Antibiotic Effectiveness in Space-1 (AES-1) - 12.07.16
Antibiotic Effectiveness in Space-1 (AES-1) examines cultures of Escherichia coli (E. coli) bacteria to investigate the reduced effectiveness of antibiotics in microgravity. Understanding how bacteria withstand large amounts of antibiotics improves methods to reduce infection risks during space missions. Additionally, drug-resistant bacteria cause 2 million infections and 23,000 deaths in the U.S. each year. Understanding how some bacteria grow in the presence of antibiotics may lead to new treatments that benefit patients on Earth. Science Results for Everyone
Information Pending Experiment Details
OpNom: NLP-Vaccine 21
David M. Klaus, Ph.D., BioServe Space Technologies, Boulder, CO, United States
Shawn Levy, Ph.D., Hudson Alpha Institute for Biotechnology, Huntsville, AL, United States
Louis S. Stodieck, Ph.D., University of Colorado, BioServe Space Technologies, Boulder, CO, United States
BioServe Space Technologies, University of Colorado, Boulder, CO, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
National Laboratory (NL)
Scientific Discovery, Space Exploration, Earth Benefits
ISS Expedition Duration
September 2013 - March 2015
- Antibiotic Effectiveness in Space-1 (AES-1) evaluates the effectiveness of antibiotics against bacteria grown in the space flight environment.
- When the Escherichia coli (E. coli) bacterial cultures are undergoing exponential growth, various concentrations of known antibiotics are introduced. After being exposed to the antibiotics for approximately 12-24 hours, the experiment is stopped by introducing fixatives into the cultures.
- Bacteria in space that are still able to grow at what would be normally inhibitory concentrations of the antibiotic on the ground are brought back to Earth and assessed for alterations in gene expression and changes in shape and structure that might explain their ability to survive in the spaceflight environment.
Antibiotic Effectiveness in Space-1(AES-1) evaluates the effectiveness of antibiotics against bacteria grown in the space flight environment. Group Activation Packs (GAPs) containing eight Fluids Processing Apparatuses (FPAs) are used to process the bacterial samples. Specifically, once on orbit, the GAP hardware is operated so as to inoculate nutrient rich media with Escherichia coli (E. coli) bacterial cultures. When the bacteria are undergoing exponential growth, various concentrations of known antibiotics including Gentamicin Sulfate and Colistin Sulfate are introduced. After being exposed to the antibiotics for approximately 12-24 hours, half of the samples are preserved by introducing RNAlater® II (a preservative) into the cultures and half of the samples are fixed by introducing paraformaldehyde (fixative). Bacteria in space that are still able to grow at what would be normally inhibitory concentrations of the antibiotic on the ground are brought back to Earth and assessed for alterations in gene expression and changes in shape and structure that might explain their ability to survive in the space flight environment. This work may lead to a greater understanding of antibiotic efficacy and more effective treatment of infectious disease world-wide.
Cultures of Escherichia coli (E. coli) bacteria are grown in a nutrient-rich broth on the International Space Station, and as they multiply, crewmembers add various concentrations of antibiotics. The cultures are chemically preserved after 12-24 hours so they can be returned to Earth for analysis. Understanding changes in the bacteria’s shape, structure and gene expression provides insight into how they are able to thrive in space flight environments. This leads to more effective methods for preventing infection on future space missions.
Several species of bacteria are evolving to resist treatment with common antibiotics, leading to millions of infections and costly hospitalizations each year. Improved understanding of the molecular mechanisms for antibiotic resistance in certain bacteria leads to more effective treatments.
Operational Requirements and Protocols
Decadal Survey Recommendations
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Bacteria grown in space exhibit a number of different behaviors such as reduced lag phase, higher growth (probably as an adaptive response to periodic starvation), enhanced biofilm formation, increased virulence, and reduced susceptibility to antibiotics compared to how they behave on Earth. These changes have been attributed to reduced material flow surrounding cells, where movement of molecules consumed and excreted by the cell is limited to diffusion in the absence of gravity-assisted flow. Molecular genetic data from this experiment, with E. coli exposed to the antibiotic Gentamicin Sulfate, support this hypothesis and show an overexpression of genes associated with starvation, the search for alternative energy sources, increased metabolism, enhanced acetate production, and other systematic responses to acidity all of which can be associated with reduced extracellular mass transport. When nutrient concentration decreases, bacterial cells devote more of their limited resources to making more protein needed to broaden the search for alternative sources of carbon (a primary nutrient), even if these are unavailable. Genes associated with making energy from glucose were activated in space, indicating an overall stimulation of metabolic activity. Collectively, the enhanced growth condition explanation suggested to occur as a result of the proposed altered environmental factors in microgravity is further supported by the new gene expression data. Future studies could include the exhaustive investigation of the transport proteins, and also their genes, of all potential sources of carbon to specifically investigate this phenomenon.^ back to top
Zea L, Prasad N, Levy SE, Stodieck LS, Jones A, Shrestha S, Klaus DM. A molecular genetic basis explaining altered bacterial behavior in space. PLOS ONE. 2016 November 2; 11(11): e0164359. DOI: 10.1371/journal.pone.0164359.
Ground Based Results Publications
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