赤藓糖醇对主要致龋链球菌及耐氟菌株生长和产酸的影响

Effects of erythritol on the growth and acid production of main cariogenic streptococci and their fluoride-resistant strains biofilm

目的通过赤藓糖醇对变形链球菌、远缘链球菌及其耐氟菌株混合菌生长和产酸影响的体外研究,为赤藓糖醇防龋作用的机理提供制论依据。方法采用最小抑菌浓度递增法对变形链球菌(S.mutans ATCC 25175,S.m)、远缘链球菌(S.sobrinus 6715,S.s)进行氟化钠体外诱导耐氟菌株(S.m-FR、S.s-FR),利用液体稀释法配制赤藓糖醇TSB液8个浓度,分别加入含有变形链球菌、远缘链球菌及其耐氟菌株的细菌混悬液48 h,用比浊法观察其对混合菌生长的影响,并用pH计测定培养前后上清液的△pH值。结果吸光度A值和△pH值实验前后与对照组相比最低浓度为12%时差异均有统计学意义(P<0.05),且随着浓度的升高A值和△pH值均下降。结论赤藓糖醇能抑制变形链球菌、远缘链球菌及耐氟菌株混合菌生长和产酸,并且随着浓度的升高抑制作用增强。

Objective To investigate the effects of erythritol on the growth and acid production of the mixed bacteria of S.mutans,S.sobrinus and their fluoride-resistant strains,and provide a theoretical basis of its cariostatic mechanism.Method S.mutans ATCC 25175（S.m）,S.sobrinus 6715（S.s） were induced with sodium fluoride at minimum inhibitory concentration to induce fluoride-resistant strains（S.m-FR,S.s-FR）.Liquid dilution method was adopted to get 8 different levels of Erythritol TSB solution,which were added with mixed bacterial suspensions containing S.mutans,S.sobrinus and their fluoride-resistant strains respectively for 48 hrs.Turbidimetry assay was used to study the inhibitory activity to the growth,and the △pH of supernatants were measured and calculated.Result The optical density A values and △pH of the experimental group,when the MIC of erythritol was 12%,showed significant difference from those of the control group（P0.05）.And with increasing concentration,both the A and △pH values decreased.Conclusion Erythritol has inhibitory effect on the growth and acid production of the mixed bacteria of S.mutans,S.sobrinus and their fluoride-resistant strains.And as the concentration increased the inhibition enhanced.