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Purpose of the work was to study usability and efficiency of UV decontamination units aboard space station. UV-radiators were high-intensity xenon flashbulbs, as well as standard mercury and amalgam lamps; subjects were reference strains and test-microorganisms isolated from the ISS environment. Quantities of viable airborne and superficial microorganisms were determined before and after UV irradiation. The sanitary-microbiological assessment involved visual and microscopic counting of colony-forming units on material samples (CFU/100 cm2) and Petri dishes after air sampling (CFU/m3 of air). Continuous spectrum of high-intensity pulsed UV was demonstrated to be effective against contamination both by vegetative and high-resistant bacterial spores and molds.

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Subject of the test was a procedure of electron sterilization of Mars descent module units. As a result, data on distribution of absorbed dose field across the surface and by the entire volume of the mockup of a miniature meteorological station (MMS) were obtained In addition, electron sterilization technology was developed and the range of absorbed dose from electron radiation that will sterilize reliably packaged MMS hardware were defined in the interval from 30 to 40 kGy.

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Sensitivity of microflora representatives isolated from inflammatory foci from 40 patients with suppurative-inflammatory diseases of maxillo-facial region and neck to different concentrations of antiseptic preparations of polyhexametylenguanide hydrochloride (Biopag) and chlorhexidine bigluconate was tested. It was determined that 0.05-0.1% solutions of these antiseptics were optimal for these diseases treatment. Biopag had more pronounced fungicidal action, less toxic and more prolonged antimicrobial action and better organoleptic properties when compared with chlorhexidine bigluconate.

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Purpose of the experiment was to define the hypothesized margins of phenotype adaptation and genotype modifications of bacteria-fungi associations that form the typical microbiota on space vehicle materials. The fundamental questions to answer were whether the selected test-cultures would remain vital after extended (comparable to the Mars mission duration) exposure in open space as part of microbesstructural material model systems, and how the space factors would affect microorganisms in the context of eco-safety of space vehicles and planetary quarantine precautions. The first extended (1.5 years) exposure of the model systems outside of the International space station proved survivability of bacterial and microfungal spores in open space. Ultrastructures of eukaryotic and prokaryotic organisms were found altered, and so were their biological properties.

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To get better appreciation of the margins of phenotypic adaptation and genotypic changes in bacteria-fungi associations within the typical microbiota residing on structural materials of space-flown equipment, developed were a program and hardware for a series of experiments under the general name BIORISK. Protocol of each experimental cycle is based on the well-proven method of exposure of "passive" samples of materials (Biorisk-KM), microorganisms-materials systems inside the ISS service module (Biorisk-MSV), and microorganisms-materials systems on the outside of the ISS SM (Biorisk-MSN). Each six months the samples are returned to the laboratory in conjunction with crew rotation. Already the first in-hand data from the experiment point to the dramatic effect of space flight on growth, reproduction, and biological properties of test microbes and fungi. Thus, the activity of enzymes that characterize the pathogenic potential (RNA-ase and DNA-ase), and resistance of microorganisms to aseptic agents were found increased.

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Having bacteriological assay of the material from maxillary sinuses the authors confirmed the presence of fungus infection. There were picked out and identified fungi Aspergillus niger, Candida albicans and Actinomyces israelii. Aspergillus niger can imitate on roentgenograms the picture of foreign body presence in maxillary sinus. Comparison of bactericidal activity of chlorhexedine bigluconate and Biopag showed the advantages of Biopag preparation.

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In 108 K. pneumoniae clinical strains isolated in pneumonia (32 strains), inflammatory processes of the urinary tracts (36 strains) and toxicoseptic states (40 strains) caseinolytic, gelatinase, phosphatase, lecithinase activities and the capacity for producing DNAase and RNAase were studied. The presence of caseinolytic activity was found in 38 cultures (35.1%), gelatinase activity in 37 cultures (34.2%) and lecithinase activity in 13 cultures (12.0%). The production of RNAase was noted in 74 strains (68.5%), DNAase in 56 strains (51.8%) and acidic phosphatase in 33 strains (30.5%). The role of the above-mentioned enzymes in the development of purulent inflammatory processes, as well as the importance of further studies, including those aimed at establishing the nature of the genetic control of the already known properties of the pathogen, are discussed.

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Colonizing and bio-destructive activities and pathogenetic potential of microorganisms isolated from the MIR environment at different phases of its operations were tested and evaluated in comparison with standard "museum" cultures of analogous species. Comparison of bacterial and fungal species revealed certain cultural, biochemical, and morphological distinctions of the "flight" strains. However, to assess the character and the risk associated with peculiar evolution of microflora in long-term space missions, more careful investigations should be followed with the use of the strain genetic labeling and other modern techniques.

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Modeling experiments were performed to evaluate bactericide and fungicide effects of small ozone concentrations (0.3 mg/l of water and 47 mg/m3 of air) that can be generated onboard spacecraft following one hour after treatment. Over the period of treatment, reduction in aquatic microorganisms made up, depending on biotest in use, hundred and more times; concentration of atmospheric microorganisms showed a 5- to 10-fold reduction. The demonstrated effectiveness of ozone shows that it may advantage sterilization and cleaning from microorganisms a number of life support systems aboard manned space vehicles and stations.

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In 1988-89, an experimental was carried out to study the effect of heliogeophysical factors on the biological activity of Staphylococcus aureus, one of the most widespread causative agents of infectious diseases in man and animals. For comparison, both individual heliogeophysical factors and interrelated phenomena in the system Sun-Earth arising from solar flashes were used. Two types of solar flashes were revealed. A near-annual cycle of changes in DNase activity of staphylococci in vitro was revealed, which correlates with the cycle of changes in electron concentration of layer F2 of the ionosphere. The correlation coefficient is 0,96%. It was found that the threshold of susceptibility of test-microorganisms to heliogeophysical influences is different in different years. There is an "amplitude window" of the influence whose upper boundary varies in different periods.

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The in vitro study of effect of such factors as solar activity and the magnetic field of the Earth revealed their influence on the autofluctuations of the biological activity of S.aureus 209 subcultures. Differences in the activity of the synthesis of DNAase, RNAase and delatinase could increase two-- to tenfold during the year. Relationships between heliogeophysical characteristics and the biological activity of bacteria could be both direct and reverse. The study also revealed that at the periods of increased solar and geomagnetic activity S.aureus may spontaneously dissociate in the soil, forming subcultures with greater biological activity than the initial strains.

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The production of three obligatory enzymes (DNAse, RNAse, gelatinase) and of three facultative ones (lecithinase, a-hemolysin, plasma coagulase) by six strains of S. aureus, namely, 209, Smit, Wood 46, phagotype (3A, 3C, 71), (53, 75, 84, 85), and (52A, 79), was investigated, as was the activity of twenty taxonomic parameters in comparison with the cyclic changes of solar activity and magnetic field of the Earth. The follow-up period was two years, from 1988 through 1989. The measurements were taken once a month. Solar activity and geomagnetic field of the Earth were found to influence the autofluctuations of the parameters used to discriminate between S. aureus and S. epidermidis. The activity of formation of pathogenicity enzymes DNAse, RNAse, and gelatinase in the course of a year varied within a wide range: two- to ten-fold. Changes in the aggressive activity of staphylococci were characterized by a cyclic pattern with the cycle duration of about a year. Of the biochemical parameters the most labile were capacity to oxidize lactose, xylite, and D-melibiose, to hydrolyze urea, and the Voges-Proskauter test.

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The authors give considerations to one of the core hygienic problems arising in the process of long-term operation of orbital stations, i.e. ensuring microbial health of the milieu interior. Data pertaining the origin, interactions, and transformation of the microbial risk factors are analyzed as applied to this class of spacecraft. A concept of microbial health of the milieu interior including both medical and technological aspects relating to the reliability of space hardware is proposed. Based on the result of investigations in space flight, the developed criteria and indices of microbial health can be turned to practical use. The currently central tasks to be solved within the context of the problem and in view of the construction of international space station ALPHA are listed.

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The comparative study of the frequency of DNAase and RNAase and the activity of their formation in 59 strains of anaerobic opportunistic bacteria isolated from traumatic and orthopedic patients and in 154 strains of bifidobacteria isolated from feces of healthy persons has been made. The study has revealed that cultures with exonuclear activity occur among opportunistic bacteria and among bifidobacteria, the representatives of human obligate anaerobic automicroflora. However, in opportunistic bacteria the frequency of the above-mentioned enzymes and the activity of their formation have proved to be significantly higher than in bifidobacteria.

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The possibility of the formation of exoenzymes, such as DNAase, RNAase and hemolysin, by bifidobacteria was studied in comparison with their acid-forming and adhesive activity. Bifidobacterium reference strains, originally isolated from healthy adults and children, were studied. The study involved altogether 73 strains of bifidobacteria, including 24 B. bifidum strains, 13 B. adolescentis strains, 7 B. infantis strains, 10 B. breve strains and 19 B. longum strains. The bifidobacteria under study were shown to differ not only in the presence and activity of properties useful for macroorganisms, but also in the presence of enzymes having depolymerizing activity (DNAase, hemolysin). Thus, out of 73 strains under study 9 proved to be DNAase-positive and 6, hemolysin positive. At the same time a specific feature of bifidobacteria was their high acid-forming activity with the complete absence of RNAase activity and insignificant DNAase- and hemolysin-forming activity.

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It is known that the hyperbaric environment facilitates selection of gram-negative microorganisms which acquire ecological predominance. From this point of view deep sea habitats can be regarded as a specific anthropotechnological niche for pathogenic microorganisms, particularly Pseudomonas aeruginosa A. aeruginosa colonization of the mucosa and skin of deep sea divers may result in infection manifestations which took place in chamber experiments when test subjects showed otitis externa and when virulent strains were isolated. It was demonstrated that the basic reservoir of P. aeruginosa was the water supply system. Hence, development of a reliable method for its disinfection should be of highest priority. One of the potential methods is SHF treatment. Another important approach is personal hygiene procedures preventing skin and mucosa contamination with potentially pathogenic microorganisms and procedures for increasing colonization resistance of divers with the aid of eubiotic therapy.

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A study was performed to investigate biological properties of pathogenic microorganisms (Shigella, Salmonella, Staphylococcus aureus) and potentially pathogenic microorganisms which were isolated from different people, i.e. clinically healthy people with normal microflora, somatically healthy patients with intestinal dysbacteriosis, and patients with acute intestinal diseases. The most important parameters of pathogenicity typical of the basic representatives of pathogenic microflora were DNA and/or RNA forming activity. The "critical" size of depolymerization zones of nucleic acids on dense nutrient media was found to be equal to 2 mm and greater from the colony edge. The critical size was shown to be significantly different in potentially pathogenic and normal intestinal microorganisms. Maximal microbial concentrations in the major biotopes of man were estimated to be: no more than 25%, 5% and 2% for nasal mucosa, back skin, and for the large intestine of the total amount of microorganism in the test. Verification of the method gave evidence that in can be applied for an alternative evaluation of automicroflora of the large intestine of operators in an enclosed environment. It is suggested that the normal parameters characteristic of clinically healthy people need to be verified and applied in space and undersea medicine.

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