[Microbiological monitoring of opportunistic Enterobacteriaceae of the Lena river].

The aim is the study of the circulation, biological activity, persistent potential and genotypic characteristics of opportunistic Enterobacteriaceae of microbial community of the Lena River which is the one of the largest sources of water in Russia and Siberia. Gram-negative component of microbial community in the Lena River was mainly represented by Enterobacteriaceae (80%), including dominated Escherichia (dominant class) and Enterobacter and Klebsiella (subdominant class). In conditions of anthropogenic pollution there is a reorganization of microbial community of the Lena River in the direction of the increase in the proportion of opportunistic pathogens, their species diversity; there is a change of the biological activity of microorganisms, gains of share of strains characterized by antilysozyme activity, hemolytic activity, production DNase, phosphatase. The parameters of system "lysozyme-antilysozyme" are changing, the frequency of the occurrence of bacteria with antilysozyme activity is increasing. This shows the restructurization of the microbial community of water objects. Microorganisms of water objects in territories of anthropogenic pollution are characterized by multiple antibiotic resistance. The proportion of gram-negative opportunistic Enterobacteriaceae in microbial communities of water ecosystems determines the potential danger of water objects and the impact on the level of antibiotic resistance of bacteria. Opportunistic Enterobacteriaceae of microbial community of the Lena River near the city of Yakutsk are characterized by the presence of genetic determinants of pathogenicity (hlyA and sfaG). This is indicative of their potential epidemiological relevance. Microorganisms with high biological activity are markers of their epidemiological danger.

[An assessment of the immune status of the children population as a marker of technogenic pollution of the environment].

This article describes results of the immunological study of school-aged children residing in cities with different levels of the technogenic air pollution. Children from cities with the highest level of the technogenic pollution had a high number of immature neutrophils (band cells) and eosinophils. The children living in these ecologically unfavorable areas have presented a reduction of T-cell antigen receptor CD3, CD4, CD8, CD20, CD16, CD95. This indicates to that both T-cell and B-cell immunity is suppressed. The decline of the phagocytic function in neutrophils indicates to the suppression of the nonspecific host defense mechanisms also.

[Sanitary-Epidemiological Status of Siberian Population (Medico-Demographical and Epidemiological Characteristics)].

Review on the problem of sanitary-epidemiological welfare of the population in the Siberian Federal District (SFD) was conducted based on literature data and authors own research in the period of 2002−2014. Authors provided broad information on the health and demographic and epidemiological characteristics of SFD population. SFD in comparison with other regions of the Russian Federation overcomes one of the most adverse situations including mortality rates from external causes. SFD population's infectious and somatic morbidity rates were analyzed. Analysis demonstrated that the situation relating to priority epidemiologically and socially important infections (HIV-infection, parenteral viral hepatitis, tuberculosis etc.) on the territory of the SFD remains tense. Authors provided information on the increase in the level of the actual for Siberian regions natural-foci tick-borne infections. Detailed analysis for the environment anthropogenic pollution impact for the epidemic, infectious and vaccine induced processes. Authors suggest that anthropogenic (biological) environmental pollution is one of the most important factors influencing the epidemiological welfare of the Siberian population. A new strategic direction in epidemiological research associated with the problem of comorbid diseases is planned.

[Technogenic environmental pollution and the public health: analysis and prognosis].

Technogenic risk factors are very aggressive for a human health. Due to the progressive increase in environmental pollution the problem of the adverse impact of these factors on the health of both the human population as a whole, and individual groups every year is becoming increasingly important. At that the influence of anthropogenic pollution on the various manifestations of infectious pathology in the scientific literature is presented very modestly. In this paper there is presented a review of research devoted to the problem of the interrelationship of man-made pollution of the environment and public health.

[Heterogeneity of microbial communities of surface waters on indices of antibiotic resistance of bacteria].

Microorganisms isolated from reservoirs within urbanized areas, have acquired multiple antibiotic resistance, in this connection during the microbiological monitoring of water objects as an additional criterion of anthropogenic pollution it is worth to take into account indices of antibiotic resistance of bacteria. The study of heterogeneity of microbial communities of largest reservoirs in Eastern Siberia (Angara River and Lena) in terms of antibiotic resistance bacteria was performed from the positions of cluster structuredness. Opportunistic gram-negative bacteria and allochthonous representatives of microbiocenoses of the water bodies were established to be characterized by belonging to four clusters (antibiotic sensitive, mono-, moderately--and poly-antibiotic resistant). At the same time the proportion of microorganisms belonging to different clusters, vary significantly both in terms of different water bodies, and in separate parts of the same body of water, being largely dependent on anthropogenic load on water. Thus, the heterogeneity of the microbial populations permits to present comparative quantitative assessment of reservoirs, as well as their portions, in terms of antibiotic resistance of microorganisms. The increment in the proportion of resistant strains reflects the sanitary and epidemiological importance of this property, because provides evidence of the contamination of water supplies by household sewage.

[Genetic determinants of pathogenicity of opportunistic enterobacteria isolated from children with acute intestinal infections].

AIM: Detection of nucleotide sequences of genes controlling synthesis of pathogenicity factors in clinical strains of opportunistic enterobacteria isolated from children with acute intestinal infections (AII), as well as their association with resistance to antibiotics and the course of the infectious process. MATERIALS AND METHODS: 175 clinical strains obtained from children with AII undergoing treatment in Irkutsk state infectious diseases hospital (2007-2010) were studied. Primers to a number of genes detected in Escherichia coli pathogenicity islands, controlling type S and type 1 adhesion; formation of hemolysins; iron-regulatory protein synthesis; capsule formation were used in the study. PCR products analysis was performed by agar gel electrophoresis. RESULTS: Genetic determinants of pathogenicity were detected in bacteria genera Klebsiella, Citrobacter, Enterobacter, Proteus, Kluyvera, Morganella, Pantoea, Serratia. Fragments of hlyA and hlyB genes (hemolysin production) were detected more frequently; less frequently--sfaA, sfaG, fimA (adhesion), as well as irp-2 gene (synthesis of iron-regulatory protein). The largest set of genetic determinants of pathogenicity was noted in clinical strains of Klebsiella spp. Cultures with DNA fragments specific to genes of E. coli pathogenicity clusters were obtained predominately from children aged up to 3 years, had multiple antibiotic resistance and were isolated significantly more frequently in severe forms of AII when compared with strains in which these determinants were not detected. CONCLUSION: The studies performed showed that clinical strains of opportunistic bacteria isolated from patients with AII have a certain pathogenic potential, as evidenced by the presence of genetic pathogenicity markers in them.

[Biological properties of opportunistic bacteria in aquatic ecosystems].

The paper gives the results of studying the enzymatic activity of bacteria in the microbial community of the Lena River in the central part of Yakutia (the town of Yakutsk and its adjoining areas). The study properties were found in 31.8% of the bacteria. Aeromonas had the highest enzymatic activity. High (22.0%) DNAase production rates were noted in Enterobactericeae.

[Microbiological monitoring of water ecosystems].

The paper presents the results of a study of the microbial community of the Lena River. Active anthropogenic pollution induces structural changes in the microbiocenoses of aquatic objects and increases in the quantity of opportunistic gram-negative microorganisms and in that of antibiotic-resistant bacteria.

[Hygienic assessment of biological reservoir pollution in Eastern Siberia and the North].

The paper presents the characteristics of microbial communities in the water reservoirs of Eastern Siberia and North and their changes depending on the anthropogenic pollution and analyzes antibiotic resistance in microorganisms. The water contamination with pathogenic viruses was revealed in relation to the man-made load, which may be a criterion for assessing the epidemiological situation on the territories.

[Problems of epidemic safety of drinking water use by the population of Russia].

Quantitative relationships were studied between the indicators (common coliform bacteria (CCP), glucose-positive bacteria (GPB), thermoduric bacteria (TDB), coliform bacteria, enterococci, clostridia, coliphages) and the opportunistic (Pseudomonas aeruginosa, Proteus, Klebsiella) and pathogenetic (Salmonella and intestinal viruses) microorganisms at the stages of effluent purification and decontamination, in processes of self-purification in the water reservoirs and of water preparation at water-supplying stations, as well as in the association with the incidence of acute intestinal infections of bacterial and viral genesis in different climatic zones of the country. Salmonella and the opportunistic bacteria of the Enterobacteriaceae family and Pseudomonas aeruginosa were found to be highly resistant to detoxifying agents and environmental factors, adaptable, able to reproduce in pure water, to long survive in underground waters, and to accumulate when water is desalinated at the erections. The cases of intestinal infections were found in the population using the portable water of the standard quality in terms of E. coli, TDB, CCB, and enterococci. In this case only the wider integral index of GPB, which includes the indices of E. coli, TDB, CCB, as well as lactose-negative pathogenic and opportunistic species retains its sanitary significance in terms of all signs and is a reliable indicator of the potential epidemic hazard of drinking water use. Long-term studies have provided evidence for the sanitary value of coliphages as indicators of viral drinking water contamination.