Manuka honey may help prevent infections in hospitals: study

London: Diluted Manuka honey may be a powerful remedy against growth of bacterial biofilms in medical devices, and may be use to reduce the risk of
infections in hospital patients, a new study has found.

Manuka honey is a monofloral honey produced in Australia and New Zealand from the nectar of the manuka tree. According to the research by University of Southampton in the UK, even low dilutions of Manuka honey can curb the
activity and growth of bacterial biofilms - the thin but resilient layer of microbes.

The research raise the prospect of the honey's potential use in patients fitted with medical devices, such as urinary catheters, which carry a high infection risk.
Around 100 million urinary catheters, used to drain the bladder of urine, are sold worldwide every year. Up to one in four hospital patients may have to use a
catheter. However, long-term use is associated with frequent complications, such as inflammation and infection.

"We have been able to demonstrate that diluted honey is potentially a useful agent for reducing biofilm formation on indwelling plastic devices such as urinary catheters," said Bashir Lwaleed, associate professor at the University of
Southampton, who led the study. "Catheter infection rates can account for a large
proportion of hospital acquired infections - it is an area of clinical practice that needs addressing," he added.

"We believe that patients might also benefit from honey's anti-inflammatory properties, which are generally stronger in dark honeys, such as Manuka and that antibacterial resistance is unlikely to be a factor when honey is used," he said. To find out if Manuka honey has a role in stopping the establishment and development of biofilms, the researchers cultured strains of Escherichia coli and Proteus mirabilis bacteria on plastic plates in the laboratory.

These two bacteria account for most of the urinary tract infections associated with long-term catheter use. The honey was diluted with distilled water and added to medium to give different 'strengths', 3.3 per cent, 6.6 per cent, 10 per cent, 13.3 per cent, and 16.7 per cent.

In the first part of the experiment, the various dilutions were added at the same time as the bacteria in two of the wells of each of the 96 plates, and just plain medium or artificial half strength honey to the other two wells. These were then sealed and incubated for 24, 48, and 72 hours to see whether the honey had any effect on the formation of a biofilm.

In the second part of the experiment, honey was added after 24 hours and incubated for either a further 4 or 24 hours to see if honey restricted growth of the biofilm. The results showed that Manuka honey strongly inhibited the 'stickiness' of the bacteria, and therefore the development of a biofilm.

Even at the lowest dilution, it curbed stickiness by 35 per cent after 48 hours compared with the plain medium and artificial honey. The study appears in the Journal of Clinical Pathology.