Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.
PLoS One. 2013 Aug 6;8(8):e68334. doi: 10.1371/journal.pone.0068334. Print 2013.
Biofilms are structured communities of bacteria that play a major role in the pathogenicity of bacteria and are the leading cause of antibiotic resistant bacterial infections on indwelling catheters and medical prosthetic devices. Failure to resolve these biofilm infections may necessitate the surgical removal of the prosthetic device which can be debilitating and costly. Recent studies have shown that application of surface acoustic waves to catheter surfaces can reduce the incidence of infections by a mechanism that has not yet been clarified. We report here the effects of surface acoustic waves (SAW) on the capacity of human neutrophils to eradicate S. epidermidis bacteria in a planktonic state and within biofilms. Utilizing a novel fibrin gel system that mimics a tissue-like environment, we show that SAW, at an intensity of 0.3 mW/cm(2), significantly enhances human neutrophil killing of S. epidermidis in a planktonic state and within biofilms by enhancing human neutrophil chemotaxis in response to chemoattractants. In addition, we show that the integrin CD18 plays a significant role in the killing enhancement observed in applying SAW. We propose from out data that this integrin may serve as mechanoreceptor for surface acoustic waves enhancing neutrophil chemotaxis and killing of bacteria.
生物膜是由细菌组成的结构化群落，在细菌的致病性中起着重要作用，也是留置导管和医疗假体设备中抗生素耐药细菌感染的主要原因。如果不能解决这些生物膜感染，可能需要手术切除假体，这可能会造成身体虚弱和昂贵的代价。最近的研究表明，应用表面声波（SAW）可以通过尚未阐明的机制降低感染的发生率。我们在这里报告了表面声波（SAW）对人类嗜中性粒细胞在浮游状态和生物膜中消灭表皮葡萄球菌细菌的能力的影响。利用模拟组织样环境的新型纤维蛋白凝胶系统，我们表明，在强度为 0.3 mW/cm(2) 的情况下，SAW 通过增强人类嗜中性粒细胞对趋化剂的趋化反应，显著增强了人类嗜中性粒细胞在浮游状态和生物膜中对表皮葡萄球菌的杀伤作用。此外，我们表明整合素 CD18 在应用 SAW 观察到的杀伤增强中起着重要作用。我们根据数据提出，这种整合素可能作为表面声波的机械感受器，增强嗜中性粒细胞的趋化性和细菌的杀伤作用。
