Regulation of Acinetobacter baumannii biofilm formation.
Regulation of Acinetobacter baumannii biofilm formation.
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DOI：
10.2217/fmb.09.5
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发表时间：
2009-04
影响因子：
3.1
通讯作者：
Actis LA
中科院分区：
文献类型：
--
作者：
Gaddy JA;Actis LA
鲍曼不动杆菌是一种革兰氏阴性机会性医院病原体。尽管存在干燥、营养缺乏和抗菌治疗等不利条件，这种微生物仍能在医院环境中生存。据推测，它在这些环境中持续存在的能力及其毒力是其形成生物膜的能力的结果。鲍曼不动杆菌在非生物表面（例如聚苯乙烯和玻璃）以及生物表面（例如上皮细胞和真菌丝）上形成生物膜。 Bap 表面粘附蛋白的菌毛组装和产生在最初附着于非生物表面后的生物膜启动和成熟中发挥着作用。此外，一些临床分离株的粘附和生物膜表型似乎与广谱抗生素耐药性的存在有关。这些生物膜的形成和发展的调节与该细菌赖以生存的表面以及参与该程序化多步骤过程的细胞成分一样多种多样。与生物膜形成相关的调节过程包括感测细菌细胞密度、不同营养物质的存在以及细菌细胞可用的游离阳离子的浓度。其中一些细胞外信号可能会被 BfmRS 等双组分调节系统感知。这种转录调节系统激活引导分子伴侣组装系统的表达，该组装系统负责产生菌毛，这是细胞附着和聚苯乙烯表面生物膜形成所需的。然而，当细胞在化学成分确定的培养基中培养时，非生物表面上的生物膜形成不需要这样的系统。有趣的是，BfmRS 系统还可以控制特定培养条件下的细胞形态。
Acinetobacter baumannii is a Gram-negative opportunistic nosocomial pathogen. This microorganism survives in hospital environments despite unfavorable conditions such as desiccation, nutrient starvation and antimicrobial treatments. It is hypothesized that its ability to persist in these environments, as well as its virulence, is a result of its capacity to form biofilms. A. baumannii forms biofilms on abiotic surfaces such as polystyrene and glass as well as biotic surfaces such as epithelial cells and fungal filaments. Pili assembly and production of the Bap surface-adhesion protein play a role in biofilm initiation and maturation after initial attachment to abiotic surfaces. Furthermore, the adhesion and biofilm phenotypes of some clinical isolates seem to be related to the presence of broad-spectrum antibiotic resistance. The regulation of the formation and development of these biofilms is as diverse as the surfaces on which this bacterium persists and as the cellular components that participate in this programmed multistep process. The regulatory processes associated with biofilm formation include sensing of bacterial cell density, the presence of different nutrients and the concentration of free cations available to bacterial cells. Some of these extracellular signals may be sensed by two-component regulatory systems such as BfmRS. This transcriptional regulatory system activates the expression of the usher-chaperone assembly system responsible for the production of pili, needed for cell attachment and biofilm formation on polystyrene surfaces. However, such a system is not required for biofilm formation on abiotic surfaces when cells are cultured in chemically defined media. Interestingly, the BfmRS system also controls cell morphology under particular culture conditions.