide initial evidence that TP can disrupt and inhibit mixed S.mutans-C.albicans biofilms in vitro,indicating its potential as a natural agent for modulating oral microecological dysbiosis.