Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Proc Natl Acad Sci U S A. 2013 Mar 12;110(11):4345-50. doi: 10.1073/pnas.1300321110. Epub 2013 Feb 11.
Biofilms are antibiotic-resistant, sessile bacterial communities that occupy most moist surfaces on Earth and cause chronic and medical device-associated infections. Despite their importance, basic information about biofilm dynamics in common ecological environments is lacking. Here, we demonstrate that flow through soil-like porous materials, industrial filters, and medical stents dramatically modifies the morphology of Pseudomonas aeruginosa biofilms to form 3D streamers, which, over time, bridge the spaces between obstacles and corners in nonuniform environments. We discovered that accumulation of surface-attached biofilm has little effect on flow through such environments, whereas biofilm streamers cause sudden and rapid clogging. We demonstrate that flow-induced shedding of extracellular matrix from surface-attached biofilms generates a sieve-like network that captures cells and other biomass, which add to the existing network, causing exponentially fast clogging independent of growth. These results suggest that biofilm streamers are ubiquitous in nature and strongly affect flow through porous materials in environmental, industrial, and medical systems.
生物膜是一种对抗生素具有耐药性的、不移动的细菌群落，它存在于地球上大多数潮湿的表面，会引起慢性和与医疗设备相关的感染。尽管它们很重要，但关于常见生态环境中生物膜动态的基本信息却很缺乏。在这里，我们证明了通过类似土壤的多孔材料、工业过滤器和医疗支架的流动，会极大地改变铜绿假单胞菌生物膜的形态，形成 3D 流丝，这些流丝会随着时间的推移，在不均匀的环境中架起障碍物和角落之间的桥梁。我们发现，表面附着的生物膜的积累对这种环境中的流动几乎没有影响，而生物膜流丝会导致突然而迅速的堵塞。我们证明，从表面附着的生物膜中流出的细胞外基质会产生一种类似筛网的网络，捕获细胞和其他生物质，这些生物质会添加到现有的网络中，导致堵塞速度呈指数级快速增加，而与生长无关。这些结果表明，生物膜流丝在自然界中普遍存在，并强烈影响环境、工业和医疗系统中多孔材料的流动。
