Targets for hydrogen-peroxide-induced damage to suspension and biofilm cells of Streptococcus mutans
Targets for hydrogen-peroxide-induced damage to suspension and biofilm cells of Streptococcus mutans
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DOI：
10.1139/w08-078
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发表时间：
2008-10-01
影响因子：
2.8
通讯作者：
Marquis, Robert E.
中科院分区：
文献类型：
--
作者：
Baldeck, Jeremiah D.;Marquis, Robert E.
过氧化氢(H(2)O(2))被认为是口腔细菌氧化应激的主要内源性来源，也被广泛应用于口腔护理产品中。我们的研究目的是确定H(2O)O(2)对悬浮液和单种生物膜中变形链球菌细胞损伤的特异性靶点，并区分过氧化氢的抑菌和杀菌作用。变形链球菌在悬浮培养和补料分批生物膜中生长，以评估活力、糖酵解和蛋白质合成对H(2)O(2)损伤的相对敏感性。研究发现，生物膜细胞对过氧化氢的敏感性与悬浮液中的细胞基本相同。低浓度的H(2)O(2)对糖酵解有很强的抑制作用，主要是抑菌作用。糖酵解抑制作用最敏感的靶点是3-磷酸甘油醛脱氢酶，作用15min，悬浮细胞的IC(50)(50%抑制浓度)约为2.2amol/L，生物膜的IC(50)约为2.3amol/L。磷酸烯醇式丙酮酸：葡萄糖磷酸转移酶途径不太敏感，IC(50)约为10 mmol/L，在过氧化氢的抑菌浓度下，醛缩酶不受抑制。对于悬浮液和生物膜，酸化在一定程度上降低了过氧化氢的敏感性，而升高的温度则增强了敏感性。当H(2)O(2)的浓度高于30 mm o l/L时，H(2)O(2)对变形链球菌主要是杀菌作用，而不是致突变作用。杀菌损伤的主要目标是蛋白质合成，从而使细胞无法修复或替换氧化损伤的蛋白质。
Hydrogen peroxide (H(2)O(2)) is considered a major endogenous source of oxidative stress to oral bacteria and also is widely used in oral care products. Our study objectives were to identify specific targets for H(2)O(2)-induced damage to cells of Streptococcus mutans in suspensions and monospecies biofilms and to differentiate bacteriostatic and bactericidal actions of the peroxide. Streptococcus mutans was grown in suspension cultures and fed-batch biofilms for assessing relative sensitivities of viability, glycolysis, and protein synthesis to H(2)O(2) damage. Biofilm cells were found to have essentially the same peroxide sensitivity as cells in suspensions. H(2)O(2) at low concentrations of about 16.3 mmol/L was highly inhibitory for glycolysis and mainly bacteriostatic. The most sensitive target detected for glycolytic inhibition was glyceraldehyde-3-phosphate dehydrogenase with IC(50) (50% inhibitory concentration) values of ca. 2.2ammol/L for suspension cells and 2.3 mmol/L for biofilms with 15 min treatments. The phosphoenolpyruvate:glucose phosphotransferase pathway was less sensitive with an IC(50) of ca. 10 mmol/L. Aldolase was not inhibited at bacteriostatic concentrations of the peroxide. For suspensions and biofilms, acidification somewhat diminished peroxide sensitivity, while increased temperature enhanced sensitivity. At concentrations above about 30 mmol/L, H(2)O(2) became mainly bactericidal but not mutagenic for S. mutans. A major target for bactericidal damage was protein synthesis, thus rendering cells incapable of repairing or replacing oxidatively damaged proteins.