Open AccessUltrasonic Enhancement of Antibiotic Action on Escherichia coli Biofilms: an In Vivo Model
Author(s) -
Andrea M. Rediske,
Beverly L. Roeder,
Maren K. Brown,
Jared L. Nelson,
Rachel L. Robison,
David Draper,
G. Bruce Schaalje,
Richard A. Robison,
William G. Pitt
Publication year - 1999
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.43.5.1211
Subject(s) - gentamicin , aminoglycoside , in vivo , antibiotics , biofilm , escherichia coli , ultrasound , microbiology and biotechnology , ultrasonic sensor , biomedical engineering , bacteria , materials science , medicine , chemistry , biology , radiology , biochemistry , genetics , gene
Biofilm infections are a common complication of prosthetic devices in humans. Previous in vitro research has determined that low-frequency ultrasound combined with aminoglycoside antibiotics is an effective method of killing biofilms. We report the development of an in vivo model to determine if ultrasound enhances antibiotic action. Two 24-h-oldEscherichia coli (ATCC 10798) biofilms grown on polyethylene disks were implanted subcutaneously on the backs of New Zealand White female rabbits, one on each side of the spine. Low-frequency (28.48-kHz) and low-power-density (100- and 300-mW/cm2 ) continuous ultrasound treatment was applied for 24 h with and without systemic administration of gentamicin. The disks were then removed, and the number of viable bacteria on each disk was determined. At the low ultrasonic power used in this study, exposure to ultrasound only (no gentamicin) caused no significant difference in bacterial viability. In the presence of antibiotic, there was a significant reduction due to 300-mW/cm2 ultrasound (P = 0.0485) but no significant reduction due to 100-mW/cm2 ultrasound. Tissue damage to the skin was noted at the 300-mW/cm2 treatment level. Further development of this technique has promise in treatment of clinical implant infections.