Razatos A, Ong Y L, Sharma M M, Georgiou G
Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA.
Proc Natl Acad Sci U S A. 1998 Sep 15;95(19):11059-64. doi: 10.1073/pnas.95.19.11059.
Bacterial adhesion and the subsequent formation of biofilm are major concerns in biotechnology and medicine. The initial step in bacterial adhesion is the interaction of cells with a surface, a process governed by long-range forces, primarily van der Waals and electrostatic interactions. The precise manner in which the force of interaction is affected by cell surface components and by the physiochemical properties of materials is not well understood. Here, we show that atomic force microscopy can be used to analyze the initial events in bacterial adhesion with unprecedented resolution. Interactions between the cantilever tip and confluent monolayers of isogenic strains of Escherichia coli mutants exhibiting subtle differences in cell surface composition were measured. It was shown that the adhesion force is affected by the length of core lipopolysaccharide molecules on the E. coli cell surface and by the production of the capsular polysaccharide, colanic acid. Furthermore, by modifying the atomic force microscope tip we developed a method for determining whether bacteria are attracted or repelled by virtually any biomaterial of interest. This information will be critical for the design of materials that are resistant to bacterial adhesion.
细菌黏附以及随后生物膜的形成是生物技术和医学领域的主要关注点。细菌黏附的第一步是细胞与表面的相互作用，这一过程受长程力支配，主要是范德华力和静电相互作用。细胞表面成分以及材料的物理化学性质如何精确影响相互作用力的方式尚不清楚。在此，我们表明原子力显微镜可用于以前所未有的分辨率分析细菌黏附的初始事件。测量了悬臂尖端与细胞表面组成存在细微差异的大肠杆菌突变体同基因菌株的汇合单层之间的相互作用。结果表明，黏附力受大肠杆菌细胞表面核心脂多糖分子的长度以及荚膜多糖（柯氏酸）产生的影响。此外，通过对原子力显微镜尖端进行修饰，我们开发了一种方法，用于确定细菌实际上是否被任何感兴趣的生物材料吸引或排斥。这些信息对于设计抗细菌黏附的材料至关重要。
