Effects of iron on DNA release and biofilm development by Pseudomonas aeruginosa
Effects of iron on DNA release and biofilm development by Pseudomonas aeruginosa
复制标题
DOI：
10.1099/mic.0.2006/004911-0
复制
发表时间：
2007-05-01
期刊：
影响因子：
2.8
通讯作者：
Tolker-Nielsen, Tim
中科院分区：
文献类型：
--
作者：
Yang, Liang;Barken, Kim B.;Tolker-Nielsen, Tim
胞外DNA是铜绿假单胞菌生物膜的主要基质成分之一。它作为细胞间连接器发挥作用，并在生物膜的稳定中发挥作用。铜绿假单胞菌PAO 1生物膜中的DNA释放受las-rhl和pqs群体感应系统控制的证据先前已经提出。这篇论文提供了证据，铜绿假单胞菌PAO 1生物膜中的DNA释放也受到铁的调节。涉及在微量滴定盘中培养铜绿假单胞菌的实验表明，pqs表达、DNA释放和生物膜形成在具有低铁浓度（5 μ M FeClA）的培养基中有利，并且随着铁浓度的增加而降低。涉及铜绿假单胞菌在流动室系统中培养的实验表明，培养基中高水平的铁（1100 μ M FeCl 3）抑制DNA释放、结构生物膜的形成以及对抗菌化合物耐受性增加的亚群的形成。带有荧光报告基因的铜绿假单胞菌菌株的实验表明，pqs操纵子的表达在低铁条件（1 μ M FeCl 3）下在生物膜细胞的特定亚群中被诱导，但在高铁条件（100 μ M FeCl 3）下在生物膜细胞中被抑制。
Extracellular DNA is one of the major matrix components in Pseudomonas aeruginosa biofilms. It functions as an intercellular connector and plays a role in stabilization of the biofilms. Evidence that DNA release in P. aeruginosa PAO1 biofilms is controlled by the las-rhl and pqs quorum-sensing systems has been previously presented. This paper provides evidence that DNA release in P. aeruginosa PAO1 biofilms is also under iron regulation. Experiments involving cultivation of P. aeruginosa in microtitre trays suggested that pqs expression, DNA release and biofilm formation were favoured in media with low iron concentrations (5 mu M FeCIA and decreased with increasing iron concentrations. Experiments involving cultivation of P. aeruginosa in a flow-chamber system suggested that a high level of iron (1100 mu M FeCl3) in the medium suppressed DNA release, structural biofilm development, and the development of subpopulations with increased tolerance toward antimicrobial compounds. Experiments with P. aeruginosa strains harbouring fluorescent reporters suggested that expression of the pqs operon was induced in particular subpopulations of the biofilm cells under low-iron conditions (1 mu M FeCl3) but repressed in the biofilm cells under high-iron conditions (100 mu M FeCl3).