From the genome of ancient organisms we now move on to ancient therapies for the next #Microtwjc meeting.  This week’s paper (5th June 2012) goes “back to basics” reporting the ability of manuka honey to inhibit Streptococcus pyogenes biofilms and reduce binding to human tissue proteins.

A big thanks needs to go to The Society for General Microbiology (@SocGenMicro) and the journal Microbiology for making this week’s journal open access (until the 7th June 2012).  They have been and will continue to be very supportive of #Microtwjc.

If you have any problems accessing the paper then please let me know!


Streptococcus pyogenes is a problematic organism of clinical significance, whereby infection of skin trauma sites can result in increased patient morbidity and mortality.  The authors first identified the antibacterial effects of manuka honey on both planktonic and biofilm cultures of Group A Streptococcus progenies by growing cells in the presence/absence of manuka honey.  The minimum inhibitory concentration (MIC) was  found to be 20% w/v and the minimum bactericidal concentration (MBC) was found to be 45% w/v with growth analysis showing a dose dependent inhibitory effect.

Having established a bactericidal mode of action, they went on to investigate the effects of manuka honey on biofilms, aggregation, and micro-colony formation.  Manuka honey was effective at permeating established biofilms, killing bacterial cells (reduction in CFU/ml), and reducing the overall biomass of the biofilm (reduction in crystal violet staining).  Microscopy looking at micro-colony formation showed the inability of S. pyogenes to form micro-colonies when grown in sub-lethal concentrations of manuka honey.  Binding of S. pyogenes to human tissue proteins was observed for fibronectin but not fibrinogen at sub-lethal concentrations which were confirmed by end point RT-PCR.

Based on the evidence provided by the authors they conclude that “manuka honey is effective at inhibiting the development of biofilms and disrupting established biofilms of S. pyogenes”.  They go on state that this most likely “mediated by the specific interruption of binding to host tissue ligands” and that manuka honey has potential as a “preventative measure against and treatment for wounds infected with S. pyogenes”.

Discussion Points:

  • Was the paper written clearly and logically with a natural progression of thoughts and ideas through the article?
  • Were the methods robust enough to draw conclusions from?
  • Would you have liked to see any other experiments, maybe some other host tissue proteins tested?
  • Do you agree with the authors closing statements?
  • Finally, is there place for this ancient remedy in modern health care practices?
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