Efficacy of local rifampin/minocycline delivery (AIGIS(RX)®) to eliminate biofilm formation on implanted pacing devices in a rabbit model.
OBJECTIVE
Device-related infections represent a significant clinical challenge. Once established, these infections prove difficult to treat with existing antibiotic regimens, compromising the health of device recipients, and usually requiring surgical intervention to resolve. The purpose of this study was to determine the ability of the AIGIS(RX)® Anti-Bacterial envelope to reduce the formation of bacterial biofilm on implanted pacing devices.


METHODS
An infection was established in a rabbit model by creating bilateral subcutaneous implant pockets, into which a pacing device with or without AIGIS(RX)® was placed. The incisions were closed, and a defined dose of bacteria was infused into each implant pocket. After seven days, devices were explanted and assessed for viable bacteria by a sonication/vortex procedure to quantify bacteria, and by imaging of the device surface by scanning electron microscopy and laser scanning confocal microscopy.


RESULTS
The presence of the AIGIS(RX)® envelope eliminated recoverable, viable bacteria from the explanted devices using a vortex/sonication technique from in vivo models of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus capitis, and Escherichia coli infections. Scanning electron microscopy and confocal microscopy demonstrate greatly reduced biological material on the pacemaker surfaces in the presence of the AIGIS(RX)® envelope compared to untreated controls.


CONCLUSIONS
These results demonstrate that in this animal model, the AIGIS(RX)® device reduces the formation of adherent bacteria and reduces bioburden on implanted, infected pacemaker devices.
WuXi AppTec, Inc., St. Paul, Minnesota, USA. linda.hansen@wuxiapptec.com
Linda K
LK
Hansen
Kim
K
Berg
Dave
D
Johnson
Mark
M
Sanders
Mark
M
Citron
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000187:drug effects*; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004866:Equipment Contamination; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D004927:Escherichia coli Infections / Q000382:microbiology / Q000517:prevention & control*; D050296:Microbial Viability; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008911:Minocycline / Q000008:administration & dosage*; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D011817:Rabbits; D012293:Rifampin / Q000008:administration & dosage*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013210:Staphylococcus / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors
D000900:Anti-Bacterial Agents; D008911:Minocycline; D012293:Rifampin