title: Post-Outbreak Investigation of Pseudomonas aeruginosa Faucet Contamination by Quantitative Polymerase Chain Reaction and Environmental Factors Affecting Positivity.
abstract: OBJECTIVE
  To perform a post-outbreak prospective study of the Pseudomonas aeruginosa contamination at the faucets (water, aerator and drain) by culture and quantitative polymerase chain reaction (qPCR) and to assess environmental factors influencing occurrence
  
  
  METHODS
  A 450-bed pediatric university hospital in Montreal, Canada
  
  
  METHODS
  Water, aerator swab, and drain swab samples were collected from faucets and analyzed by culture and qPCR for the post-outbreak investigation. Water microbial and physicochemical parameters were measured, and a detailed characterization of the sink environmental and design parameters was performed.
  
  
  RESULTS
  The outbreak genotyping investigation identified drains and aerators as the source of infection. The implementation of corrective measures was effective, but post-outbreak sampling using qPCR revealed 50% positivity for P. aeruginosa remaining in the water compared with 7% by culture. P. aeruginosa was recovered in the water, the aerator, and the drain in 21% of sinks. Drain alignment vs the faucet and water microbial quality were significant factors associated with water positivity, whereas P. aeruginosa load in the water was an average of 2 log higher for faucets with a positive aerator.
  
  
  CONCLUSIONS
  P. aeruginosa contamination in various components of sink environments was still detected several years after the resolution of an outbreak in a pediatric university hospital. Although contamination is often not detectable in water samples by culture, P. aeruginosa is present and can recover its culturability under favorable conditions. The importance of having clear maintenance protocols for water systems, including the drainage components, is highlighted.
authors.affiliation: 1Department of Civil Engineering,Polytechnique Montréal,Montréal,QC,Canada.
authors.forename: Emilie
authors.initials: E
authors.lastname: Bédard
authors.affiliation: 3Department of Microbiology and Immunology (Infection Control),CHU Ste-Justine,Université de Montréal,Montréal,QC,Canada.
authors.forename: Céline
authors.initials: C
authors.lastname: Laferrière
authors.affiliation: 1Department of Civil Engineering,Polytechnique Montréal,Montréal,QC,Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Charron
authors.affiliation: 2INRS-Institut Armand-Frappier,Laval,QC,Canada.
authors.forename: Cindy
authors.initials: C
authors.lastname: Lalancette
authors.affiliation: 3Department of Microbiology and Immunology (Infection Control),CHU Ste-Justine,Université de Montréal,Montréal,QC,Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Renaud
authors.affiliation: 4Nursing Care Division,CHU Ste-Justine,Montréal,QC,Canada.
authors.forename: Nadia
authors.initials: N
authors.lastname: Desmarais
authors.affiliation: 2INRS-Institut Armand-Frappier,Laval,QC,Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Déziel
authors.affiliation: 1Department of Civil Engineering,Polytechnique Montréal,Montréal,QC,Canada.
authors.forename: Michèle
authors.initials: M
authors.lastname: Prévost
mesh_terms: D002170:Canada; D004866:Equipment Contamination / Q000706:statistics & numerical data*; D050456:Fomites / Q000382:microbiology*; D006785:Hospitals, University; D007362:Intensive Care Units; D015999:Multivariate Analysis; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012044:Regression Analysis; D014871:Water Microbiology; D014881:Water Supply / Q000592:standards*