Antimicrobial resistance has been described as an ‘apocalyptic’ threat to human health requiring urgent action. Resistance to antibiotics is exacerbated because bacteria generally exist in biofilms, which are recalcitrant to antibiotics. The need for new infection treatment options has prompted interest in complex natural products as antimicrobials.
Honey has been used as a topical wound treatment throughout history, predominantly due to its antimicrobial activity. Manuka honey particularly has potent broad-spectrum antibacterial activity, effective against antibiotic resistant pathogens and is currently licensed for use in honey dressings to treat wounds. Importantly, unlike traditional antibiotics, bacterial resistance to honey has not been reported . While an increasing number of health-care professionals include it in the treatment of skin infections and wounds, honey still remains underutilised.
We have shown that manuka honey can prevent and eradicate established biofilms formed by Staphylococcus aureus and Pseudomonas aeruginosa, at concentrations that can be maintained in wound dressings. We also demonstrate that biofilm cell suspensions did not show resistance to honey. Through passaging experiments on culture-grown bacteria, we were not able to isolate bacteria resistant to manuka honey under conditions that rapidly induced resistance to antibiotics. We are currently investigating the mode of action of honey and its major components to better understand how it kills bacteria without resistance developing. This project may lead to new avenues for antimicrobial development such as rational design of honey substitutes, antibiotics, or antibiotic strategies, as well as encourage wider use of an evolutionary answer to resistance in the clinic.