In-vitro antimicrobial and antibiofilm activities of honey from Apis cerana and Apis dorsata against selected microbial strains of wound pathogens

Introduction: Microbial biofilms play a main role in chronic wounds. Due to the broad-spectrum antimicrobial activity of honey, it has been revisited as an alternative treatment option for chronic wound infections. In this study, we aimed to evaluate the anti-bacterial, anti-candidal, and anti-biofilm effects of natural Sri Lankan Apis cerana, and Apis dorsata honey against selected bacterial, and Candida species. Methods: The physicochemical properties of both honey types were assessed. The antimicrobial efficacy was tested against reference strains of Staphylococcus aureus (including MRSA), Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Candida tropicalis. The agar well diffusion method and Minimum Inhibitory Concentration (MIC) assays were utilized to evaluate antimicrobial activity. Anti-biofilm activity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The ultrastructure of biofilms following treatment with A. cerana honey was visualized via Scanning Electron Microscopy (SEM). Results: The physicochemical properties of A. cerana and A. dorsata honey types were comparable. Both honey types demonstrated antibacterial activity, while anticandidal activity was observed only with A. cerana honey. Both honey types effectively inhibited established biofilms, with A. cerana honey specifically inhibiting initial biofilm adhesion and development. SEM images revealed cell shrinkage in mature sessile cells following treatment with A. cerana honey. Conclusion: Sri Lankan A. cerana, and A. dorsata honey types exhibit potent antimicrobial and anti-biofilm activities, highlighting their potential as wound-cleansing agents for chronic wound management.