Microrheology of Bacterial Biofilms In Vitro: Staphylococcus aureus and Pseudomonas aeruginosa
Microrheology of Bacterial Biofilms In Vitro: Staphylococcus aureus and Pseudomonas aeruginosa
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DOI：
10.1021/la802442d
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发表时间：
2008-12-02
期刊：
影响因子：
3.9
通讯作者：
Waigh, T. A.
中科院分区：
文献类型：
--
作者：
Rogers, S. S.;van der Walle, C.;Waigh, T. A.
微米级细菌生物膜的流变学是了解粘附在固体表面的细菌的公共生命周期的重要一步，因为它测量它们如何相互粘附和解吸。粒子跟踪软件和成像硬件的改进使我们能够成功地采用粒子跟踪微流变学来测量基于金黄色葡萄球菌和铜绿假单胞菌的单种细菌生物膜。通过跟踪位移的细胞在一个范围内的时间尺度，我们分开的积极和热的贡献细胞运动。色葡萄金黄色葡萄球菌生物膜特别显示出与其它致密胶体悬浮液相同的幂律流变学。通过计算S.金黄色葡萄球菌生物膜，我们观察到它们在生长过程中变得不那么顺从，而在饥饿过程中变得更顺从。生物膜在微米尺度上是流变学不均匀的，这是由于对流动池表面的初始粘附强度、单个细菌的排列和较大尺度的结构（例如铜绿假单胞菌的絮凝物）。我们的S。金黄色葡萄球菌生物膜随着它们的成熟而变得均匀，这是高度的函数：细菌所经历的流变环境变得与它离流动池表面有多远无关。颗粒跟踪微流变学提供了生物膜“强度”的定量测量。因此，它可能被证明是有用的，在确定药物靶点和表征特定的分子变化对生物膜的微米级流变学的影响。
The rheology of bacterial biofilms at the micron scale is an important step to understanding the communal lifecycles of bacteria that adhere to solid surfaces, as it measures how they mutually adhere and desorb. Improvements in particle-tracking software and imaging hardware have allowed us to successfully employ particle-tracking microrheology to measuring single-species bacterial biofilms, based on Staphlococcus aureus and Pseudomonas aeruginosa. By tracking displacements of the cells at a range of timescales, we separate active and thermal contributions to the cell motion. The S. aureus biofilms in particular show power-law rheology, in common with other dense colloidal suspensions. By calculating the mean compliance of S. aureus biofilms, we observe them becoming less compliant during growth, and more compliant during starvation. The biofilms are rheologically inhomogeneous on the micron scale, as a result of the strength of initial adhesion to the flow cell surface, the arrangement of individual bacteria, and larger-scale structures such as floes of P. aeruginosa. Our S. aureus biofilms became homogeneous as a function of height as they matured: the theological environment experienced by a bacterium became independent of how far it lived from the flow cell surface. Particle-tracking microrheology provides a quantitative measure of the "strength" of a biofilm. It may therefore prove useful in identifying drug targets and characterizing the effect of specific molecular changes on the micron-scale rheology of biofilms.