Eradication Effect of Electrolyzed Hypochlorous Acid Water Produced by Electronic Bidet Toilet Seat System Against Pseudomonas Aeruginosa

In recent years, specifications with more stringent hygienic requirements have been needed for toilet seats with electronic bidet sprayers to prevent their contamination and transmission of pathogens responsible for healthcare-associated infections. Some of the latest models of bidet toilet seats are designed to electrolyze tap water and produce hypochlorous acid water (neutral electrolyzed water) to cleanse the spray nozzles. This study was performed to clarify the optimal conditions of nozzle cleansing eradication of bacteria effect with low-concentration neutral electrolyzed water using clinical and environmental isolates of Pseudomonas aeruginosa as a common pathogen causing healthcare-associated infection. Exposure to neutral electrolyzed water having a chlorine concentration of 0.5 mg/L for 30 s or longer, or of 1.0 mg/L for 5 s or longer, led to a 2-log or more decrease in the level of P. aeruginosa for 90% or more of the strains of both clinical and environmental isolates, thereby demonstrating the eradication of bacteria effect. The results suggest that, for eradication of bacteria against P. aeruginosa , neutral electrolyzed water is effective even at low concentrations, provided that the exposure time and intervals are optimized.