Microbial infections on implanted medical devices are difficult to treat. Application of 70 kHz ultrasonic irradiation to gentamicin treatment greatly enhanced the action of the antibiotic in terms of reduced viable bacterial concentrations. Ultrasonic irradiation was carried out at various insonation intensities that were noninhibitory in the absence of antibiotic. Synergistic killing was observed to be a function of ultrasonic intensity. Greatest killing (approximately 5 log reduction in viable population) was realized at full intensity (4.5 W/cm2), and decreased with reductions in power density. At lowest intensity (10 mW/cm2), no significant acoustic enhanced killing was noted.
1. Gristina, A. G.1987. "Biomaterial-Centered Infection: Microbial Adhesion versus Tissue Integration,"Science, 237:1588-1595.
2.
2. Oga, M., Y. Sugioka, C. D. Hobgood, A. G. Gristina and Q. N. Myrvik. 1988. "Surgical Biomaterials and Differential Colonization by Staphylococcus epidermidis,"Biomaterials, 9:285-289.
3.
3. Jacques, M., T. J. Marrie and J. W. Costerton. 1987. "Microbial Colonization of Prosthetic Devices,"Microb. Ecol., 13:173-191.
4.
4. Costerton, J. W., A. Lewandowski, D. E. Caldwell, D. R. Korber and H. M. Lappin-Scott. 1995. "Microbial Biofilms,"Annu. Rev. Microbiol., 49:711-745.
5.
5. Anwar, H., J. L. Strap and J. W. Costerton. 1992. "Establishment of Aging Biofilms: Possible Mechanism of Bacterial Resistance to Antimicrobial Therapy,"Antimicrob. Agents and Chemother., 36:1347-1351.
6.
6. Costerton, J. W. and H. M. Lappin-Scott. 1989. "Behavior of Bacteria in Biofilms,"ASM News, 55:650-654.
7.
7. Costerton, J. W., K. J. Cheng, G. G. Geesey, T. I. Ladd, J. C. Nickel and M. Dasgupta. 1987. "Bacterial Biofilms in Nature and Disease,"Ann. Rev. Microbiol., 41:435-464.
8.
8. Wise, R.1990. "The Biofilm Glycocalyx as a Resistance Factor,"J. Antimicrobial Chemother., 26:1-6.
9.
9. Blenkinsopp, S. A., A. E. Khoury and J. W. Costerton. 1992. "Electrical Enhancement of Biocide Efficacy against Biofilms,"Appl. and Environ. Microb., 58:3770-3773.
10.
10. Khoury, A. E., K. Lam, B. Ellis and J. W. Costerton. 1992. "Prevention and Control of Bacterial Infections Associated with Medical Devices,"J. Am. Soc. Artif. Intern. Organs, 38:M174-M178.
11.
11. Costerton, J. W., B. E. Ellis, K. Lam, R. Johnson and A. E. Khoury. 1994. "Mechanism of Electrical Enhancement of Efficacy of Antibiotics in Killing Biofilm Bacteria,"Antimicrob. Agents and Chemother., 38:2803-2809.
12.
12. Benson, D. E., C. B. Grissom, G. L. Burns and S. F. Mohammad. 1994. "Magnetic Field Enhancement of Antibiotic Activity in Biofilm Forming Pseudomonas aeruginosa,"ASAIO J., 40:M371-M376.
13.
13. Pitt, W. G., M. O. McBride, J. K. Lunceford, R. J, Roper and R. D. Sagers. 1994. "Ultrasonic Enhancement of Antibiotic Action on Gram-Negative Bacteria,"Antimicrob. Agents and Chemother., 38:2577-2582.
14.
14. Qian, Z., R. D. Sagers and W. G. Pitt. 1997. "The Effect of Ultrasonic Frequency upon Enhanced Killing of P. aeruginosa Biofilms,"Annals Biomed. Eng., 25:69-76.
15.
15. Qian, Z., R. D. Sagers and W. G. Pitt. 1997. "The Role of Insonation Intensity in Acoustic-Enhanced Antibiotic Treatment of Bacterial Biofilms,"Colloids and Surfaces B: Biointerfaces, in press.
16.
16. Qian, Z. 1996. "Antibiotic and Ultrasonic Treatment of Bacterial Biofilm," M.S. thesis, Brigham Young University, Provo, UT.
17.
17. Walpole, R. E. and R. H. Meyers. 1978. Probability and Statistics for Engineers and Scientists. New York: Macmillan.
18.
18. Tangy, F., M. Moukkadem, E. Vindimian, M. L. Capmau and F. L. Goffio. 1985. "Mechanism of Action of Gentamicin Components,"Eur. J. Biochem., 147:381-386.
19.
19. Williams, A. R.1983. Ultrasound: Biological Effects and Potential Hazards. London: Academic Press.
20.
20. Yumita, N., R. Nishigaki, K. Umemura, P. D. Morse, H. M. Swartz, C. A. Cain and S. Umemura. 1994. "Sonochemical Activation of Hematoporphyrin: An ESR Study,"Radiation Res., 138:171-176.
21.
21. Rapoport, N., A. Smirnov, A. Timoshin, A. M. Pratt and W. G. Pitt. 1997. "Factors Affecting the Permeability of P. aeruginosa Cell Walls toward Lipophilic Compounds: Effects of Ultrasound and Cell Age,"Archives Biochem. Biophys., in press.
