Bacterial Contamination Study for In-hospital Water Supply Installation

Abstract

Our hospital experienced an outbreak of multidrug-resistant Pseudomonas aeruginosa (MDRP) in October, 2008. Environmental microorganisms testing, and bacteriological examinations of the nasal cavity, urine, and stool of our hospital patients were undertaken to assess the conditions of MDRP infection and to prevent the infection from spreading. However, our evaluation detected no MDRP, only Pseudomonas aeruginosa, Acinetobacter and Bacillus species. We then assessed microbial contamination of institutional tap water as part of our strategy for prevention of hospital infection by environmental bacteria including MDRP. The survey complied with the Water Supply Act, Japanese Pharmacopoeia and Filtration Enrichment Method on New Legionellosis Prevention Incentives. The survey found no MDRP, but heterotrophic bacteria was detected which may cause opportunistic and healthcare-associated infections by Bacillus cereus and Legionella pneumophila, which are both clinically important. This study shows that the water-supply installation should be periodically cleaned and maintained to prevent bacterial contamination. © 2009, Japanese Society for Infection Prevention and Control. All rights reserved.