Magnetic valves as a source of faucet contamination with Pseudomonas aeruginosa?

Sir, We read with interest the paper by Merrer and colleagues [1], suggesting that electronic faucets are a reservoir for Pseudomonas aeruginosa. In previous studies [2, 3, 4], several mechanisms were listed to explain the persistent bacterial contamination of this equipment: low amount of water flowing through the outlet, remaining temperature of about 35°C in the faucet supporting growth of P. aeruginosa, material constituting the magnetic membranes that favors the production of biofilm, and finally the difficulty of flushing out electronic faucets. We propose another possible origin for faucets’ contamination. During renovation work in the neonatal intensive care unit of our hospital, a manual faucet located in the cares