Introduction. Indwelling medical devices such as endotracheal tubes (ETTs), urinary catheters, vascular access devices, tracheostomies and feeding tubes are often associated with hospital-acquired infections. Bacterial biofilm formed on the ETTs in intubated patients is a significant risk factor associated with ventilator-associated pneumonia. Pseudomonas aeruginosa is one of the four frequently encountered bacteria responsible for causing pneumonia, and the biofilm formation on ETTs. However, understanding of biofilm formation on ETT and interventions to prevent biofilm remains lagging. The ability to sense and adapt to external cues contributes to their success. Thus, the biofilm formation is likely to be influenced by the two-component systems (TCSs) that are composed of a membrane-associated sensor kinase and an intracellular response regulator.Aim. This study aims to establish an in vitro method to analyse the P. aeruginosa biofilm formation on ETTs, and identify the TCSs that contribute to this process.Methodology. In total, 112 P. aeruginosa PA14 TCS mutants were tested for their ability to form biofilm on ETTs, their effect on quorum sensing (QS) and motility.Results. Out of 112 TCS mutants studied, 56 had altered biofilm biomass on ETTs. Although the biofilm formation on ETTs is QS-dependent, none of the 56 loci controlled quorum signal. Of these, 18 novel TCSs specific to ETT biofilm were identified, namely, AauS, AgtS, ColR, CopS, CprR, NasT, KdpD, ParS, PmrB, PprA, PvrS, RcsC, PA14_11120, PA14_32580, PA14_45880, PA14_49420, PA14_52240, PA14_70790. The set of 56 included the GacS network, TCS proteins involved in fimbriae synthesis, TCS proteins involved in antimicrobial peptide resistance, and surface-sensing. Additionally, several of the TCS-encoding genes involved in biofilm formation on ETTs were found to be linked to flagellum-dependent swimming motility.Conclusions. Our study established an in vitro method for studying P. aeruginosa biofilm formation on the ETT surfaces. We also identified novel ETT-specific TCSs that could serve as targets to prevent biofilm formation on indwelling devices frequently used in clinical settings.

中文翻译：

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气管内导管上的铜绿假单胞菌生物膜形成需要多个两组分系统。

介绍。诸如气管内插管（ETTs），导尿管，血管通路设备，气管切开术和饲管的留置医疗设备通常与医院获得性感染有关。插管患者的ETT上形成的细菌生物膜是与呼吸机相关性肺炎相关的重要危险因素。铜绿假单胞菌是导致肺炎和ETTs生物膜形成的四种常见细菌之一。但是，对ETT上生物膜形成的认识以及防止生物膜的干预措施仍然滞后。感知并适应外部提示的能力有助于他们的成功。从而，生物膜的形成可能会受到由膜相关传感器激酶和细胞内反应调节剂组成的两组分系统（TCS）的影响。这项研究旨在建立一种体外方法，以分析ETT上的铜绿假单胞菌生物膜形成，并鉴定有助于该过程的TCS。总共测试了112个铜绿假单胞菌PA14 TCS突变体在ETTs上形成生物膜的能力，它们对群体感应（QS）和运动性的影响。在研究的112个TCS突变体中，有56个改变了ETTs上的生物膜生物量。尽管ETTs上的生物膜形成是QS依赖性的，但56个基因座均未控制群体信号。其中，鉴定出了18种针对ETT生物膜的新型TCS，即AauS，AgtS，ColR，CopS，CprR，NasT，KdpD，ParS，PmrB，PprA，PvrS，RcsC，PA14_11120，PA14_32580，PA14_45880，PA14_49420，PA14_52240，PA14_70790。这套56个样本包括GacS网络，参与菌毛合成的TCS蛋白，参与抗微生物肽耐药性的TCS蛋白和表面传感。此外，发现一些与ETTs生物膜形成有关的TCS编码基因与鞭毛依赖性游泳运动有关。我们的研究建立了一种用于研究ETT表面铜绿假单胞菌生物膜形成的体外方法。我们还确定了新型ETT特异的TCS，它们可以用作目标，以防止在临床环境中经常使用的留置装置上形成生物膜。此外，发现一些与ETTs生物膜形成有关的TCS编码基因与鞭毛依赖性游泳运动有关。我们的研究建立了一种用于研究ETT表面铜绿假单胞菌生物膜形成的体外方法。我们还确定了新型ETT特异的TCS，它们可以用作目标，以防止在临床环境中经常使用的留置装置上形成生物膜。此外，发现与ETTs生物膜形成有关的几种TCS编码基因与鞭毛依赖的游泳运动有关。我们的研究建立了一种用于研究ETT表面铜绿假单胞菌生物膜形成的体外方法。我们还确定了新型ETT特异的TCS，它们可以用作目标，以防止在临床环境中经常使用的留置装置上形成生物膜。