Efficacy of local rifampin/minocycline delivery (AIGIS_RX®) to eliminate biofilm formation on implanted pacing devices in a rabbit model

Purpose: 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. Conclusion: 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.