Exopolysaccharides Produced by Streptococcus mutans Glucosyltransferases Modulate the Establishment of Microcolonies within Multispecies Biofilms
Exopolysaccharides Produced by Streptococcus mutans Glucosyltransferases Modulate the Establishment of Microcolonies within Multispecies Biofilms
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DOI：
10.1128/jb.01649-09
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发表时间：
2010-06-01
影响因子：
3.2
通讯作者：
Jeon, J. G.
中科院分区：
文献类型：
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作者：
Koo, H.;Xiao, J.;Jeon, J. G.
变形链球菌是牙体生物膜中胞外多糖（EPS）基质形成的关键因素。胞外多糖主要是由链球菌葡糖基转移酶（Gtfs）合成的葡聚糖，其提供促进微生物在牙齿表面上积累并进一步建立致病生物膜的结合位点。本研究探讨了（i）S.变形链球菌Gtfs在生物膜中EPS基质和小菌落形成中的作用，（ii）胞外多糖对小菌落形成的影响，以及（iii）S.使用一种新的荧光标记技术，在体外多物种生物膜中的变形杆菌。我们的数据表明，S。在唾液包被的羟基磷灰石表面上形成小菌落的gtfB基因或gtfB和gtfC基因缺陷的变形菌株被显著破坏。然而，为了最大限度地减少EPS基质和生物膜形成，需要删除gtfB（与不溶性葡聚糖合成相关）和gtfC（与不溶性和可溶性葡聚糖合成相关）。S.在口腔链球菌（Streptococcus oralis）和内氏放线菌（Actinomycesnaeslundii）的存在下，用蔗糖生长的变形菌稳定地形成胞外多糖，这允许细菌细胞的初始聚集并进一步发育成高度结构化的小菌落。同时，S。变形菌成为成熟生物膜中的主要种类。在多物种生物膜中葡萄糖的存在下，既不形成EPS基质也不形成小菌落。我们的数据表明，GtfB和GtfC是建立EPS基质所必需的，但GtfB似乎是由S.这些Gtf介导的过程可能会增强S.牙齿表面生物膜中的多物种环境中的变形菌。
Streptococcus mutans is a key contributor to the formation of the extracellular polysaccharide (EPS) matrix in dental biofilms. The exopolysaccharides, which are mostly glucans synthesized by streptococcal glucosyltransferases (Gtfs), provide binding sites that promote accumulation of microorganisms on the tooth surface and further establishment of pathogenic biofilms. This study explored (i) the role of S. mutans Gtfs in the development of the EPS matrix and microcolonies in biofilms, (ii) the influence of exopolysaccharides on formation of microcolonies, and (iii) establishment of S. mutans in a multispecies biofilm in vitro using a novel fluorescence labeling technique. Our data show that the ability of S. mutans strains defective in the gtfB gene or the gtfB and gtfC genes to form microcolonies on saliva-coated hydroxyapatite surfaces was markedly disrupted. However, deletion of both gtfB (associated with insoluble glucan synthesis) and gtfC (associated with insoluble and soluble glucan synthesis) is required for the maximum reduction in EPS matrix and biofilm formation. S. mutans grown with sucrose in the presence of Streptococcus oralis and Actinomyces naeslundii steadily formed exopolysaccharides, which allowed the initial clustering of bacterial cells and further development into highly structured microcolonies. Concomitantly, S. mutans became the major species in the mature biofilm. Neither the EPS matrix nor microcolonies were formed in the presence of glucose in the multispecies biofilm. Our data show that GtfB and GtfC are essential for establishment of the EPS matrix, but GtfB appears to be responsible for formation of microcolonies by S. mutans; these Gtf-mediated processes may enhance the competitiveness of S. mutans in the multispecies environment in biofilms on tooth surfaces.