ULTRASONIC ENHANCEMENT OF ANTIBIOTIC ACTION ON BIOFILMS

植入的医疗设备有时会被感染，导致患者 痛苦和额外的手术以移除或替换 设备。植入物相关感染通常可以通过以下方法控制 抗生素治疗，但感染很少能完全治愈 被淘汰了。一旦停止抗生素治疗，感染 回归。感染性生物通常会分泌一种多糖粘液。 这似乎可以保护细菌免受抗生素治疗和 身体的防御机制。有几个假设是关于 感染对抗生素治疗的顽固性，其中大部分 胞外多糖在减少抗生素转运中的作用 或营养物质给细菌。 这项拟议的研究集中在消除细菌感染上。 利用高频压力波(超声波)工作的植入装置 与抗生素协同杀灭种植体上的细菌生物膜 设备。我们的初步结果表明，超声波可以增强 将抗生素输送到生物膜内的细胞，并可以增强 抗生素对固着细菌和浮游细菌的作用。为 例如，初步结果显示同时应用庆大霉素 2.25 MHz超声波对铜绿假单胞菌生物被膜的抑制作用 生物膜中的活细胞增加了3个数量级，67千赫 超声波通过以下途径降低固着和浮游铜绿假单胞菌的活力 近3个数量级。同样水平的超声波刺激 在没有抗生素存在的情况下对生存能力没有影响。其效果是 此外，还观察到了伊文氏杆菌和粪链球菌的具体目的 建议旨在扩大超声波和 抗生素，以增加对固体表面生物膜的杀灭，以及 研究其潜在的物理和化学机制。 1.1该项目将使细菌生物膜暴露于抗生素和 超声波确定细菌是否被杀死超过了完成的程度 仅靠抗生素。铜绿假单胞菌、粪链球菌和E. 线圈将在聚乙烯、聚亚安酯、硅橡胶和 玻璃表面。 1.2我们已经在杀灭P。 铜绿假单胞菌和大肠埃希氏菌对庆大霉素2.25 MHz和 67千赫的超声波。我们将尝试通过探索其他方法来优化杀戮 频率高达10 MHz，各种波形，功率密度，以及使用 另一种抗生素。 1.3我们将确定超声波在多大程度上促进运输 通过使用ESR自旋标记抗生素将抗生素注入细菌 超声波作用下细菌摄取动力学的测定 刺激。这将证明膜的运输是否 对超声波感到不安。 1.4我们将确定超声波在多大程度上促进运输 通过测量超声波对运输的影响，在细菌生物膜内 抗生素、氧气和其他分子通过生物膜。

Implanted medical devices sometimes become infected, resulting in patient suffering and additional surgery for removal or replacement of the device. Implant related infections can usually be controlled with antibiotic therapy, but the infection can rarely be completely eliminated. Once the antibiotic therapy is stopped, the infection returns. The infectious organisms usually exude a polysaccharide slime that appears to protect the bacteria from antibiotic therapy and from the body's defense mechanisms. There are several hypotheses concerning the recalcitrance of the infection toward antibiotic therapy, most of which implicate the exopolysaccharide in reducing the transport of antibiotics or nutrients to the bacteria. The proposed research is centered on eliminating bacterial infections on implant devices using high frequency pressure waves (ultrasound) to work synergistically with antibiotics to kill bacterial biofilms on implant devices. Our preliminary results indicate that ultrasound can enhance transport of antibiotic to cells within the biofilm, and can enhance the action of antibiotics against both sessile and planktonic bacteria. For example, preliminary results show simultaneous application of gentamicin and 2.25 MHz ultrasound to P. aeruginosa biofilms reduces the number of viable cells in the biofilm by 3 orders of magnitude, and that 67 kHz ultrasound reduces viability of sessile and planktonic P. aeruginosa by nearly 3 orders of magnitude. This same level of ultrasonic stimulation has no effect on viability when no antibiotic is present. The effect is also observed with E. coil, and S. fecaelis, The specific aims of this proposal are designed to expand this synergistic effect of ultrasound and antibiotics to increase the killing of biofilms on solid surfaces, and to investigate the underlying physical and chemical mechanisms. 1.1 The project will expose a bacterial biofilm to antibiotics and ultrasound to determine if bacteria are killed beyond that accomplished by the antibiotics alone. Biofilms of P. aeruginosa, S. fecaelis, and E. coil will be tested on polyethylene, polyurethane, silicone rubber, and glass surfaces. 1.2 We have already demonstrated synergistic effects in killing P. aeruginosa and E. coli with gentamicin in combination with 2.25 MHz and 67 kHz ultrasound. We will try to optimize the killing by exploring other frequencies up to 10 MHz, various waveforms, power densities, and the use of another antibiotic. 1.3 We will identify the extent to which ultrasound enhances transport of antibiotic into a bacterium by using ESR spin-labeled antibiotics to measure the kinetics of uptake into bacteria with and without ultrasonic stimulation. This will demonstrate whether the membrane transport is perturbed by ultrasound. 1.4 We will identify the extent to which ultrasound enhances transport within a bacterial biofilm by measuring ultrasonic effects upon transport of antibiotics, oxygen and other molecules through the biofilm.