【作者】 徐蓉蓉；

【导师】 周学东；

【作者基本信息】 四川大学 ， 口腔临床医学， 2004， 硕士

【摘要】 本实验观察变形链球菌形成单菌种生物膜的结构以及胞外多糖在生物膜中的分布,比较变形链球菌在生物膜状态下合成水溶性、水不溶性胞外多糖与浮游状态下合成水溶性、水不溶性胞外多糖量的差异,并探讨差异的可能原因。 本实验是在玻璃片上培养变形链球菌,待其形成单菌种生物膜,用荧光染料BODIPY进行染色,激光共聚焦扫描显微镜观察其形成的生物膜结构。荧光染料Calcofluor标记生物膜中的胞外多糖,激光共聚焦扫描显微镜下观察生物膜中胞外多糖的分布情况。变形链球菌分别进行静置培养和摇动培养24小时,以得到生物膜状态和浮游状态下的变形链球菌,蒽酮法测定两种培养方式下细菌合成的水溶性胞外多糖和水不溶性胞外多糖的含量。延长培养时间到48小时,测定两种培养方式下细菌合成的水溶性胞外多糖和水不溶性胞外多糖的含量。 结果显示变形链球菌形成的单菌种生物膜由微菌落构成,有组织结构特点,形成团块条索状结构,其中有空隙分布,细菌所需的营养成份可能通过这些空隙到达。生物膜状态下与浮游状态下变形链球菌合成水溶性、水不溶性胞外多糖的量,随着培养基中蔗糖浓度的增加而增加。每种蔗糖浓度条件下,生物膜状态下变形链球菌合成胞外多糖均要多于浮游状态下的细菌,有显著性差异(P<0.05)。生物膜状态下与浮游状态下变形链球菌的数量和合成胞外多糖的量随着时间的增加而增加。生物膜状态下变形更多还原

【Abstract】 To elucidate the biofilm structure of Streptococcus mutans and the spatial distribution of exopolysaccharides in the biofilm. Compare the effect of different cultivation conditions (planktonic vs. attached) on the amount of exopolysaccharides produced by the Streptococcus mutans.The biofilm of Streptococcus mutans was prepared by allowing bacteria to grow on the surface of glass slide. Stained by BODIPY, a fluorescent stain, the biofilm structure was observed under the Confocal Laser Scanning Microscopy (CLSM).Marked with Calcofluor, another fluorescent dye, the exopolysaccharides produced by Streptococcus mutans were also visualized under CLSM.Anthrone Method was applied to measure the amount of soluble and insoluble exopolysaccharides produced by Streptococcus mutans cultivated at planktonic condition and attached condition.Streptococcus mutans can attach to glass surface and form the biofilms,which are composed of micro-colonies ,with channels acrossing it. Cells were embedded within the exopolysaccharides.They were sparse in the substratum area and surface layer but dense in the center. Adhensive Streptococcus mutans produced more exopolysaccharides than planktonic ones under varied sugar concentrations (P<0.05) .Based on the findings,adhensive Streptococcus mutans produces more exopolysaccharides, which plays an important role in the procession of biofilm formation.更多还原