title: In vivo model of human pathogen infection and demonstration of efficacy by an antimicrobial pouch for pacing devices.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  The purpose of this study was to determine the efficacy of the AIGIS(RX) antibacterial envelope (TyRx Pharma, Inc., Monmouth Junction, NJ, USA) designed to reduce device-related infections by incorporating minocycline and rifampin in a controlled release polymer.
  
  
  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 7 days, devices were explanted and sampled for viable bacteria by swabbing and sonication.
  
  
  RESULTS
  Initial studies evaluated the ability of the AIGIS(RX) pouch to reduce Staphylococcus epidermidis (S. epi) infection in this model using clinical and quantitative microbial endpoints. Results demonstrate S. epi infection in all control samples, while no pathogens were recovered from samples with the AIGIS(RX) pouch. Systemic antibiotic levels were undetectable. Additional studies tested the efficacy of the AIGIS(RX) pouch with additional bacterial strains, Staphylococcus capitis, Escherichia coli, and Acinetobacter Baumannii. In each case, the device and implant pocket with the AIGIS(RX) pouch was free of any signs of infection. An assessment of biofilm produced by Acinetobacter demonstrated the elimination of biofilm formation on the implanted device.
  
  
  CONCLUSIONS
  These results demonstrate that in this animal model, the AIGIS(RX) device reduces the risk for infection of viable pathogens within implant pockets.
authors: WuXi AppTec,Inc., St. Paul, MN 55120, USA. linda.hansen@wuxiapptec.com
authors: Linda K
authors: LK
authors: Hansen
authors: Mary
authors: M
authors: Brown
authors: David
authors: D
authors: Johnson
authors: Donald F
authors: DF
authors: Palme Ii
authors: Charles
authors: C
authors: Love
authors: Rabih
authors: R
authors: Darouiche
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D004195:Disease Models, Animal; D004343:Drug Implants / Q000008:administration & dosage*; D006801:Humans; D016459:Prosthesis-Related Infections / Q000188:drug therapy* / Q000209:etiology*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000209:etiology*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004343:Drug Implants