JAC Advance Access originally published online on September 23, 2008
Journal of Antimicrobial Chemotherapy 2008 62(6):1323-1325; doi:10.1093/jac/dkn395
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Original research |
Bacterial colonization of polymer brush-coated and pristine silicone rubber implanted in infected pockets in mice
1 Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands 2 Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
Received 23 June 2008; returned 13 August 2008; revised 25 August 2008; accepted 26 August 2008
* Corresponding author. Fax: +31-50-3633159; E-mail: h.c.van.der.mei{at}med.umcg.nl
Objectives: Curing biomaterial-associated infection (BAI) frequently includes antibiotic treatment, implant removal and re-implantation. However, revision implants are at a greater risk of infection as they may attract bacteria from their infected surroundings. Polymer brush-coatings attract low numbers of bacteria, but the virtue of polymer brush-coatings in vivo has seldom been investigated. Here, we determine the possible benefits of polymer brush-coated versus pristine silicone rubber in revision surgery, using a murine model.
Methods: BAI was induced in 26 mice by subcutaneous implantation of silicone rubber discs with a biofilm of Staphylococcus aureus Xen29. During the development of BAI, half of the mice received rifampicin/vancomycin treatment. After 5 days, the infected discs were removed from all mice, and either a polymer brush-coated or pristine silicone rubber disc was re-implanted. Revision discs were explanted after 5 days, and the number of cfu cultured from the discs and the surrounding tissue was determined.
Results: None of the polymer brush-coated discs after antibiotic treatment appeared colonized by staphylococci, whereas 83% of the pristine silicone rubber discs were re-infected. Polymer brush-coated discs also showed reduced colonization rates in the absence of antibiotic treatment when compared with pristine silicone rubber discs. Tissue surrounding the discs was culture-positive in all cases.
Conclusions: Polymer brush-coatings are less prone to re-infection than pristine silicone rubber when used in revision surgery, i.e. when implanted in a subcutaneous pocket infected by a staphylococcal BAI. Antibiotic pre-treatment during the development of BAI hardly had any effect in preventing the colonization of pristine silicone rubber.
Keywords: implant-related infection , biomaterials , antifouling surfaces , polyethylene oxide , biofilm