Evaluation of a Gelling Fiber Dressing with Silver to Eliminate Methicillin Resistant Staphylococcus aureus (MRSA) Biofilm Infections and Enhance the Healing in a Deep Partial Thickness Porcine Wound Model

When facing a strain that has become resistant to various therapies. Methicillin-resistant Staphylococcus aureus (MRSA USA300) is a staphylococcal strain commonly found in hospitals and shown to be resistant to antibiotic treatments. The purpose of this study was to examine a new Gelling Fiber Dressing with Silver using an in vivo biofilm porcine model. Fifty-two deep partial thickness wounds (10mm x 7mm x 1mm) were created and inoculated with MRSA (106 CFU/ml). Wounds were then covered with a polyurethane film dressing for 24 hours to allow biofilm formation. Baseline tissue samples were recovered one day after infection. All wounds were randomly designated to one of the four treatments (12 wounds per group): 1) New Gelling Fiber Dressing with Silver, 2) Gelling Fiber Dressing without Silver, 3) Hydrofiber dressing with silver, benzethonium chloride and ethylenediaminetetraacetic acid (EDTA) or 4) Untreated control. Wounds were recovered for microbiological and histological analysis on days three, five and seven days post treatment. The results showed that the Gelling Fiber Dressing with Silver was able to reduce biofilm associated MRSA more efficiently than the other treatment groups throughout the study. By day seven, wounds treated with Gelling Fiber Dressing with Silver had bacterial reductions of 99.72 and 98.55% when compared against baseline wounds and untreated control, respectively. For the histology analysis, all wounds reached 100% re-epithelialization by day seven. On day three, wounds treated with Gelling Fiber Dressing with and without Silver had a significantly (p< 0.05) thicker epidermis than untreated wounds. These studies suggest that the Gelling Fiber Dressing with Silver is capable of exerting effects against biofilm of antibiotic resistant staphylococcal strains, such as MRSA, without inhibiting the wound healing process. These results may have significant clinical implications when treating acute or chronic wounds.