title: Manuka honey inhibits cell division in methicillin-resistant Staphylococcus aureus.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of manuka honey, artificial honey and an antibacterial component (methylglyoxal) on cell division in methicillin-resistant Staphylococcus aureus (MRSA).
  
  
  METHODS
  Viability of epidemic MRSA-15 NCTC 13142 incubated with manuka honey, artificial honey and methylglyoxal was determined, and structural effects monitored by electron microscopy. Activity of murein hydrolase (a peptidoglycan-degrading enzyme implicated in cell separation, encoded by atl) was estimated by cell wall hydrolysis and zymography; expression of atl was quantified by real-time PCR.
  
  
  RESULTS
  Growth of MRSA was inhibited by 5%, 10% and 20% (w/v) manuka honey and 10% (w/v) artificial honey containing methylglyoxal, but not 10% (w/v) artificial honey. Statistically significantly increased numbers of cells containing septa and increased cell diameter (P < 0.001 and P < 0.001, respectively) were found in MRSA exposed to 5%, 10% or 20% (w/v) manuka honey, but not 10% (w/v) artificial honey with and without methylglyoxal. Intracellular activity of murein hydrolase was elevated in MRSA grown in 10% (w/v) artificial honey and at undetectable levels in MRSA treated with 10% (w/v) manuka honey. Increased atl expression was found in MRSA treated with 10% (w/v) manuka honey and 10% artificial honey containing methylglyoxal.
  
  
  CONCLUSIONS
  Enlarged cells containing septa were observed in MRSA exposed to inhibitory concentrations of manuka honey, suggesting that cell division was interrupted. These changes were not caused by either the sugars or methylglyoxal in honey and indicate the presence of additional antibacterial components in manuka honey.
authors: University of Wales Institute Cardiff, Western Avenue, Cardiff CF5 2YB, UK.
authors: Rowena
authors: R
authors: Jenkins
authors: Neil
authors: N
authors: Burton
authors: Rose
authors: R
authors: Cooper
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D006722:Honey; D031649:Leptospermum; D055624:Methicillin-Resistant Staphylococcus aureus / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism*; D028321:Plant Preparations / Q000494:pharmacology*; D011765:Pyruvaldehyde / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy
chemical_list: D000900:Anti-Bacterial Agents; D028321:Plant Preparations; D011765:Pyruvaldehyde; D009238:N-Acetylmuramoyl-L-alanine Amidase