Assessment of the Biofilm Disruption Activity of Absorbent Sustained-action Dressing with Povidone Iodine

Abstract Body: Objective: Over 65% of bacterial infections treated in the developed world are known to include biofilms, which are less susceptible to host defences or conventional therapies, compared to planktonic counterparts.  More treatment options are needed to combat biofilm infection in wounds.  It is well established that iodine has antimicrobial efficacy however recent reviews suggest that iodine may have a positive role in healing of chronic wounds (1) leading to a re-appraisal of its use in wound care.  A highly absorbent Sustained-action Dressing with Povidone Iodine dressing (SDPI)* with in vitro anti-biofilm activity was developed and the efficacy of the dressing was investigated using an accredited CDC reactor model.     Method: Staphylococcus aureus and Pseudomonas aeruginosa were used to prepare 72-hour single species bacterial biofilms in an accredited CDC reactor model. Following development, biofilm-containing coupons were treated with SDPI dressing containing alginate base and iodine for 24 hours. Following treatment, remaining attached microorganisms were recovered and total viable organisms quantified. All tests were performed in triplicate.   Results: On average > 7 Log10CFUmL-1 P. aeruginosa and > 5 Log10CFUmL-1 S. aureus were recovered from negative control biofilms. Following 24 hours treatment with SDPI dressings, no viable organisms were recovered from biofilm-containing coupons. This equated to reductions of > 4 Log10CFUmL-1.   Discussion: This study demonstrated the biofilm disruption ability of SDPI using accredited and fully validated CDC reactor model. Demonstration of biofilm eradication in vitro provides a strong basis for future work to show the potential for effective treatment in vivo and clinically. Eradication of biofilm infections may result in improved patient outcomes and a decrease in healthcare costs.