title: Reduction of surface contamination and biofilms of Enterococcus sp. and Staphylococcus aureus using a citrus-based vapour.
abstract: BACKGROUND
  Antibiotic-resistant organisms such as meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus sp. (VRE) are an ongoing problem in hospitals. Essential oil vapours (EOs) have been shown to reduce environmental bacterial contamination.
  
  
  OBJECTIVE
  To assess the efficacy of Citri-V™, a vaporized blend of citrus EOs (orange: bergamot, 1:1 v/v) (Belmay, Northampton, UK), at removing Enterococcus sp. and S. aureus from stainless steel surfaces; and to investigate its effect on the formation of bacterial biofilms.
  
  
  METHODS
  A microplate assay was used to assess the effect of the citrus vapour on the formation of biofilms and their metabolic activity. Biofilm removal from stainless steel surfaces was measured by a colorimetric assay and by digital microscopy.
  
  
  RESULTS
  The citrus vapour reduced VRE and MRSA on stainless steel surfaces by 1.5-3log(10) after 24h exposure. Staphylococcal biofilms were reduced both during and after formation, whereas enterococcal biofilms were significantly reduced (P≤0.05) only after formation. Metabolic activity decreased by up to 72% in strains tested. Two-dimensional digital microscopy showed reductions in biofilm coverage of the stainless steel disc by as much as 99.5%.
  
  
  CONCLUSIONS
  Citrus vapour has potential for application in the clinical environment, for instance as a secondary disinfectant to reduce surface contamination by VRE and MRSA.
authors.affiliation: De Montfort University, School of Pharmacy, Faculty of Health and Life Science, Leicester, UK. klaird@dmu.ac.uk
authors.forename: K
authors.initials: K
authors.lastname: Laird
authors.forename: D
authors.initials: D
authors.lastname: Armitage
authors.forename: C
authors.initials: C
authors.lastname: Phillips
mesh_terms: D000336:Aerosols; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002957:Citrus / Q000737:chemistry*; D003124:Colorimetry; D004202:Disinfectants / Q000494:pharmacology*; D016983:Enterococcus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D008853:Microscopy; D009822:Oils, Volatile / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000336:Aerosols; D004202:Disinfectants; D009822:Oils, Volatile