[Rate and level of contamination of potentially dangerous water supply facilities in Moscow region by Legionella pneumophila].

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.

[Assessment of bactericidal activity of disinfectants against Legionella on the biofilm model].

Comparative assessment of bactericidal activity of different disinfectants against Legionella biofilms was conducted. Monospecies biofilms of 3 strains of Legionella pneumophila obtained on plastic plates in stable conditions were used as models. It has been shown that for degradation of biofilms as well as for prophylactic action of disinfectants in preventing formation of biofilms on plastic surfaces, higher concentrations of preparations were needed as compared to their bactericidal concentrations for culture of Legionella determined by method of serial dilutions.

[Multiplication of Listeria in milk products].

The results of the evaluation of the multiplication dynamics of Listeria cells in milk and Bifidok, a lactic acid product, are presented. The samples were inoculated on thioglycol agar and studied at different exposure time after incubation at 37 degrees C, 20 degrees C and 4 degrees C. The study revealed the intensive multiplication of Listeria cells in milk, also during storage in a household refrigerator.

[The detection and study of the dynamics of the count of nonculturable forms of Yersinia pseudotuberculosis in the environment by using the polymerase chain reaction].

On the basis of the polymerase chain reaction (PCR) a test system permitting the detection of Y.pseudotuberculosis in different environmental objects was developed. On a model approximating natural conditions the dynamics of the amount of these bacteria in sterile soil extract were studied.

[Potential hosts and routes of the circulation of Yersinia pseudotuberculosis in an aqueous ecosystem].

The interaction between Y. pseudotuberculosis and different representatives of the aqueous and, partially, soil biocenosis was studied. The study revealed that invertebrates of the plankton and benthos (water fleas, cyclops, mollusks, Oligochaeta, larvae of insects), as well as fish and higher plants, ensured the prolonged existence of Yersinia in water.