Aim: To assess rate and level of contamination by Legionella pneumophila of cooling water systems in industrial facilities as well as hot water supply systems of administrative buildings in Moscow region.
Materials and methods: Cooling water systems of 8 industrial facilities and hot water supply systems of 12 administrative buildings or complexes located in Moscow or Moscow region were examined. Samples of water, washes and biofilms were studied by bacteriologic methods and RT-PCR. Results. Significant level of contamination of water systems by L. pneumophila was revealed in examined objects. Rate of contamination of cooling water systems in industrial facilities was 70%. The agent was detected in stagnant, end-capped, and rarely used segments of all hot water supply systems during decrease of water temperature to 36-52 degrees C. Visual detection of natural biofilms on the object correlated with high concentration of L. pneumophila in water samples. In some cases, associations of L. pneumophila with Pseudomonas aeruginosa were detected, including water samples from supply systems of 2 healthcare facilities.
Conclusion: Obtained results confirm the importance of implementation of modem concept of legionellosis prevention in our country, based on regular quantitative monitoring for Legionella in potentially dangerous water objects and conduction of preventative measures if contamination exceeds acceptable level.