Imperial College London, Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, South Kensington Campus, Flowers Building, London SW7 2AZ, UK.
Environ Microbiol. 2011 Jul;13(7):1666-81. doi: 10.1111/j.1462-2920.2011.02495.x. Epub 2011 May 9.
Biofilm formation in P. aeruginosa is a highly regulated process that proceeds through a number of distinct stages. This development is controlled by a wide range of factors, of which two-component systems (TCSs) play a key role. In this review, we focus on some of the TCSs that regulate the switch from a motile to a sessile bacterial lifestyle, either via the production of extracellular appendages or by the production of exopolysaccharides. Extracellular appendages, such as flagella, type IV pili and Cup fimbriae are often involved in the initial attachment of bacteria to a surface. In P. aeruginosa, many of these surface structures are regulated by TCSs, and some systems regulate more than one type of appendage. Furthermore, the production of exopolysaccharides, such as Pel and Psl, is required for P. aeruginosa biofilm formation. The regulation of Pel and Psl is post-transcriptionally repressed by RsmA, the activity of which is controlled by a complex regulatory system involving several sensor kinases and accessory components. Furthermore, the Rsm system is a major control system that inversely regulates factors involved in motility and acute infection on one hand, and factors involved in biofilm formation and chronic infection on the other hand. Finally, a series of TCSs has recently been discovered that regulates biofilm development in a stage-specific manner. Taken together, these complex regulatory networks allow the bacterium to respond appropriately to diverse environmental stimuli, and increased knowledge of their mechanisms and signals could be of great importance in the design of novel antibacterial strategies.
铜绿假单胞菌生物膜的形成是一个高度调控的过程，经历了多个不同的阶段。这种发展受到多种因素的控制，其中双组分系统（TCS）起着关键作用。在这篇综述中，我们重点介绍了一些调节从运动到静止细菌生活方式转变的 TCS，这些调节方式要么通过产生细胞外附属物，要么通过产生胞外多糖来实现。细胞外附属物，如鞭毛、IV 型菌毛和 Cup 菌毛，通常参与细菌最初附着在表面上的过程。在铜绿假单胞菌中，许多这些表面结构都受到 TCS 的调节，并且一些系统调节不止一种类型的附属物。此外，多糖 Pel 和 Psl 的产生对于铜绿假单胞菌生物膜的形成是必需的。Pel 和 Psl 的产生受 RsmA 的转录后抑制，其活性受到涉及几个传感器激酶和辅助成分的复杂调节系统的控制。此外，Rsm 系统是一个主要的控制系统，一方面反向调节与运动性和急性感染有关的因子，另一方面调节与生物膜形成和慢性感染有关的因子。最后，最近发现了一系列 TCS，它们以特定的阶段特异性方式调节生物膜的发育。总之，这些复杂的调控网络使细菌能够对不同的环境刺激做出适当的反应，增加对它们的机制和信号的了解可能对设计新型抗菌策略具有重要意义。
