[DISTRIBUTION OF BACTERIA OF THE KLEBSIELLA STRAIN IN WATER OBJECTS AND THEIR VALUE IN DEVELOPING OF THE WATER CAUSED ACUTE INTESTINAL INFECTIONS].

The wide circulation of Klebsiella bacteria in water ofwater objects of different climatic zones of Russia and various function is established. So bacteria of the Klebsiella strain are in superficial sources of the centralized water supply depending on extent of their biological and chemical pollution; underground waters at the unprotected water-bearing horizons; in drinking water at insufficiently effective system of its cleaning and disinfecting. Klebsiella circulating in water was shown to keep properties of pathogenicity and a virulence, possess resistance both to modern preparations and disinfecting agents (chlorine, an ultraviolet to radiation). Bacteria of the Klebsiella strain have high penetration in the water-bearing horizons. At strains of Klebsiella there is allocated considerable pathogenic potential (adhesive, invasive, phosphatase, lecithinase, DNA-ase, hemolytic activity) and genetic markers of pathogenicity of cnf-1. The etiologic role of bacteria of Klebsiella and an infecting (100, COE/dm3) dose emergence of acute intestinal infections (AII) is established. Detection of Klebsiella in water objects and especially in water of drinking appointment, in the absence of total coliform bacteria (TCB) contributes to the epidemic danger of water use.

[Application of the new culture medium for the isolation of Salmonella from water bodies to assess the epidemic safety of water use. Gigiena i Sanitaria (Hygiene and Sanitation, Russian)].

There was developed a liquid storage medium for the isolation of bacteria of genus Salmonella from water bodies (The culture medium for the accumulation of Salmonella, ready to use, "RNS"), providing the accumulation of Salmonella from different serogroups, inhibiting the growth of accompanying microflora, allowing to obtain objective information about the extent of bacterial contamination of water bodies. Medium is by nature of a solution for microbiological purposes which is produced by mixing the components with consequentfiltration and sterilization. In an experimental way there were chosen optimal ratios of the nutrient medium ingredients: extract offodder yeast in an amount of 4.55.0 g/l, sodium hydroxide - to 1.3-1.4 g/l, potassium phosphate - 8.6-8.8 g/l. The medium is a sterile, clear liquid, green in color, medium pH is 6.4 to 6.8, amine nitrogen - from 0.05 to 0.1%. Designed medium for accumulation is sensitivity, it ensures the growth of the test strains of salmonella at seeding of single cells in that favorably differs from similar media used in public health practice at the present time. The smallest time for the accumulation of biomass of Salmonella accounts of 6 hours, the optimal time is 24 hours. Incubation of crops is produced at 37 °C. Cultures of Salmonella at seeding in the developed medium retain their biological properties. Developed medium in terms of sensitivity is superior to magnesian and selenite media.

[Comparative assessment of sanitary and epidemic importance of indicator coliform indices of drinking water quality].

The used methodology of the scientific substantiation of indicators is in the establishment of the conformity of laws of vital activity of indicator and pathogenic microorganisms in the real conditions of the action of the complex of factors, including disinfecting agents. In the one water sample simultaneously there were determined both the general indicator (GICB), thermotolerant (TTCB), glucose positive (GPCB) coliform bacteria, E.coli. On the base of long-term research in the various regions of the Russian Federation, as well with bearing in mind the analysis of domestic and foreign data, comparing the water quality and the incidence of intestinal infections in population it is recommended to use the index of determination of the total number glucose positive coliform bacteria (GPCB), which brings together a much broader range of bacteria of the Enterobacteriaceae family in comparison with total coliform bacteria (TCB) and thermotolerant coliform bacteria (TTCB) and warrants the absence in the test volume of water as an indicator lactose positive (E.coli, TCB, TTCB) and pathogens (salmonella) and potentially pathogenic bacteria which do not ferment lactose. Proposed index of GPCB is shown to allow to assess epidemiological risks not only more accurate, but also more efficiently without increasing the cost performance of bacteriological research.

[study in the experimental conditions of pesticide action on microorganisms characterizing sanitary-epidemiological safety of reservoirs].

The paper presents experimental data on the pesticides action (molinate (OrdramA), Dinitroortocresolum and chlorophos) at concentrations of 0.01 mg /l to 10 mg/l on sanitary-indicative (TBC, total coliform bacteria, E. coli, E. faecalis), potentially pathogenic ( Ps. aeruginosa) and pathogenic (S. Derby) microflora of the river water. As the test cultures there were used isolated from the reservoir and museum strains of microorganisms. Due to the fact that the rate of decomposition ofpesticides in water increases in direct proportion to the extent of its biological contamination, the experiments were performed with the river water: native and sterilized by autoclaving. There were identified species and strain differences in the microbial response to the action of pesticides. The selectivity of OrdramA action at a concentration of 0.1 to 10 mg/l on Salmonella and of chlorophos at a concentration of 10 mg/l for Salmonella and E. coli is manifested in the stimulation of the reproduction of these bacteria. Dinitroortocresolum in concentrations of 10 mg/l and 1 mg/l gives rise in the reproduction of Pseudomonas aeruginosa and inhibits the growth of total coliform bacteria and E. coli, in a concentration of 0.1 mg/l the preparation stimulates the viability of all the studied microorganisms. When entering the body of water, pesticides were found to cause changes of biocenosis in the river water and disturb bacterial self-cleaning processes. In conditions of pesticide pollution total coliform bacteria, E. coli and E. faecalis unable to maintain their indicative value and therefore the use of only them for the evaluation of the sanitary-epidemiological status of the water source appears to be insufficient. Due to the fact that the epidemic potential of water is directly dependent on quantitative content ofpathogenic and opportunistic pathogenic microorganisms in it, the reproduction Salmonella and Pseudomonas bacteria is a negative moment from the sanitary and epidemiological point of view.

[The importance of sanitary microbiological indices in the evaluation of epidemiological safety of water use in conditions of chemical contamination of water].

The increasing chemicalization of production and life leads to the pollution of water bodies by chemicals, the effect of which on the micro - and macro - organisms is poorly understood. This section of the study in sanitary bacteriology is becoming ever more topical and is an important task of modern hygienic science. One of complicacies of the study of the problem is related with the fact that the presence of only experimental data fails to be sufficient, as the impact of any given chemical substance on different bacteria in the experiment does not mean that under natural conditions, similar results will be obtained. One reason for this may be the inhibitory effect of the given chemical on biological properties of bacteria, while in field conditions in the water several chemicals interacting with each other can exist. In this regard, the aim of the work was to assess the indicator value of sanitary and microbiological indices of epidemic hazard of water use in conditions of chemical pollution of surface water bodies.

[STUDY OF THE IMPACT OF CERTAIN ENVIRONMENTAL FACTORS ON THE VIABILITY OF THE SALMONELLA BACTERIA IN WATER FOR THE DETECTION OF ITS EPIDEMIC POTENTIAL].

Salmonella from the tail water of the Don river was shown to be detected in 31.4% of samples with an average index of 23.5. Under experimental conditions, revealed long-term survival of Salmonella in the water exceeded in most of the experiments terms of preservation of E. coli and E. faecalis. The calculated high level of microbial risk of emergence of intestinal infections suggests the possibility ofwater route ofsalmonellosis.

[The significance of glucose positive coliform bacteria and potentially pathogenic bacteria as an indicator of epidemiological safety of tap water].

Due to intensive anthropogenic pollution of water environment generally accepted indicators of epidemic security of water bodies--common bacteria (CB) and thermotolerant coliform bacteria (TCB) do not always permit to obtain an objective characterization of bacterial contamination of tap water. From the point of view of authors the integral index--glucose positive coliform bacteria most adequately reflect the sanitary-hygienic and epidemiological situation of water bodies. In monitoring for bacterial quality of tap water it is advisable to determine glucose positive coliform bacteria, that will provide the relevance of estimation of the epidemiological safety of water use. According to the method developed by the authors the calculation of the index of population risk of acute intestinal infections (AHI) occurrence in dependence on the quality of tap water in Azov and Tsimlyansk towns.