A Surfactant-Based Dressing to Treat and Prevent Acinetobacter baumannii Biofilms

Previous work has demonstrated that a surfactant-based dressing was capable of eliminating any evidence of pre-existing biofilms from an ex vivo porcine skin wound model. Herein, the authors test both the surfactant's ability to prevent biofilm formation and its ability to eliminate Acinetobacter baumannii biofilms. To test biofilm formation inhibition, porcine skin explants were inoculated and incubated for 4 hours before treatment. The explants were then dressed with test or control materials. To test biofilm elimination, mature 3-day biofilms were established and then treated and wiped daily. Explants from each group were harvested daily, and total and biofilm-associated bacterial counts were generated up through day 3 posttreatment. The control explants developed a biofilm with ~106 CFU over the course of 3 days for each of the bacteria tested. The surfactant-treated samples had viable bacteria, but with the exception of a single time point for Staphylococcus aureus without silver sulfadiazine, there was no biofilm formation. Unlike previous results, the surfactants could not eliminate the A. baumannii biofilm, unless it was formulated with relevant antibiotics. The surfactant was effective in preventing the formation of biofilms over a 3-day period. Unlike the authors' previous results, the daily surfactant-based approach alone did not eliminate the A. baumannii biofilms unless relevant antibiotics were included. The data suggest that the surfactants can prevent biofilm formation, but that in the case of a confirmed A. baumannii biofilm, the surfactant must include antibiotics.