Combination of curcumin or chitosan with photodynamic therapy as an effective alternative therapy for overcoming wound infection associated with multidrug-resistant Acinetobacter baumannii

The increasing prevalence of multidrug-resistant Acinetobacter baumannii as an opportunistic pathogen in wound infections raises significant concerns due to its antibiotic resistance and biofilm-mediated antibiotic tolerance. This underscores the urgent need to explore an alternative approach to effectively managing wound infections caused by MDR A. baumannii. In this study, combining subinhibitory concentrations of curcumin (25 µg/ml) or chitosan (156 µg/ml) with photodynamic therapy-PDT (10 J/cm²) resulted in a significant reduction of planktonic viabilities and biofilm biovolume of MDR A. baumannii clinical isolates in vitro. In murine A. baumannii-associated wound infection, a combination of curcumin (25 µg/ml) or chitosan (156 µg/ml) with PDT (10 J/cm²) resulted in complete bacterial eradication with wound healing at Day 15 of post-treatments with these combination therapies. Our study demonstrated that combining curcumin or chitosan with PDT at their subinhibitory concentrations represents a promising alternative strategy as localized therapy for effectively managing A. baumannii-associated wound infection.