Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.
Antimicrob Agents Chemother. 2013 Oct;57(10):4877-81. doi: 10.1128/AAC.01381-13. Epub 2013 Jul 22.
The ability of nitric oxide (NO) to induce biofilm dispersion has been well established. Here, we investigated the effect of nitroxides (sterically hindered nitric oxide analogues) on biofilm formation and swarming motility in Pseudomonas aeruginosa. A transposon mutant unable to produce nitric oxide endogenously (nirS) was deficient in swarming motility relative to the wild type and the complemented strain. Moreover, expression of the nirS gene was upregulated by 9.65-fold in wild-type swarming cells compared to planktonic cells. Wild-type swarming levels were substantially restored upon the exogenous addition of nitroxide containing compounds, a finding consistent with the hypothesis that NO is necessary for swarming motility. Here, we showed that nitroxides not only mimicked the dispersal activity of NO but also prevented biofilms from forming in flow cell chambers. In addition, a nirS transposon mutant was deficient in biofilm formation relative to the wild type and the complemented strain, thus implicating NO in the formation of biofilms. Intriguingly, despite its stand-alone action in inhibiting biofilm formation and promoting dispersal, a nitroxide partially restored the ability of a nirS mutant to form biofilms.
一氧化氮（NO）诱导生物膜分散的能力已得到充分证实。在这里，我们研究了氮氧化物（空间位阻的一氧化氮类似物）对铜绿假单胞菌生物膜形成和 swarm 运动的影响。与野生型和互补菌株相比，不能内源产生一氧化氮的转座子突变体在 swarm 运动方面存在缺陷。此外，与浮游细胞相比，野生型 swarm 细胞中 nirS 基因的表达水平上调了 9.65 倍。外源添加含氮氧化物的化合物可显著恢复野生型 swarm 水平，这一发现与 NO 是 swarm 运动所必需的假设一致。在这里，我们表明氮氧化物不仅模拟了 NO 的分散活性，而且还可以防止生物膜在流动细胞室中形成。此外，与野生型和互补菌株相比，nirS 转座子突变体在生物膜形成方面存在缺陷，因此表明 NO 参与了生物膜的形成。有趣的是，尽管氮氧化物在单独抑制生物膜形成和促进分散方面具有作用，但它部分恢复了 nirS 突变体形成生物膜的能力。
