Effect of extremely low-concentration gaseous chlorine dioxide against surface Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii in wet conditions on glass dishes

Healthcare-associated infections due to Gram-negative bacteria (GNB) are a major cause of mortality and morbidity throughout the world. The purpose of the research described here was to evaluate the possibility of using an extremely low-concentration gaseous chlorine dioxide (ClO , 0.01 ppmv, 0.028 mg/m ) as a technique to reduce the risk of environmental infection by GNB. In this study we set up an exposure chamber (1 m ) and used three types of GNB, namely Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii. The extremely low-concentration gaseous ClO inactivated E. coli (> 2 log reductions, within 2 h), P. aeruginosa (> 4 log reductions, within 2 h) and A. baumannii (> 2 log reductions, within 3 h) in wet conditions on glass dishes. Treatment of moist environments with extremely low-concentration gaseous ClO may help to reduce the risk of environmental infection by GNB without harmful effects.