Manuka honey shows promise for preventing wound infections
MedWire News: Manuka honey has the potential to treat or even prevent persistent wound infections such as those caused by Streptococcus pyogenes, report researchers.
"At present most antimicrobial interventions for patients with infected wounds, are with systemic antibiotics. The use of a topical agent such as manuka honey to eradicate bacteria from wounds is potentially cheaper and may well augment antibiotic therapy in the future," study author Sarah Maddocks (Cardiff Metropolitan University, UK) told MedWire News.
"To date we are not aware of any honey-resistant bacteria, therefore manuka honey could help to overcome some of the problems associated with antimicrobial resistant strains of bacteria," she added.
Maddocks and co-authors have previously demonstrated that manuka honey can kill Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) under laboratory conditions, both of which are known for causing persistent, serious wound infections.
In this study, they tested the ability of manuka honey to eradicate S. pyogenes, a bacterium implicated in a number of infections including necrotizing fasciitis.
The test was carried out in vitro with planktonic and biofilm cultures of the bacteria.
Exposure to manuka honey for 2 hours effectively destroyed 24-hour biofilms of S. pyogenes, causing significant cell death (85%) and removal of cells from the biofilm.
This finding is important, notes the team, as in addition to antibiotic resistance, one of the reasons that wounds infected with S. pyogenes fail to heal is attributed to the bacterium's ability to form resilient biofilms.
Further analysis showed that small amounts (sublethal) of manuka honey were able to prevent S. pyogenes binding to human fibronectin, but not to fibrinogen. This reduced binding ability was confirmed by a reduction in bacterial gene expression of two major fibronectin-binding proteins in response to manuka honey exposure.
When asked what components of manuka honey could be responsible for its antimicrobial activity, Maddocks explained: "One of the antimicrobial compounds that has been identified in manuka honey is methylglyoxal, however this is not believed to be the only antimicrobial compound in manuka honey, there are believed to be many more that as yet have not been identified."
"The research is ongoing," said Maddocks. "We hope to continue to study the antimicrobial effects of manuka honey against different bacteria that have the potential to cause serious wound infection and better understand the precise antimicrobial mechanisms."
By Helen Albert