Comparison of the antibacterial effects on Pseudomonas aeruginosa and a Staphylococcus aureus biofilm of a class III PHMB releasing foam and a class IIb PHMB non-releasing foam
Chronic wounds are often colonized by different microorganisms, the most prominent being Staphylococcus aureus and Pseudomonas aeruginosa. PHMB-containing dressings have been shown to effectively inhibit bacterial progeny. However, bacteria do not act alone and the concept of biofilm formation and presence is now widely accepted. Therefore, current research targets antibiofilm strategies to restore an optimal wound-healing environment. A combined treatment approach involving debridement and the addition of antibacterial agents may then provide the highest success rates. Here, the efficacy of a new PHMB-releasing PU foam (class III product, MDD 93/42/EEC) against a Staphylococcus aureus biofilm was evaluated in vitro and compared to a non-releasing class IIb (MDD 93/42/EEC) PHMB foam (antimicrobial effect in the foam only). Moreover, antibacterial activity was evaluated in a direct contact method as well as by an extraction-based method against S. aureus and P. aeruginosa.