In vitro activity of an engineered honey, medical-grade honeys, and antimicrobial wound dressings against biofilm-producing clinical bacterial isolates

Objective: Honey is recognised to be a good topical wound care agent owing to a broad-spectrum of antimicrobial activity combined with healing properties. Surgihoney RO (SH1) is a product based on honey that is engineered to produce enhanced reactive oxygen species (ROS) and has been reported to be highly antimicrobial. The objective was to investigate the ability of the engineered honey and its comparators to prevent biofilm formation in vitro. Method: We tested the ability of three medical-grade honeys SH1, Activon manuka honey (MH) and Medihoney manuka honey (Med), alongside five antimicrobial dressings (AMDs) to prevent the formation of biofilms by 16 isolates. Honeys were serially double diluted from 1: 3 down to 1: 6144 and the lowest dilution achieving a statistically significant reduction in biomass of at least 50%, compared with untreated controls, was recorded. Results: Although all the honeys were antibacterial and were able to prevent the formation of biofilms, SH1 was the most potent, with efficacy at lower dilutions than the medical honeys for five isolates, and equivalent dilutions for a further six. Additionally, SH1 was superior in antibacterial potency to three commercially available AMDs that contain honey. Conclusion: SH1 is effective at preventing bioflms from forming and is superior to medical honeys and AMDs in in vitro tests.