Inhibition of multidrug efflux as a strategy to prevent biofilm formation
Inhibition of multidrug efflux as a strategy to prevent biofilm formation
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DOI：
10.1093/jac/dkt420
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发表时间：
2014-03-01
影响因子：
5.2
通讯作者：
Webber, Mark A.
中科院分区：
文献类型：
--
作者：
Baugh, Stephanie;Phillips, Charlotte R.;Webber, Mark A.
目的：我们最近表明，沙门氏菌的任何多药物外排系统的失活都会导致形成有效生物膜的能力丧失。本研究的目的是确定多药外排与生物膜形成之间的联系机制，并确定抑制外排是否是一种可行的抗生物膜策略。方法：研究了鼠伤寒沙门氏菌中缺乏 AcrAB-TolC 系统成分的突变体聚集、产生生物膜基质成分和形成生物膜的能力。研究了通过外排泵输出生物膜相关底物的潜力，并测量了调节多药外排和生物膜基质成分产生的基因表达。评估了外排抑制剂羰基氰化物间氯苯腙、氯丙嗪和苯基精氨酸-β-萘酰胺在静态和流动条件下防止大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌形成生物膜的能力。 结果：缺乏的鼠伤寒沙门氏菌突变体 TolC 或 AcrB（但令人惊讶的是 AcrA 没有）形成生物膜的能力受到损害。这种缺陷与细胞疏水性、聚集能力或任何生物膜特异性因子的输出的变化无关。生物膜缺陷是由于 Curli 生物合成基因的转录抑制以及随之而来的 Curli 产生的抑制造成的。在静态和流动生物膜测定中，所有三种外排抑制剂均显着减少了生物膜的产生，尽管每种抑制剂的浓度不同，对每个物种的活性最强。结论：这项工作表明，外排泵的基因失活和化学抑制都会导致生物膜基质成分的转录抑制和生物膜形成的缺乏。因此，抑制外排是一种有前途的抗生物膜策略。
Objectives: We have recently shown that inactivation of any of the multidrug efflux systems of Salmonella results in loss of the ability to form a competent biofilm. The aim of this study was to determine the mechanism linking multidrug efflux and biofilm formation, and to determine whether inhibition of efflux is a viable antibiofilm strategy.Methods: Mutants lacking components of the AcrAB-TolC systemin Salmonella enterica serovar Typhimurium were investigated for their ability to aggregate, produce biofilm matrix components and form a biofilm. The potential for export of a biofilm-relevant substrate via efflux pumps was investigated and expression of genes that regulate multidrug efflux and production of biofilm matrix components was measured. The ability of efflux inhibitors carbonyl cyanide m-chlorophenylhydrazone, chlorpromazine and phenyl-arginine-beta-naphthylamide to prevent biofilm formation by Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus under static and flow conditions was assessed.Results: Mutants of Salmonella Typhimurium that lack TolC or AcrB, but surprisingly not AcrA, were compromised in their ability to form biofilms. This defect was not related to changes in cellular hydrophobicity, aggregative ability or export of any biofilm-specific factor. The biofilm defect resulted from transcriptional repression of curli biosynthesis genes and consequent inhibition of production of curli. All three efflux inhibitors significantly reduced biofilm production in both static and flow biofilm assays, although different concentrations of each inhibitor were most active against each species.Conclusions: This work shows that both genetic inactivation and chemical inhibition of efflux pumps results in transcriptional repression of biofilm matrix components and a lack of biofilm formation. Therefore, inhibition of efflux is a promising antibiofilm strategy.