Toutain Christine M, Caizza Nicky C, Zegans Michael E, O'Toole George A
Department of Microbiology and Immunology, Rm 505 Vail Building, N. College St., Dartmouth Medical School, Hanover, NH 03755, USA.
Res Microbiol. 2007 Jun;158(5):471-7. doi: 10.1016/j.resmic.2007.04.001. Epub 2007 Apr 21.
While Pseudomonas aeruginosa has only a single flagellum, its genome encodes two flagellar stators, called MotAB and MotCD. Here we report that despite no apparent alterations in swimming motility, mutations in either the MotAB or the MotCD stator render the strains defective for biofilm formation in both static and flow cell systems. Our data suggest distinct roles for the stators in early biofilm formation, with both the MotAB and MotCD stators playing a role in initial polar attachment of the bacterial cell to the surface (reversible attachment) and the MotAB stator also participating in the downstream adherence event of irreversible attachment. We also show that the initial polar attachment of P. aeruginosa to two different abiotic surfaces occurs largely at the flagellated end of the cell, a finding that should help develop models for early attachment events. Interestingly, in flowing conditions, a mutation in either stator alone revealed a more severe biofilm defect than mutating both stators or mutating the flagellum. Our data suggest that defects in biofilm formation observed for the stator mutants may be in part due to impacting flagellar reversal rates.
虽然铜绿假单胞菌只有一根鞭毛，但其基因组编码两种鞭毛定子，称为MotAB和MotCD。我们在此报告，尽管游动能力没有明显改变，但MotAB或MotCD定子中的突变都会使菌株在静态和流动细胞系统中形成生物膜的能力出现缺陷。我们的数据表明定子在早期生物膜形成中具有不同的作用，MotAB和MotCD定子都在细菌细胞与表面的初始极性附着（可逆附着）中发挥作用，并且MotAB定子还参与不可逆附着的下游黏附事件。我们还表明，铜绿假单胞菌在两种不同非生物表面上的初始极性附着主要发生在细胞的鞭毛端，这一发现应有助于建立早期附着事件的模型。有趣的是，在流动条件下，单独一个定子发生突变所显示的生物膜缺陷比两个定子都发生突变或鞭毛发生突变更为严重。我们的数据表明，定子突变体中观察到的生物膜形成缺陷可能部分归因于对鞭毛反转速率的影响。
