Povidone-iodine in polyethylene oxide hydrogel dressing. Effect on multiplication of Staphylococcus aureus in partial-thickness wounds

• We studied the ability of a polyethylene oxide hydrogel dressing (Vigilon) containing povidone-iodine to preventStaphylococcus aureusproliferation in partialthickness wounds. We previously reported that a single application of povidone-iodine on wounds challenged with 2 × 10⁶S aureuswas not effective in reducing the number ofS aureusafter 24 hours. It was therefore hypothesized that povidone-iodine might be effective if it was available continuously and applied to wounds containing a smaller number of bacteria. To test this hypothesis, we made multiple partial-thickness wounds (5 × 7 ×0.3 mm) on six domestic pigs. We then inoculated the wounds by scrubbing them with either a low concentration (log 3.5) or a high concentration (log 7) ofS aureussuspension. The wounds were either treated with Vigilon or Vigilon containing povidone-iodine or left air exposed. Wounds from each of these treatment groups were cultured by the scrub technique forS aureuswith a 0.5% sodium thiosulfate-polysorbate (Tween) 80 solution 5 minutes, 30 minutes, 24 hours, or 48 hours later. A significant reduction in the number ofS aureusrecovered from wounds treated with Vigilon containing povidone-iodine was seen with the group inoculated with a low bacterial concentration after 24 hours; but no reductions were observed when wounds were inoculated with the higher bacterial concentration of log 7. We found Vigilon containing povidone-iodine to be an effective inhibitor ofS aureusin wounds over a 24-hour period when the organism was present in low numbers. (Arch Dermatol1986;122:1133-1138)