title: Presence of biofilm containing viable multiresistant organisms despite terminal cleaning on clinical surfaces in an intensive care unit.
abstract: BACKGROUND
  Despite recent attention to surface cleaning and hand hygiene programmes, multiresistant organisms (MROs) continue to be isolated from the hospital environment. Biofilms, consisting of bacteria embedded in exopolymeric substances (EPS) are difficult to remove due to their increased resistance to detergents and disinfectants, and periodically release free-swimming planktonic bacteria back into the environment which may may act as an infection source.
  
  
  OBJECTIVE
  To establish whether reservoirs of MROs exist in the environment as biofilms.
  
  
  METHODS
  Following terminal cleaning, equipment and furnishings were removed aseptically from an intensive care unit (ICU) and subjected to culture and scanning electron microscopy (SEM). Samples were placed in 5 mL of tryptone soya broth, sonicated for 5 min before plate culture on horse blood agar, Brillance MRSA and Brilliance VRE agar plates. Samples for SEM were fixed in 3% glutaraldehyde and hexamethyldisilizane (HMDS) prior to sputter-coating with gold and examination in an electron microscope.
  
  
  RESULTS
  Biofilm was demonstrated visually on the sterile supply bucket, the opaque plastic door, the venetian blind cord, and the sink rubber, whereas EPS alone was seen on the curtain. Viable bacteria were grown from three samples, including MRSA from the venetian blind cord and the curtain.
  
  
  CONCLUSIONS
  Biofilm containing MROs persist on clinical surfaces from an ICU despite terminal cleaning, suggesting that current cleaning practices are inadequate to control biofilm development. The presence of MROs being protected within these biofilms may be the mechanism by which MROs persist within the hospital environment.
authors: Surgical Infection Research Group, Australian School of Advanced Medicine, Macquarie University, New South Wales, Australia. Karen.vickery@mq.edu.au
authors: K
authors: K
authors: Vickery
authors: A
authors: A
authors: Deva
authors: A
authors: A
authors: Jacombs
authors: J
authors: J
authors: Allan
authors: P
authors: P
authors: Valente
authors: I B
authors: IB
authors: Gosbell
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D003470:Culture Media / Q000737:chemistry; D024901:Drug Resistance, Multiple, Bacterial; D004783:Environmental Microbiology; D017053:Infection Control / Q000379:methods*; D007362:Intensive Care Units; D008855:Microscopy, Electron, Scanning
chemical_list: D003470:Culture Media