Wound biofilm: a bacterial success story

Abstract

Background Wound biofilm is one of the greatest challenges in the local therapy of chronic wounds. In clinical practice, it becomes apparent that there are significant differences in the efficacy of wound therapies, although the corresponding guidelines often classify them -due to lack of evidence and knowledge -as "equivalent".Hypothesis Since (almost) no randomised controlled clinical trials (RCT) on antimicrobial local therapies exist, translational research using human biofilm models can further generate information to demonstrate difference and equivalence of topical and physical wound therapies.Methods This narrative, but also scientific, review addresses several anti-biofilm therapies that have been validated in the translational, human biofilm model based on blood plasma, buffy coat, and various bacterial specimens. Bacterial colonisation patterns of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) of patients and ex vivo biofilm models were compared. ResultsSubstantial differences in the anti-biofilm efficacy of antimicrobials, which were often evaluated equally in guidelines, are shown. Octenidine dihydrochloride-phenoxyethanol, polyhexanide (PHMB) and cardexomer iodine perform against biofilm with delay but well. Many antimicrobials fail because of the extrapolymeric substance (EPS) of biofilm, a bacterial product of polysaccharides and (lipo)proteins, acting like a protecting shield. Physical therapies also have their limitations here. ConclusionsThe persistence of biofilm makes wound healing stagnate. Multiple surgical debridement is not the optimal therapy for aged, critically ill patients. Wound biofilm requires a combined topical therapy because it consists of several 'components' . Currently, effective anti-biofilm strategies sustainably removing it from chronic wounds are still lacking. Researchers and manufactures are challenged, because the understanding of wound biofilm is already considerable, promising combined therapies are conceivable, only implementation is still missing.