Multi-year monitoring of atmospheric bioaerosol in Southwestern Siberia revealed the presence of a large number of various culturable microorganisms. It is known that viable microorganisms can cause directly or provoke different human diseases. It's very difficult to evaluate the danger represented by each microorganism to man directly. Therefore, a relatively simple method is required for evaluation of potential danger represented to man by the whole assembly of culturable microorganisms in an atmospheric aerosol sample. For bacteria, the method can be based on a number of individual characteristics of each microorganism determined in the course of biochemical and other test required for identification of the detected bacterium, and a number of other tests. It is proposed to classify the measured individual characteristics of bacteria under four groups of indices responsible for: (i) potential pathogenicity for man; (ii) the numbers of bacteria in the sample; (iii) resistance to unfavorable environmental factors; (iv) drug resistance of bacteria. Each of four groups of indices is numerically evaluated by a certain integral index, which quantitatively reflects the contribution of experimentally determined characteristics of bacteria. Expert evaluation of the contribution of each characteristic of microorganisms to the corresponding group of indices is performed. The generalized index of potential danger of culturable bacteria in atmospheric aerosols for human health is presented as the product of four integral indices summarizing the normalized individual integral indices for all bacteria detected in the sample. The work presents the results of measuring the variations of all the above indices for atmospheric air samples collected during one year.

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Antimicrobial resistance and plasmid profile of Gram-positive and Gram-negative bacterial strains isolated from the urbanized Eltsovka-1 River (Russia) were investigated. Sequencing of the 16S rRNA of of G+ strains showed 99-100% identity to that of Bacillus aerophilus, Bacillus altitudinis, Bacillus amyloliquefaciens, Bacillus anthrancis, Bacillus barbaricus, Bacillus cereus, Bacillus flexus, Bacillus indriensis, Bacillus stratosphericus, Bacillus subtilis subsp. subtilis, Bacillus thuringiensis, Streptomyces albidoflavus, Streptomyces albus, Streptomyces exfoliatus, Streptomyces odorifer, and Streptomyces sampsonii. Sequencing of the 16S rRNA of G-strains was similar in 99-100% to that of Aeromonas bestiarum, Aeromonas encheleia, Aeromonas hydrophila, A. hydrophila subsp. anaerogenes, A. hydrophila subsp. dhakensis, Aeromonas media, Aeromonas molluscorum, Aeromonas popoffii, Aeromonas salmonicida subsp. masoucida, A. salmonicida subsp. pectinolytica, A. salmonicida subsp. salmonicida, Aeromonas punctata, Aeromonas sobria, and Shewanella putrefaciens. The highest percentage (88.4%) of strains was resistant to polymyxin B followed by 69% to lincomycin, 61.5% to benzilpenicillin, 57.7% to ampicillin, and 50% to carbenicillin. A low level of resistance (4%) was found to kanamycin (8%), to streptomycin (11.5%), to neomycin and tetracycline, and (15%) to erythromycin. No resistance was found to gentamycin, monomycin, and chloroamphenicol. The majority (80.7%) of strains was multidrug-resistant. Ninety-two percent of all strains carried plasmid DNA of various sizes.

To contribute to the comprehensive study of atmospheric pollution in Siberia, aircraft soundingwas carried out in Northwestern Siberian along the following route: Novosibirsk – Surgut – Igarka – Novosibirsk. This work was aimed at studying the quantity and representation of culturable microorganisms and other biogenic components of the atmosphere at altitudes up to 8,000 m. The air samples were collected to impingers (flow rate 50 ± 5 L/min) where 50 ml of Hanks’ solution (ICN Biomedicals) was used as the sorbing liquid and applied on the fibrous filters. The concentration of biogenic material was recorded, and the concentration and diversity of culturable microorganisms were determined in total protein samples. It was found that the samples of atmospheric air contained 158 mesophilic and psychrophilic microorganisms represented by such genera as Micrococcus, Staphylococcus, Bacillus, Nocardia, Arthrobacter, and Rhodococcus. Also, Actinomycete, yeast and fungal cultures were also iso-lated. Non-sporiferous bacteria were widely presented at all altitudes. Enzymatic activity of the isolated microorganisms and a number of pathogenicity factors present were investigated. The data on quantity and representation of culturable microorganisms and other biogenic components at altitudes up to 8000 m in Northwestern Siberia were obtained for the first time. It is a significant contribution to the study of the atmosphere of this region. The patterns of the observed biodiversity of microorganisms, associated with the sampling altitude or geographic location, should be determined infurther research.

The concentration and diversity of cultivated bacteria and fungi isolated from samples of atmospheric aerosols taken during airborne sounding of the atmosphere at altitudes from 200 to 10,000 m above the seas of the Russian sector of the Arctic: the Barents Sea, the Kara Sea, the Laptev Sea, the East Siberian Sea, the Chukchi Sea, and the Bering Sea. Most of the samples analyzed showed the presence of pathogenic and opportunistic bacteria and fungi that can cause infectious and allergic diseases.