Leptospermum honey is effective against various types of antibiotic resistant bacteria including Staphylococcus aureus, (MRSA), Acinetobacter calcoaceticus, and Escherichia coli. Additionally the bacteria show no resistance to Leptospermum honey even after repeated exposure (Blair et al. 2009). Leptospermum honey was found to be effective at low concentrations from 4% to 14.8%. It acts differently from other antimicrobial agents by providing moisture, sugars, and hydrogen peroxide as well as an unprecedented number of compounds that have yet to be fully researched. As there are few scientific studies that support the use of honey in wound treatment, more will be needed to understand all of the effects of using honey to treat or prevent infections caused by antibiotic resistant diseases. Kevon White
Blair, E., Cokcetin, N., Harry E., Carter D., 2009. The unusual antibacterial activity of medical-grade Leptospermum honey: antibacterial spectrum, resistance and transcriptome analysis. Eur J Clin Microbiol Infect Dis 28, 1199–1208
S.E. Blair and Colleagues from the University of Sydney and the University of Technology in Sydney conducted several tests using four different types of honey: Medihoney®, Leptospermum honey, Lucerne Blueweed honey, and a controlled artificial honey made from several sugars. The Medihoney® was added slowly to various agar plates containing 13 different types of infectious bacteria. The MIC was then recorded from the results. A marcodilution method test was done later in which all four honeys were diluted with water and was slowly added to the bacteria to determine the MBC of the bacterium. The results of the different honeys were compared with those of Oxcallin, Tetracycline, and Ciprofloxacin. The different honeys along with the three antibiotic medicines were tested repeatedly over the bacterial strains to determine resistance capabilities. Lastly, a macroarray analysis was performed on 6% honey solutions of Medihoney® and the inactive Leptospermum honey. A culture of E. coli was then combined with the honeys to determine the gene expression of the two samples.
The Medihoney® inhibited the growth of bacteria significantly compared to the artificial control honey. The MIC for the Medihoney® ranged from 4%–16% while the artificial honey’s MIC ranged from 20% to beyond 25%. Of the bacteria in the first experiment, MRSA had the least resistance to honey, but it resisted the artificial honey by nearly five times that value. Though the honey is less effective at first, the bacteria do not seem to develop any resistance to it, even after being subjected to repeated trials of honey. When compared to Oxacillin, Tetracyclinen and Ciprofloxacin the percentage of honey needed to inhibit bacterial growth initially was much higher; however, unlike the previous three medicines, the honey does not allow the bacteria to develop a resistance to it. The expression of several E.coli genes when mixed with honey indicates that it may cause a significant change in the protein and binding structures of the bacteria. One-hundred-twenty-four genes were found to be upregulated or downregulated by the presence of honey. Of these genes, most were associated with stress responses in the bacteria. This indicates that honey may have an effect on the bacterial gene sequence and may interfere with protein synthesis. Another suggestion by Blair et al. is that the complex nature of the honey and a yet discovered compound could account for its effectiveness in eliminating antibiotic resistant bacteria. Leptospermum honey has demonstrated the ability to treat an unusually broad number of antibiotic resistant bacteria, and most importantly it is resilient against these strains. Thus its use in western medicine will be important in combating increasingly deadly strains of evolving bacteria.