流动驱使表面附着的细菌向抽搐上游移动。
Flow directs surface-attached bacteria to twitch upstream.
机构信息
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, USA.
出版信息
Biophys J. 2012 Jul 3;103(1):146-51. doi: 10.1016/j.bpj.2012.05.045.
Bacteria inhabit a wide variety of environments in which fluid flow is present, including healthcare and food processing settings and the vasculature of animals and plants. The motility of bacteria on surfaces in the presence of flow has not been well characterized. Here we focus on Pseudomonas aeruginosa, an opportunistic human pathogen that thrives in flow conditions such as in catheters and respiratory tracts. We investigate the effects of flow on P. aeruginosa cells and describe a mechanism in which surface shear stress orients surface-attached P. aeruginosa cells along the flow direction, causing cells to migrate against the flow direction while pivoting in a zig-zag motion. This upstream movement is due to the retraction of type IV pili by the ATPase motors PilT and PilU and results from the effects of flow on the polar localization of type IV pili. This directed upstream motility could be beneficial in environments where flow is present, allowing bacteria to colonize environments that cannot be reached by other surface-attached bacteria.
细菌栖息在各种存在流体流动的环境中，包括医疗保健和食品加工场所以及动植物的脉管系统。在流动存在的情况下，细菌在表面的运动尚未得到很好的描述。在这里，我们关注铜绿假单胞菌，一种在流动条件下茁壮成长的机会性病原体，如导管和呼吸道。我们研究了流动对铜绿假单胞菌细胞的影响，并描述了一种机制，其中表面剪切应力使附着在表面上的铜绿假单胞菌细胞沿流动方向定向，导致细胞在旋转运动中沿流动方向迁移，同时在一个之字形运动中转动。这种上游运动是由于 ATP 酶 PilT 和 PilU 使 IV 型菌毛回缩所致，并且是流动对 IV 型菌毛的极性定位的影响所致。这种定向的上游运动在存在流动的环境中可能是有益的，因为它允许细菌定殖其他附着在表面上的细菌无法到达的环境。
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