ULTRASONIC ENHANCEMENT OF ANTIBIOTIC ACTION ON BIOFILMS

超声波增强抗生素对生物膜的作用

• 批准号: 2445272
• 负责人: WILLIAM G PITT
• 金额: $ 17.86万
• 依托单位: BRIGHAM YOUNG UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2445272
• 关键词: Escherichia coli; Pseudomonas aeruginosa; Streptococcus pneumoniae; ampicillin; antibiotics; biological transport; disease /disorder prevention /control; drug interactions; electron spin resonance spectroscopy; gentamicins; glass; implant; infrared spectrometry; interferometry; lipid bilayer membrane; membrane permeability; monitoring device; oxygen transport; pharmacokinetics; polyethylenes; polyurethanes; silicone rubber; sound frequency; tissue /cell culture; ultrasound

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.

植入的医疗器械有时会受到感染，导致患者 痛苦和额外的手术来去除或替换 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 淘汰一旦停止抗生素治疗， 回报.感染性有机体通常渗出一种多糖粘液 它似乎可以保护细菌免受抗生素治疗， 身体的防御机制。有几个假设关于 感染对抗生素治疗的抵抗，其中大多数 表明胞外多糖减少了抗生素的转运 或营养物质。 拟议的研究集中在消除细菌感染上， 使用高频压力波（超声波）工作的植入装置 与抗生素协同杀灭植入物上细菌生物膜 装置.我们的初步结果表明，超声波可以增强 抗生素的运输到生物膜内的细胞，并可以增强 抗生素对固着菌和寄生菌的作用。为 例如，初步结果显示同时应用庆大霉素 和2.25 MHz超声对铜绿假单胞菌生物膜的作用减少了 生物膜中的活细胞增加了3个数量级，67 kHz 超声波通过以下方式降低固着和非固着铜绿假单胞菌的活力： 接近3个数量级。同样的超声波刺激 在没有抗生素存在时对生存力没有影响。效果 还观察到E. coil和S. fecaelis，这个的具体目的 这些建议旨在扩大超声波的这种协同效应， 抗生素，以增加对固体表面上的生物膜的杀灭，以及 来研究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， 超声波确定细菌是否被杀死 仅仅是抗生素。铜绿假单胞菌、S. fecaelis和E. 弹簧圈将在聚乙烯、聚氨酯、硅橡胶和 玻璃表面 1.2我们已经证明了协同效应在杀死P。 aeruginosa和E.大肠杆菌与庆大霉素联合2.25 MHz， 67 kHz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，功率密度和使用 另一种抗生素 1.3我们将确定超声波增强运输的程度 通过使用ESR自旋标记的抗生素， 在有和没有超声波的情况下测量细菌吸收的动力学 刺激.这将证明膜转运是否 受到超声波的干扰 1.4我们将确定超声波增强运输的程度 在细菌生物膜内通过测量超声波对运输的影响 抗生素、氧气和其他分子通过生物膜。