Differential Lipopolysaccharide Core Capping Leads to Quantitative and Correlated Modifications of Mechanical and Structural Properties in Pseudomonas aeruginosa Biofilms
Differential Lipopolysaccharide Core Capping Leads to Quantitative and Correlated Modifications of Mechanical and Structural Properties in Pseudomonas aeruginosa Biofilms
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DOI：
10.1128/jb.00698-09
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发表时间：
2009-11-01
影响因子：
3.2
通讯作者：
Lam, Joseph S.
中科院分区：
文献类型：
--
作者：
Lau, Peter C. Y.;Lindhout, Theresa;Lam, Joseph S.
细菌生物膜是大多数微生物感染的原因，并对工业和地球化学过程产生深远影响。虽然许多研究记录了生物膜的表型分化和基因调控，但对其结构和机械特性的重要性却知之甚少。在这里，我们研究了铜绿假单胞菌中脂多糖（LPS）核心帽的变化如何通过在生物膜发育的早期阶段改变粘附性、内聚性和粘弹性特性来影响生物膜结构。使用微珠力光谱和原子力显微镜来表征铜绿假单胞菌生物膜与玻璃基质或细菌菌苔的相互作用。使用具有明确 LPS 特征的同基因 migA、wapR 和 rmlC 突变体，我们观察到与野生型菌株 PAO1 相比，这些菌株的细胞机械特性发生显着变化。具体来说，核心寡糖的截短将粘合力和内聚力增强了多达 10 倍，而瞬时弹性的变化与 O 抗原的存在相关。使用共焦激光扫描显微镜来量化生物膜结构随 LPS 核心封盖差异的变化，我们观察到纹理参数随粘附力或内聚力的倒数而变化，而面积和体积参数则与粘附力、内聚力或它们之间的平衡相关。总之，该报告首次证明 LPS 表达的变化导致可量化的细胞机械变化，这些变化与细菌生物膜的结构变化相关。因此，结构和功能特性之间的相互作用可能是细菌群落生存的重要贡献者。
Bacterial biofilms are responsible for the majority of all microbial infections and have profound impact on industrial and geochemical processes. While many studies documented phenotypic differentiation and gene regulation of biofilms, the importance of their structural and mechanical properties is poorly understood. Here we investigate how changes in lipopolysaccharide (LPS) core capping in Pseudomonas aeruginosa affect biofilm structure through modification of adhesive, cohesive, and viscoelastic properties at an early stage of biofilm development. Microbead force spectroscopy and atomic force microscopy were used to characterize P. aeruginosa biofilm interactions with either glass substrata or bacterial lawns. Using isogenic migA, wapR, and rmlC mutants with defined LPS characteristics, we observed significant changes in cell mechanical properties among these strains compared to wild-type strain PAO1. Specifically, truncation of core oligosaccharides enhanced both adhesive and cohesive forces by up to 10-fold, whereas changes in instantaneous elasticity were correlated with the presence of O antigen. Using confocal laser scanning microscopy to quantify biofilm structural changes with respect to differences in LPS core capping, we observed that textural parameters varied with adhesion or the inverse of cohesion, while areal and volumetric parameters were linked to adhesion, cohesion, or the balance between them. In conclusion, this report demonstrated for the first time that changes in LPS expression resulted in quantifiable cellular mechanical changes that were correlated with structural changes in bacterial biofilms. Thus, the interplay between architectural and functional properties may be an important contributor to bacterial community survival.