Preliminary results of cytos 2 experiment

Tixador, R.; Richoilley, G.; Gasset, G.; Planel, H; Moatti, N.; Lapchine, L; Enjalbert, L; Raffin, Jean P.; Bost, R.; Zaloguev, S. N.; Mp, Bragina; Moroz, A F; Antsiferova, N.G.; Kirilova, F. M.

doi:10.1016/0094-5765(85)90082-7

Cited by 44 publications

(38 citation statements)

References 2 publications

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“…3). This is in marked contrast to results obtained with a S. aureus strain isolated from the automicroflora of the astronaut J. L. Crétien; when cultured in nutritionally complex medium aboard Salyut 7 in July 1982, electron microscopy revealed large increases in the thickness of the cell wall in comparison to the earth control [10,12]. The reasons for this disparity are unclear but factors other than microgravity may have been brought to bear during the space flight experiments.…”

Section: Resultscontrasting

confidence: 53%

“…The reasons for this disparity are unclear but factors other than microgravity may have been brought to bear during the space flight experiments. In marked contrast to in-flight investigations conducted in nutritionally complex medium with the Crétien S. aureus isolate [10,12], we found no changes in the susceptibility of RF1, RF6 and RF11 to the acrolide antibiotic erythromycin, the β-lactam flucloxacillin and the glycopeptide vancomycin ( Mo cyt blo the nt bacterial toxins known and ontributes significantly to morbidity and mortality th in a microgravity environment had an ct on a number of factors associated with the less protein than NG-cultured bacteria an quantity of some virulence of S. aureus. The majority of S. aureus strains produce carotenoid pigments that impart the golden hue to colonies of this pathogen; the main pigment is staphyloxanthin, a triterpenoid esterified with a C15 fatty acid [25].…”

Section: Resultsmentioning

confidence: 99%

“…Treatment of on-board infections could be compromised by reversible increases in antibiotic resistance. Experiments aboard Soviet [10,11] and American [12,13] vessels have indicated that the antibiotic susceptibility of both Gram-positive and Gram-negative bacteria may be significantly reduced during flight. For example, the minimum inhibitory concentration (MIC) of colistin and kanamycin required to kill Escherichia coli increased fourfold in comparison to ground experiments when determined aboard Salyut 7; the reduction in oxacillin, erythromycin and chloramphenicol susceptibility of a S. aureus isolate was accompanied by large increases in the thickness of the cell wall, an effect often intimately associated with changes in sensitivity to antibiotics.…”

Section: Introductionmentioning

confidence: 99%

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Effect of simulated microgravity on the virulence properties of the opportunistic bacterial pathogen Staphylococcus aureus

Rosado

Stapleton

Taylor

2006

57th International Astronautical Congress

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Extended manned space flight will result in a diminution of immune status and cause profound changes in the human bacterial microbiota, leading to increased risk of infection. Experiments conducted during short-term flight suggest that growth in microgravity leads to increases in bacterial antibiotic resistance and to cell wall changes. Growth under low-shear modelled microgravity (LSMMG) indicated that a reduced gravitational field acts as an environmental signal for expression of enhanced bacterial virulence in Gram-negative pathogens. We examined the effect of simulated microgravity on parameters of virulence in clinical isolates of Staphylococcus aureus. Three strains were grown under LSMMG in a High Aspect Ratio Vessel and compared with cells grown under normal gravity (NG) in the same vessel. There were no significant differences in the antibiotic susceptibility, growth rate or morphology of staphylococci grown under LSMMG compared to NG. LSMMGinduced reductions in synthesis of the pigment staphyloxanthin were noted. Strains secreted less protein under LSMMG and reductions in haemolysin secretion were found. Reduced expression of the major virulence determinant "-toxin in the microgravity environment was found by gene amplification. Thus, in contrast to published data on Gram-negative pathogens, simulated microgravity reduces the expression of key virulence determinants of S. aureus.

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Section: Resultscontrasting

confidence: 53%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of simulated microgravity on the virulence properties of the opportunistic bacterial pathogen Staphylococcus aureus

Rosado

Stapleton

Taylor

2006

57th International Astronautical Congress

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“…Beyond the outcomes described above indicating that bacteria generally tend to fare well in space in terms of reduced lag phase, increased population growth, and potentially enhanced secondary metabolite production, other experiments further suggest that the effectiveness of antibiotics against microorganisms may be reduced and microbial virulence may be increased (186,250). These factors, combined with the potential for immunosuppression suspected to occur in astronauts due to various spaceflight stressors, present increasing health-related concerns as human space missions become extended in duration and, more importantly, in distance from Earth (134).…”

Section: Applied Aspectsmentioning

confidence: 99%

Space Microbiology

Horneck

Klaus

Mancinelli

2010

Microbiol Mol Biol Rev

560

489

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SUMMARY The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis.

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“…MICs of E. coli, which were obtained from the commensal flora of an astronaut during the Salyut 7 Mission, and were isolated against both colistin and kanamycin increased significantly [7,8]. In addition, the Challenger experiments established that in-flight-cultivated E. coli ATCC 25992 grew more rapidly in subinhibitory concentrations of colistin than cells cultured in a terrestrial environment [9].…”

Section: Changes In Antibiotic Resistancementioning

confidence: 99%