Laboratory Research
Ten deep reticular dermal wounds measuring 4cm x 4cm x 3mm deep were made with a specialized electrokeratome in the paravertebral and thoracic area in three specific pathogen free (SPF) pigs (Looper Farms, NC). All wounds were inoculated with 100 mL of MRSA USA300 at 104 CFU/mL and covered with polyurethane film dressing (Tegaderm; 3M USA) for 72 hours to allow for biofilm formation. Wounds then underwent standard sharp debridement, with two wounds per pig recovered for baseline microbial counts. The remaining wounds were treated with PCMP for a minimum of 5 days with reapplication every 5 days for up to 20 days. Select wounds had PCMP treatment removed after 5, 10, or 15 days to assess whether continuation of treatment was necessary for sustained bioburden reduction and wound closure.
Results: Wounds were assessed for MRSA counts on days 10, 15 and 20. At all assessment time points, wounds treated with PCMP exhibited a lower MRSA count compared to baseline wounds. Furthermore, removal of treatment resulted in resurgence of bioburden, whereas continued PCMP treatment reduced reformation of biofilm with bacterial counts reduced by more than 99%, supporting continual treatment through wound closure with PCMP to prevent microbial proliferation.
Discussion: These studies may have important clinical implications in the use of tissue matrices with antimicrobials to reduce costly wound infections in large wounds.