【作者】 徐欣； 李继遥； 周学东； Christine D.Wu；

【Author】 Xin Xu,~(1,2) Jiyao Li,~1 Xue D.Zhou,~1 and Christine D.Wu~2(1.State Key Laboratory of Oral Diseases,Sichuan University,2.Department of Pediatric Dentistry,College of Dentistry, University of Illinois at Chicago,Chicago,IL,USA.)

【机构】 口腔疾病研究国家重点实验室(四川大学)； 美国伊利诺伊大学芝加哥分校牙学院儿童牙病学系；

【摘要】 目的:研究EGCg对变异链球菌gtf基因表达及生物膜形成的影响。方法:直接购买获得实验用EGCg经直接购买获得(纯度>95%,HPLC)。通过chamber slide生物膜形成模型研究不同生长培养基中,亚抑菌浓度EGCg对变异链球菌体外形成生物膜的动态影响。通过细菌凝集实验,研究EGCg在不同生长培养基中对变异链球菌细菌凝集的影响。通过Real-time PCR检测EGCg对变异链球菌gtfB,C,D基因表达的影响。结果:EGCg(7.8-31.25μg/m l)在化学限定培养基中对变异链球菌生物膜形成具有浓度依耐性抑制作用。EGCg(1 56.25-31 2.5μg/ml)在BHI培养基中对变异链球菌生物膜形成具有类似抑制作用,但在625μg/ml浓度下,对生物膜形成具有一定促进作用。这可能与该浓度下EGCg诱导变异链球菌细菌部分凝集(凝集率<50%)有关。Real-time PCR显示,EGCg在亚抑菌浓度下能显著抑制变异链球菌生物膜形成相关基因gtfB,C,D表达。结论:EGCg能在不影响细菌正常生长浓度下,通过抑制变异链球菌gtf基因表达,抑制其生物膜形成。更多还原

【Abstract】 Purpose:To investigate the biological effect of EGCg on biofilm formation of S.mutans.Methods:Epigallocatechin gallate from green tea(EGCg,95%HPLC) was commercially obtained.The effects of EGCg on the initial attachment of S.mutans UA159 cells grown in both chemically defined medium and BHI were monitored over 4 h using a chamber slide model.The cellular aggregation of S.mutans UA159 cells induced by varying concentrations of EGCg was also examined.The effects of sub-lethal levels of EGCg on the transcriptional expression of gtf B,C,D genes in S.mutans UA159 were quantified by real-time PCR.Results:EGCg exhibited dosage-dependent inhibition on the initial attachment of S.mutans UA159 cells in chemically defined medium.Although similar inhibition was observed in BHI(EGCg ranging from 156.25μg/ml to 312.5μg/ml),EGCg at 625μg/ml induced an increase in cells attachment,which may be attributed to the small percentage of cellular aggregation(<50%) induced by EGCg at this concentration. EGCg at sub-lethal levels also significantly suppressed the gtfB,C,D genes of S.mutans UA159 in both chemically defined medium and BHI(p < 0.05).Conclusion:EGCg is able to suppress gtf genes expression,thus inhibiting initial attachment and biofilm formation of S. mutans cells without necessarily suppressing the resident oral bacteria.更多还原