Surface tension gradient control of bacterial swarming in colonies of Pseudomonas aeruginosa
Surface tension gradient control of bacterial swarming in colonies of Pseudomonas aeruginosa
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DOI：
10.1039/c1sm06002c
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Vermant, J.
中科院分区：
文献类型：
--
作者：
Fauvart, M.;Phillips, P.;Vermant, J.
细菌集群是细菌在营养丰富的环境和宿主组织中定植的最有效的方法之一。已经提出了几种机制来解释这一现象和与之相关的复杂的宏观模式的形成，但到目前为止还没有提出确凿的证据来确定控制蜂群的因素。反之亦然，人们对如何控制蜂拥而至知之甚少。在这里，通过使用一系列互补的遗传和物理化学实验和一个简单的数学分析，我们展示了细菌聚集是如何由表面张力驱动的流动引起的。对条件致病菌铜绿假单胞菌进行了研究，因为这类细菌对控制和阻止蜂群是相关的。此外，铜绿假单胞菌分泌强大的表面活性成分，作为其群体感应系统的一部分。我们的结果表明，表面张力梯度控制甚至可以是驱动蜂拥而至的主要机制。它可以定量预测，并有望在各种细菌系统中发挥作用。该模型揭示了泥浆润湿条件和物理性质的微妙依赖关系。根据这些依赖关系，可以制定策略，通过简单的物理化学手段在特定条件下阻止蜂群涌入。
Bacterial swarming is one of the most efficient methods by which bacteria colonize nutrient-rich environments and host tissues. Several mechanisms have been proposed to explain the phenomenon and the associated intricate macroscopic pattern formation, but so far no conclusive evidence has been presented that identifies the factors that control swarming. Vice versa, little is known about how swarming can be controlled. Here, by using a series of complementary genetic and physicochemical experiments and a simple mathematical analysis, we show how the bacterial swarming can be caused by a surface tension driven flow. The opportunistic pathogen, Pseudomonas aeruginosa, is studied, as it is relevant for such bacteria to control and arrest swarming. Moreover, P. aeruginosa bacteria secrete strong surface active components as part of their quorum sensing system. Our results demonstrate that surface tension gradient control can even be the dominant mechanism that drives swarming. It can be quantitatively predicted and can be expected to play a role in a wide variety of bacterial systems. The modeling reveals subtle dependencies on both the wetting conditions and the physical properties of the slime. Based on these dependencies, strategies can be devised to arrest swarming under certain conditions by simple physicochemical means.