[Express diagnostics of microbial status of humans in 14- and 105-day isolation].

Automated digital image microscopy was used to evaluate skin microbial populations in 14- and 105-day isolation experiments within the Mars-500 project.

[Evaluation of efficiency of automated analysis of microflora from test-subjects during 7-day dry immersion].

Microbial contamination of integument was evaluated in test-subjects volunteered for 7-day immersion with the purpose to evaluate a technology of automated analysis of human microbiocinosis. Integument microflora was investigated in the baseline data collection period and on day-7 of immersion with the help of the standard bacteriological method and using a prototyped automated analyzer. The investigation showed the possibilities of the automated analyzer to provide operating data about human microflora.

[Effectiveness evaluation of the sanitary-hygienic measures during 105-day isolation].

The sanitary-hygienic well-being of 6 volunteers for the 105-d chamber experiment simulating some of the spaceflight factors was evaluated. To evaluate the pertinent means and methods, clinical, hygienic and microbiological investigations were employed, and volunteers' subjective opinions of personal hygiene items and associated procedures were analyzed Based on the examination of integument and oral cavity, entries in the questionnaires concerning subjective sensations, opinions and objective data, all volunteers were invariably in good state. Level of the skin total microbial contamination was found to depend on volunteers' diligence to fulfill the hygienic routine.

[Development of chow for Mongolian gerbils suitable for the conditions of space flight].

One of formidable issues of experiments with animals in space flight is water supply. For Mongolian gerbils (Meriones unguiculatus), classed as cricetid rodents, water in chow is enough. These animals are a new object for space biology. Our purpose was to compose a full-value formula and design a chow making and long-term storage technology to provide Mongolian gerbils for in microgravity. The chow is required to have a 28-d shelf life. To assess the chow suitability on autonomous space fight, the gerbils we house in a cage with the geometry reproducing the current design of the future space animal module. The assessment was performed with adult male gerbils weighing 50.5 +/- 3.4 g on the average. The animals ate up 40.1 +/- 3.9%, i.e. less than 50% of the feed all through the period of experiment. However, by the end of the experiment the body mass and exterior remained essentially unchanged In was concluded that the chow formula can be prescribed to Mongolian gerbils housed in self-contained modules.

[Physiologically active argon-based gas mixtures as a means of creating fire-safe gaseous environments in pressurized modules of varying purpose].

Development of acute hypoxic hypoxia in consequence of fire in various pressurized modules was studied. The investigation was aimed to look into the effects of inert argon and dramatic oxygen reduction in gaseous environment on animals (Wistar rats, mice c57bl/6, balb/c and f1cbaxbalb/c hybrids, Japanese quail embryos) and microorganism (Escherichia coli strains k-12 jf 238 and k-12 jm 83). Also, inflammability of some widely used materials was assessed in order to provide inputs to developers of fire-safe gaseous mixtures for pressurized habitats. It was shown that argon is favorable to survivability of animals and to maintenance of a high level of oxygen consumption. Gaseous mixtures with oxygen content less than 15 volume % suppressed burning of selected materials. Results of the investigation offer possibilities for designing new hypoxic fire-safe gas mixtures that will provide adequate human performance and ensure survival in extreme situations.

[Evaluation of the practicability of linen bed-clothes and underwear in space flight].

The evaluation was performed in a pressurized chamber (ground-based experimental facility) with participation of nine volunteered test-subjects. Linen and cotton underwear and bed-clothes were intercompared by physiological and hygienic well-being of the test-subjects Comparison was made with the help of methods of the sanitary-hygienic assessment and clinical-physiological investigations, and subjective data. Alterations in integument microflora were observed in all the test-subjects irrelative of type of textile. The extent of disbiotic shifts varied with volunteers and did not depend on type of textile. The weighted mean cutaneous and body temperatures were lower in the test-subjects provided with the linen bed-clothes and underwear. According to the clinical investigations, general condition of the test-subjects was stably good no matter type of textile.

[Development of an automated microbiological analyzer].

An automated hematological analyzer, prototype of a quick microbiological diagnostics system, was tested positively for the ability to differentiate microbial cells (six test-strains with different morphological and tinctorial properties) by geometry and dye intensity.

[Effects of medium with elevated partial pressure of argon and nitrogen on morphology of Escherichia coli colonies].

The purpose was to study morphological specifics of microbial colonies cultivated in argon-containing gas medium. Investigated were computerized images of the colonies of museum strains Escherichia coil K-12. It was found that combination of elevated argon pressure (1 ata) and nitrogen pressure (1.8 ata) increased the maximal density of microbial colonies and decreased the colony size as compared with cultivation in argon only.

[Influence of increased partial argon and nitrogen pressure on the R-plasmid Escherichia coli transfer frequency].

Subject of the study was frequency of transfer of bacterial plasmids determining the antibiotic resistance (R-plasmid) in argon-containing gas mixtures. Investigated were reference strains of Escherichia coli K-12. Conjugation took place during incubation in pAr/pN2/pO2, ata (1 ata = 10(5) kPa): No. 1 - 0.0/0.8/0.2 (air control); No. 2 - 1.0/0.8/0/2; No. 3 - 0.0/1.8/0.2; No. 4 - 1.0/1.8/0.2. E.coli conjugation was found inhibited after 24 hrs. of incubation with pAr elevated to 1 ata, whereas elevated partial pressure of argon (1 ata) and nitrogen (1.8 ata) brought transfer frequency down to the minimum.

[Effects of high-pressure argon-containing gaseous compositions on operators' rhinopharynx and external ear microflora and its reactivity to antibiotics]. / Vliianie argonosoderzhashchikh gazovykh sred pri povyshennom davlenii na sostav mikroflory nosoglotki i naruzhnogo ukha operatorov i ee chuvstvitel'nost' k antibiotikam.

Earlier investigations revealed an important microbiological feature of the human in hyperbaric environment--linear progressive unbalance in the opportunistic and commensal ratio within the main biotopes. Change in the gaseous environment may influence the activity of infectious agents. Purpose of our investigation was to study effects of argon-containing gaseous compositions on the rhinopharynx and external ear microflora in operators, and its reactivity to antibiotics. Attempted was quantification of the operators' aerobic microflora exposed for 6, 7 and 18 days to argon-containing gaseous compositions (normoxic and hypoxic) under an elevated pressure (0.15-0.5 MPa). Evaluated was also susceptibility of the human microflora to antibiotics of the basic chemical classes under these conditions. The argon-containing gaseous compositions in the above pressure range did not have any specific effects on the ratio of aerobic gram-negative bacilli and staphylococci; neither they created selective advantages to any of the groups of microorganisms under study. It was found additionally that long-duration exposure in the argon-containing gaseous environment (6, 7 and 18 days) gave rise to cultures with the signs of hospitalism (e.g., high index of multiple drug resistance). Potentiality of infection development in dwelling modules with argon-containing gaseous environment and proliferation of polyresistant strains point to the necessity to design a respective preventive system.