Impact des différents types de robinets sur l'occurrence de pseudomonas aeruginosa dans l'eau des grands bâtiments

This study aims to clarify whether electronic faucets are more or less colonized than conventional faucets, to assess whether the connecting pipes or some physicochemical parameters can influence contamination at the tap, determine the area of proliferation within the cold distribution system and compare two methods for quantification of P. aeruginosa, culture (ISO 16266) and enzyme detection (Pseudalert IDEXX ™). More than 200 taps have been characterized and sampled to assess the prevalence of P. aeruginosa in four hospitals between March and July 2013. The breakdown between types of taps was: 105 electronic faucets, 90 manual and 14 foot operated faucet. Among these faucets, many were located in areas where patients are most at risk of contracting infections, including the intensive care units, operating rooms, haemato-oncology and transplant. For each faucet, a liter from first flush of cold water was collected and analyzed by culture according to the ISO 16266 protocol and enzymatic detection method with Pseudalert (IDEXX ™). Also, swabs of drains and aerators were cultured. All characteristics of taps, drains and connecting pipes were recorded. The following physico-chemical parameters were measured: copper, residual chlorine, flow rate and temperature of hot water after 1 minute. Moreover, a sequential sampling of small volumes of water was performed on water taps that were positive for P. aeruginosa to determine the source of contamination. Finally, a laboratory test was conducted on connecting pipes.