Biofilms hinder wound healing. Medical-grade honey (MGH) is a promising therapy because of its broad-spectrum antimicrobial activity and the lack of risk for resistance. This study investigated the inhibitory and eradicative activity against multidrug-resistant Pseudomonas aeruginosa biofilms by different established MGH-based wound care formulations. Six different natural wound care products (Medihoney, Revamil, Mebo, Melladerm, L-Mesitran Ointment, and L-Mesitran Soft) were tested in vitro. Most of them contain MGH only, whereas some were supplemented. L-Mesitran Soft demonstrated the most potent antimicrobial activity (6.08-log inhibition and 3.18-log eradication). Other formulations ranged between 0.89-log and 4.80-log inhibition and 0.65-log and 1.66-log eradication. Therefore, the contribution of different ingredients of L-Mesitran Soft was investigated in more detail. The activity of the same batch of raw MGH (1.38-log inhibition and 2.35-log eradication), vitamins C and E (0.95-log inhibition and 0.94-log eradication), and all ingredients except MGH (1.69-log inhibition and 0.75-log eradication) clearly support a synergistic activity of components within the L-Mesitran Soft formulation. Several presented clinical cases illustrate its clinical antimicrobial efficacy against Pseudomonas aeruginosa biofilms. In conclusion, MGH is a potent treatment for Pseudomonas biofilms. L-Mesitran Soft has the strongest antimicrobial activity, which is likely due to the synergistic activity mediated by its supplements.

Objective: Hard-to-heal wounds can be caused by persistent infections or an excess of inflammatory cytokines, proteases and oxidants, and can severely impact the quality of life (QoL) of patients. Due to the paucity of effective treatments and increased resistance to antibiotics, new and improved therapies are required to resolve infections and to simultaneously enhance the healing trajectory. Medical grade honey (MGH) may be a novel and effective treatment approach. Methods: In this case series, we have described six cases of hard-to-heal wounds, and discussed the effects of MGH on infection, wound healing and factors influencing patient QoL (pain, odour and exudate). In all cases, the wounds had persisted for a long period, and previous treatments had been ineffective. Most of the patients had comorbidities, and the majority of the wounds were contaminated with (multiresistant) bacteria, both of which contributed to non-healing. All wounds were treated with L-Mesitran (MGH-based wound care products, Triticum Exploitatie BV, the Netherlands) either as monotherapy or as a complementary therapy. Results: Hard-to-heal wounds started healing, infection was controlled and QoL was strongly improved (malodour, exudate levels and pain swiftly decreased) after the application of the MGH. All wounds healed relatively quickly, considering the severity of the wounds and general health of the patients. Conclusion: In this study, MGH was a useful alternative or complementary therapy to antibiotics and expedited the healing of hard-to-heal wounds.