Novel Bacterial Diversity and Fragmented eDNA Identified in Hyperbiofilm-Forming Pseudomonas aeruginosa Rugose Small Colony Variant
Novel Bacterial Diversity and Fragmented eDNA Identified in Hyperbiofilm-Forming Pseudomonas aeruginosa Rugose Small Colony Variant
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DOI：
10.1016/j.isci.2020.100827
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发表时间：
2020-02-21
期刊：
影响因子：
5.8
通讯作者：
Sen, Chandan K.
中科院分区：
文献类型：
--
作者：
Deng, Binbin;Ghatak, Subhadip;Sen, Chandan K.
铜绿假单胞菌生物膜代表了对卫生保健的主要威胁。从慢性感染中分离的铜绿假单胞菌的皱纹小菌落变体（RSCV）显示出超生物膜表型。RSCV生物膜对抗生素和宿主防御具有高度抗性。这项工作表明，RSCV生物膜聚集体由两个不同的细菌亚群组成，这两个亚群独特地组织起来，显示出截然不同的生理特征。与PAO 1相比，RSCV PAO 1 Delta wspF生物膜的胞外聚合物具有独特的超微结构特征。与PAO 1不同，PAO 1 Delta wspF从活细胞释放片段化的细胞外DNA（eDNA）。因此释放的片段化eDNA负责PAO 1 Delta wspF生物膜对DNaseI破坏的抗性。当添加到PAO 1中时，这种片段化的eDNA增强了生物膜的形成。PAO 1 Delta wspF生物膜的破坏是通过DNA-蛋白质相互作用的抑制剂--aurine tricarboxylic acid来实现的。这项工作提供了关键的新的见解，对比的结构和功能特征的超生物膜形成的临床细菌变异相对于自己的野生型菌株。
Pseudomonas aeruginosa biofilms represent a major threat to health care. Rugose small colony variants (RSCV) of P. aeruginosa, isolated from chronic infections, display hyperbiofilm phenotype. RSCV biofilms are highly resistant to antibiotics and host defenses. This work shows that RSCV biofilm aggregates consist of two distinct bacterial subpopulations that are uniquely organized displaying contrasting physiological characteristics. Compared with that of PAO1, the extracellular polymeric substance of RSCV PAO1 Delta wspF biofilms presented unique ultrastructural characteristics. Unlike PAO1, PAO1 Delta wspF released fragmented extracellular DNA (eDNA) from live cells. Fragmented eDNA, thus released, was responsible for resistance of PAO1 Delta wspF biofilm to disruption by DNaseI. When added to PAO1, such fragmented eDNA enhanced biofilm formation. Disruption of PAO1 Delta wspF biofilm was achieved by aurine tricarboxylic acid, an inhibitor of DNA-protein interaction. This work provides critical novel insights into the contrasting structural and functional characteristics of a hyperbiofilm-forming clinical bacterial variant relative to its own wild-type strain.