Flagellar and twitching motility are necessary for Pseudomonas aeruginosa biofilm development
Flagellar and twitching motility are necessary for Pseudomonas aeruginosa biofilm development
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DOI：
10.1046/j.1365-2958.1998.01062.x
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发表时间：
1998-10-01
影响因子：
3.6
通讯作者：
Kolter, R
中科院分区：
文献类型：
--
作者：
O'Toole, GA;Kolter, R
被称为生物膜的复杂细菌群落的形成始于浮游细胞与表面的相互作用，以响应适当的环境信号。我们报道了铜绿假单胞菌PA14突变体的分离和特性，该突变体在非生物表面聚氯乙烯（PVC）塑料上形成生物膜的起始缺陷。这些突变体被称为表面附着缺陷（sad）。分析了两类sad突变体：(i)鞭毛介导运动缺陷突变体和（ii）极地定位型IV型毛的生物发生缺陷突变体。我们用相差显微镜观察野生型形成的生物膜在8小时内的发育情况。野生型菌株首先在非生物表面形成单层细胞，随后出现分散在单层细胞中的微菌落。使用延时显微镜，我们提出的证据表明，微菌落形成的细胞聚集存在于单层。在野生型中观察到，合成IV型菌毛所需基因突变的菌株在PVC塑料上形成单层细胞。然而，与野生型菌株相比，IV型菌毛突变体在实验过程中没有形成微菌落，这表明这些结构在微菌落形成中起重要作用。即使在孵育8小时后，很少有非运动性菌株（携带flgK突变）的细胞附着在PVC上，这表明鞭毛和/或运动性在最初的细胞-表面相互作用中起作用。因此，这些突变体的表型使我们能够开始解剖导致生物膜形成的发育途径。
The formation of complex bacterial communities known as biofilms begins with the interaction of planktonic cells with a surface in response to appropriate environmental signals. We report the isolation and characterization of mutants of Pseudomonas aeruginosa PA14 defective in the initiation of biofilm formation on an abiotic surface, polyvinylchloride (PVC) plastic. These mutants are designated Surface attachment defective (sad). Two classes of sad mutants were analysed: (i) mutants defective in flagellar-mediated motility and (ii) mutants defective in biogenesis of the polar-localized type IV pili. We followed the development of the biofilm formed by the wild type over 8 h using phase-contrast microscopy. The wild-type strain first formed a monolayer of cells on the abiotic surface, followed by the appearance of microcolonies that were dispersed throughout the monolayer of cells. Using time-lapse microscopy, we present evidence that microcolonies form by aggregation of cells present in the monolayer. As observed with the wild type, strains with mutations in genes required for the synthesis of type IV pili formed a monolayer of cells on the PVC plastic. However, in contrast to the wild-type strain, the type IV pili mutants did not develop microcolonies over the course of the experiments, suggesting that these structures play an important role in microcolony formation. Very few cells of a non-motile strain (carrying a mutation in flgK) attached to PVC even after 8 h of incubation, suggesting a role for flagella and/or motility in the initial cell-to-surface interactions. The phenotype of these mutants thus allows us to initiate the dissection of the developmental pathway leading to biofilm formation.