Chelating agents exert distinct effects on biofilm formation in Staphylococcus aureus depending on strain background: role for clumping factor B
Chelating agents exert distinct effects on biofilm formation in Staphylococcus aureus depending on strain background: role for clumping factor B
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DOI：
10.1099/jmm.0.040758-0
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发表时间：
2012-08-01
影响因子：
3
通讯作者：
Jefferson, Kimberly K.
中科院分区：
文献类型：
--
作者：
Abraham, Nabil M.;Lamlertthon, Supaporn;Jefferson, Kimberly K.
金黄色葡萄球菌是导管感染的主要原因，生物膜的形成在发病机制中起着关键作用。金属离子螯合剂抑制细菌生物膜的形成和活力，使其成为导管封管溶液中有吸引力的候选成分。本研究的目的是进一步表征螯合剂对生物膜形成的影响。测试了钙螯合剂乙二醇四乙酸 (EGTA) 和柠檬酸三钠 (TSC) 对 30 个金黄色葡萄球菌菌株生物膜形成的影响。对亚抑制剂量的 EGTA 和 TSC 的反应根据菌株变异而显着变化。在一些菌株中，螯合剂阻止了生物膜的形成，在另一些菌株中则没有作用，而在另一些菌株中，它们实际上增强了生物膜的形成。使用两种相关菌株研究了这种表型变异的分子基础：Newman（其中生物膜形成受到螯合剂抑制）和10833（在螯合剂存在下形成强大的生物膜）。结果发现，在菌株 10833 中，编码表面粘附素聚集因子 B (clfB) 的基因的缺失完全消除了螯合剂诱导的生物膜形成。ClfB 在螯合剂中生物膜形成活性中的作用在其他菌株中得到了证实。结论是，生物膜形成能力根据菌株背景而显着变化，并且 ClfB 在 EGTA 和柠檬酸盐存在的情况下参与生物膜形成。这些结果表明，封管溶液中亚抑制剂量的螯合剂实际上可能会增强某些金黄色葡萄球菌菌株中生物膜的形成，并强调了适当使用这些试剂以一致地达到抑制剂量的重要性。
Staphylococcus aureus is a leading cause of catheter infections, and biofilm formation plays a key role in the pathogenesis. Metal ion chelators inhibit bacterial biofilm formation and viability, making them attractive candidates as components in catheter lock solutions. The goal of this study was to characterize further the effect of chelators on biofilm formation. The effect of the calcium chelators ethylene glycol tetraacetic acid (EGTA) and trisodium citrate (TSC) on biofilm formation by 30 S. aureus strains was tested. The response to subinhibitory doses of EGTA and TSC varied dramatically depending on strain variation. In some strains, the chelators prevented biofilm formation, in others they had no effect, and they actually enhanced biofilm formation in others. The molecular basis for this phenotypic variability was investigated using two related strains: Newman, in which biofilm formation was inhibited by chelators, and 10833, which formed strong biofilms in the presence of chelators. It was found that deletion of the gene encoding the surface adhesin clumping factor B (clfB) completely eliminated chelator-induced biofilm formation in strain 10833. The role of ClfB in biofilnn formation activity in chelators was confirmed in additional strains. It was concluded that biofilm-forming ability varies strikingly depending on strain background, and that ClfB is involved in biofilm formation in the presence EGTA and citrate. These results suggest that subinhibitory doses of chelating agents in catheter lock solutions may actually augment biofilnn formation in certain strains of S. aureus, and emphasize the importance of using these agents appropriately so that inhibitory doses are achieved consistently.