Infection and Immunity Research Group, School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, BT52 1SA Northern Ireland, UK.
BMC Microbiol. 2010 Feb 8;10:38. doi: 10.1186/1471-2180-10-38.
Pseudomonas aeruginosa is considered to grow in a biofilm in cystic fibrosis (CF) chronic lung infections. Bacterial cell motility is one of the main factors that have been connected with P. aeruginosa adherence to both biotic and abiotic surfaces. In this investigation, we employed molecular and microscopic methods to determine the presence or absence of motility in P. aeruginosa CF isolates, and statistically correlated this with their biofilm forming ability in vitro.
Our investigations revealed a wide diversity in the production, architecture and control of biofilm formation. Of 96 isolates, 49% possessed swimming motility, 27% twitching and 52% swarming motility, while 47% were non-motile. Microtitre plate assays for biofilm formation showed a range of biofilm formation ability from biofilm deficient phenotypes to those that formed very thick biofilms. A comparison of the motility and adherence properties of individual strains demonstrated that the presence of swimming and twitching motility positively affected biofilm biomass. Crucially, however, motility was not an absolute requirement for biofilm formation, as 30 non-motile isolates actually formed thick biofilms, and three motile isolates that had both flagella and type IV pili attached only weakly. In addition, CLSM analysis showed that biofilm-forming strains of P. aeruginosa were in fact capable of entrapping non-biofilm forming strains, such that these 'non-biofilm forming' cells could be observed as part of the mature biofilm architecture.
Clinical isolates that do not produce biofilms in the laboratory must have the ability to survive in the patient lung. We propose that a synergy exists between isolates in vivo, which allows "non biofilm-forming" isolates to be incorporated into the biofilm. Therefore, there is the potential for strains that are apparently non-biofilm forming in vitro to participate in biofilm-mediated pathogenesis in the CF lung.
铜绿假单胞菌被认为在囊性纤维化 (CF) 慢性肺部感染中生长在生物膜中。细菌细胞的运动性是与铜绿假单胞菌对生物和非生物表面的附着有关的主要因素之一。在这项研究中，我们采用分子和显微镜方法来确定 CF 分离株中是否存在运动性，并将其与体外生物膜形成能力进行统计学相关分析。
我们的研究揭示了生物膜形成的产生、结构和控制方面的广泛多样性。在 96 个分离株中，49%具有泳动性，27%具有滚动性，52%具有群集性，而 47%为非运动性。微量滴定板法用于生物膜形成的检测显示，生物膜形成能力的范围从生物膜缺乏表型到形成非常厚的生物膜。对单个菌株的运动性和附着特性的比较表明，泳动性和滚动性的存在对生物膜生物量有积极影响。然而，至关重要的是，运动性不是生物膜形成的绝对要求，因为 30 个非运动性分离株实际上形成了厚厚的生物膜，而三个具有鞭毛和 IV 型菌毛的运动性分离株仅附着得很弱。此外，CLSM 分析表明，实际上铜绿假单胞菌的生物膜形成菌株能够捕获非生物膜形成的菌株，使得这些“非生物膜形成”细胞可以作为成熟生物膜结构的一部分被观察到。
在实验室中不产生生物膜的临床分离株必须具有在患者肺部存活的能力。我们提出，体内分离株之间存在协同作用，允许“非生物膜形成”分离株被纳入生物膜。因此，体外表现出非生物膜形成的菌株有可能参与 CF 肺部的生物膜介导的发病机制。
