Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan; Department of Stomatology, Taipei Veterans General Hospital, Taipei, Taiwan.
Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan.
Arch Oral Biol. 2018 Oct;94:69-77. doi: 10.1016/j.archoralbio.2018.06.019. Epub 2018 Jun 26.
Effects of tea catechin epigallocatechin-3-gallate (EGCG) against biofilm formation by Streptococcus mutans and probiotic Lactobacillus casei in Yakult (LcY) were examined.
Biofilms were formed by S. mutans alone (Sm) and co-culture of S. mutans and LcY (Sm + LcY) in the absence or presence of EGCG. The biomass of biofilms, which were sonicated or not, was measured by the crystal violet assay. Biofilm morphology was observed by scanning electron microscopy. Bacterial viability and extracellular polysaccharides were determined by SYTO9/propidium iodide and dextran-conjugated fluorescein staining, respectively, and confocal microscopy. Gene expression of glucosyltransferase was determined by quantitative polymerase chain reaction.
While 250 μg/ml EGCG significantly decreased the biomass and acid production of Sm biofilms, 500 μg/ml EGCG was required to inhibit Sm + LcY biofilm formation and acid production. EGCG decreased the amount of live bacteria present in both Sm and Sm + LcY biofilms. The level of dead bacteria in Sm + LcY biofilms was higher than in Sm biofilms when formed in the presence of 250 μg/ml EGCG. EGCG decreased levels of extracellular polysaccharides in Sm and Sm + LcY biofilms. The extent of biofilm removal by sonication was not different between Sm and Sm+LcY biofilms formed in the absence or presence of 62.5 or 125 μg/ml EGCG. The level of Sm gtfB and gtfD expression in Sm + LcY biofilms was higher than those in the Sm biofilms when formed in the presence of EGCG at 250 μg/ml.
The results indicated that LcY might interfere the inhibitory effects of EGCG against biofilm formation by S. mutans.
研究表没食子儿茶素没食子酸酯（EGCG）对变形链球菌和养乐多（LcY）共生乳酸杆菌生物膜形成的影响。
单独培养变形链球菌（Sm）和共培养变形链球菌和 LcY（Sm+LcY）形成生物膜，在有无 EGCG 的情况下，用结晶紫法测量超声处理或未处理的生物膜的生物量。通过扫描电子显微镜观察生物膜形态。通过 SYTO9/碘化丙啶和葡聚糖结合荧光素染色分别测定细菌活力和胞外多糖，并通过共聚焦显微镜观察。用定量聚合酶链反应测定葡糖基转移酶基因表达。
250μg/ml EGCG 显著降低 Sm 生物膜的生物量和产酸，但需要 500μg/ml EGCG 才能抑制 Sm+LcY 生物膜的形成和产酸。EGCG 减少了 Sm 和 Sm+LcY 生物膜中活细菌的数量。当在 250μg/ml EGCG 存在下形成时，Sm+LcY 生物膜中死细菌的水平高于 Sm 生物膜。EGCG 降低了 Sm 和 Sm+LcY 生物膜中的胞外多糖水平。在不存在或存在 62.5 或 125μg/ml EGCG 的情况下，超声处理对 Sm 和 Sm+LcY 生物膜的去除程度没有差异。当在 250μg/ml EGCG 存在下形成时，Sm+LcY 生物膜中 Sm gtfB 和 gtfD 的表达水平高于 Sm 生物膜。
结果表明，LcY 可能会干扰 EGCG 对变形链球菌生物膜形成的抑制作用。
