Clinical Microbiology and Antimicrobial Chemotherapy. 2011; 13(2):163-167
The objective of the study was to determine incidence and level of contamination of hot water supply systems with Legionella pneumophila in public buildings, including medical care institutions, in Moscow region. A total of 12 public buildings or building complexes, including 7 medical care institutions, in Moscow and Moscow region were examined. Water samples, object washes, and biofilms were tested using conventional microbiologic methods and real-time PCR. The objects demonstrated significant contamination of water supply systems with Legionella pneumophila. This pathogen was found in terminal, and rarely used areas in all hot water supply systems when temperature decreased to 36-52°С. Visual detection of natural biofilms on an object correlated to high concentrations of Legionella in water samples. In some cases, associations of L. pneumophila and P. aeruginosa were found in samples, including water samples from water supply systems in two medical care institutions. The results of this study support an importance of the modern concept of nosocomial legionellosis prevention, which includes a monitoring of Legionella in potentially dangerous water objects and taking prevention measures.