Journal Article

Post-Outbreak Investigation of Pseudomonas aeruginosa Faucet Contamination by Quantitative Polymerase Chain Reaction and Environmental Factors Affecting Positivity

Charron, Dominique, Desmarais, Nadia, Bédard, Emilie, Laferrière, Céline, Prévost, Michèle, Renaud, Christian, Lalancette, Cindy, Déziel, Eric

2015

Overview

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 A 450-bed pediatric university hospital in Montreal, Canada 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. 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. 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.

• Publisher: Cambridge University Press,University of Chicago Press
• Subject: Aerators / Biofilms / Canada / Chlorine / Contamination / Environmental assessment / Environmental factors / Equipment Contamination / Equipment Contamination - statistics & numerical data / Fomites / Fomites - microbiology / Food contamination & poisoning / Hospitals, University / Intensive care / Intensive Care Units / Life Sciences / Multivariate Analysis / Nosocomial infections / Outbreaks / Pediatrics / Physicochemical properties / Polymerase Chain Reaction / Pseudomonas aeruginosa / Pseudomonas aeruginosa - isolation & purification / Pseudomonas Infections / Pseudomonas Infections - epidemiology / Regression Analysis / Water analysis / Water Microbiology / Water sampling / Water Supply / Water Supply - standards / Water temperature