title: Biofilm formation in an experimental water distribution system: the contamination of non-touch sensor taps and the implication for healthcare.
abstract: Hospital tap water is a recognised source of Pseudomonas aeruginosa. U.K. guidance documents recommend measures to control/minimise the risk of P. aeruginosa in augmented care units but these are based on limited scientific evidence. An experimental water distribution system was designed to investigate colonisation of hospital tap components. P. aeruginosa was injected into 27 individual tap 'assemblies'. Taps were subsequently flushed twice daily and contamination levels monitored over two years. Tap assemblies were systematically dismantled and assessed microbiologically and the effect of removing potentially contaminated components was determined. P. aeruginosa was repeatedly recovered from the tap water at levels above the augmented care alert level. The organism was recovered from all dismantled solenoid valves with colonisation of the ethylene propylene diene monomer (EPDM) diaphragm confirmed by microscopy. Removing the solenoid valves reduced P. aeruginosa counts in the water to below detectable levels. This effect was immediate and sustained, implicating the solenoid diaphragm as the primary contamination source.
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Ginny
authors.initials: G
authors.lastname: Moore
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: David
authors.initials: D
authors.lastname: Stevenson
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Katy-Anne
authors.initials: KA
authors.lastname: Thompson
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Parks
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Didier
authors.initials: D
authors.lastname: Ngabo
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Allan M
authors.initials: AM
authors.lastname: Bennett
authors.affiliation: a Biosafety Investigation Unit , Public Health England , Salisbury , UK.
authors.forename: Jimmy T
authors.initials: JT
authors.lastname: Walker
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control*; D060766:Drinking Water / Q000382:microbiology; D004867:Equipment Design; D004865:Equipment and Supplies, Hospital / Q000382:microbiology* / Q000592:standards; D006801:Humans; D011552:Pseudomonas Infections / Q000382:microbiology / Q000517:prevention & control*; D011550:Pseudomonas aeruginosa / Q000254:growth & development*; D006113:United Kingdom; D014871:Water Microbiology / Q000592:standards; D014881:Water Supply / Q000592:standards*
chemical_list: D060766:Drinking Water
keywords: Pseudomonas aeruginosa; biofilm; model water distribution system; non-touch sensor taps; tap water contamination