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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1997

Secondary metabolism in simulated microgravity: beta-lactam production by Streptomyces clavuligerus

Rotating bioreactors designed at NASA's Johnson Space Center were used to simulate a microgravity environment in which to study secondary metabolism. The system examined was beta-lactam antibiotic production by Streptomyces clavuligerus. Both growth and beta-lactam production occurred in simulated microgravity. Stimulatory effects of phosphate and L-lysine, previously detected in normal gravity, also occurred in simulated microgravity. The degree of beta-lactam antibiotic production was markedly inhibited by simulated microgravity.

NASA Discipline Environmental Health↗
NASA NTRS2010

Preliminary Evaluation of Commercial Off the Shelf (COTS) Packing Materials for Flight Medication Dispenser (FMD) Technology Development

With the advent of longer duration space missions, pharmaceutical use in space has increased. During the first 33 space shuttle missions, crew members took more than 500 individual doses of 31 different medications . Anecdotal reports from crew members described medications as generally "well tolerated" and "effective". However, reported use of increased medication doses and discrepancies in ground vs. flight efficacy may result from reduced potency or altered bioavailability due to changes in chemical and/or physical parameters of pharmaceutical stability. Based on preliminary results from a ground-based irradiation and an inflight study on pharmaceutical stability, three susceptible medications, Amoxicillin/Clavulanate and Sulfamethoxazole/trimethoprim antibiotics tablets and promethazine (PMZ), an antihistamine were selected for testing using two types of Oliver-Tolas bags, TPC-1475(Clear) and TPF-0599B (Foil) for radiation Shielding effectiveness. The material composition of the bags included aluminum coated Mylar sheathing coated with multifunctional nanocomposities based on polyethylene with dispersed boron-rich nanophases. Two bags of each medication were irradiated for different time intervals with 14.6 rad/min to achieve 0.1 Gy, 1 Gy and 10 Gy of cumulative radiation dose. Active pharmaceutical content (API) in each medication was determined and results analyzed. No significant difference in API content was observed between control and irradiated samples for both antibiotic tablets suggesting both types of bags may offer protection against gamma radiation; results with PMZ were inconclusive. These preliminary results suggest that Oliver-Tolas TPL-1475 and TPF-0599B materials may possess characteristics suitable for protection against ionizing radiation and can be considered for designing and further testing of FMD technology.

Du, Brian↗
NASA NTRS2011

Low Fluid Shear Culture of Staphylococcus Aureus Represses hfq Expression and Induces an Attachment-Independent Biofilm Phenotype

Background: The opportunistic pathogen, Staphylococcus aureus, experiences fluctuations in fluid shear during infection and colonization of a human host. Colonization frequently occurs at mucus membrane sites such as in the gastrointestinal tract where the bacterium may experience low levels of fluid shear. The response of S. aureus to low fluid shear remains unclear. Methods: S. aureus was cultured to stationary phase using Rotating-Wall Vessel (RWV) bioreactors which produce a physiologically relevant low fluid shear environment. The bacterial aggregates that developed in the RWV were evaluated by electron microscopy as well as for antibiotic resistance and other virulence-associated stressors. Genetic expression profiles for the low-shear cultured S. aureus were determined by microarray analysis and quantitative real-time PCR. Results: Planktonic S. aureus cultures in the low-shear environment formed aggregates completely encased in high amounts of extracellular polymeric substances. In addition, these aggregates demonstrated increased antibiotic resistance indicating attachment-independent biofilm formation. Carotenoid production in the low-shear cultured S. aureus was significantly decreased, and these cultures displayed an increased susceptibility to oxidative stress and killing by whole blood. The hfq gene, associated with low-shear growth in Gram negative organisms, was also found to be down-regulated in S. aureus. Conclusions: Collectively, this data suggests that S. aureus decreases virulence characteristics in favor of a biofilm-dwelling colonization phenotype in response to a low fluid shear environment. Furthermore, the identification of an Hfq response to low-shear culture in S. aureus, in addition to the previously reported responses in Gram negative organisms, strongly suggests an evolutionarily conserved response to mechanical stimuli among structurally diverse prokaryotes.

Ott, C. Mark↗
NASA NTRS2016

Payload Hardware and Experimental Protocol for Testing the Effect of Space Microgravity on the Resistance to Gentamicin of Stationary-Phase Uropathogenic Escherichia Coli and Its Sigma (sup S)-Deficient Mutant

Human immune response is compromised and bacteria can become more antibiotic resistant in space microgravity (MG). We report that under low-shear modeled microgravity (LSMMG) stationary-phase uropathogenic Escherichia coli (UPEC) become more resistant to gentamicin (Gm). UPEC causes urinary tract infections (UTIs), reported to afflict astronauts; Gm is a standard treatment, so these findings could impact astronaut health. Because LSMMG has been shown to differ from MG, we report here preparations to examine UPEC's Gm sensitivity during spaceflight using the E. coli Anti-Microbial Satellite (EcAMSat) on a free flying nanosatellite in low Earth orbit. Within EcAMSats payload, a 48-microwell fluidic card contains and supports study of bacterial cultures at constant temperature; optical absorbance changes in cell suspensions are made at three wavelengths for each microwell and a fluid-delivery system provides growth medium and predefined Gm concentrations. Performance characterization is reported for spaceflight prototypes of this payload system. Using conventional microtiter plates, we show that Alamar Blue (AB) absorbance changes due to cellular metabolism accurately reflect E. coli viability changes: measuring AB absorbance onboard EcAMSat will enable telemetry of spaceflight data to Earth. Laboratory results using payload prototypes are consistent with wellplate and flask findings of differential sensitivity of UPEC and its delta rpoS strain to Gm. Space MG studies using EcAMSat should clarify inconsistencies from previous space experiments on bacterial antibiotic sensitivity. Further, if sigma (sup s) plays the same role in space MG as in LSMMG and Earth gravity, EcAMSat results would facilitate utilizing our previously developed terrestrial UTI countermeasures in astronauts.

Matin, A. C.↗
NASA NTRS2001

Induction of microcin B17 formation in Escherichia coli ZK650 by limitation of oxygen and glucose is independent of glucose consumption rate

We examined the consumption of glucose from the media in which Escherichia coli ZK650 was grown. This organism, which produces the polypeptide antibiotic microcin B17 best under conditions of limiting supplies of glucose and air, was grown with a low level of glucose (0.5 mg/ml) as well as a high level (5.0 mg/ml) under both high and low aeration. Glucose consumption rates were virtually identical under both high and low aeration. Thus, glucose consumption rate is not a regulating factor in microcin B17 formation.

NASA Discipline Cell Biology↗
NASA NTRS2014

E. coli AntiMicrobial Satellite (EcAMSat)

The E. coli AntiMicrobial Satellite(EcAMSat) mission will investigate space microgravity affects on the antibiotic resistance of E. coli, a bacterial pathogen responsible for urinary tract infection in humans and animals. EcAMSat is being developed through a partnership between NASA Ames Research Center and the Stanford University School of Medicine. Scientists believe that the results of this experiment could help design effective countermeasures to protect astronauts health during long duration human space missions.

e. Coli↗
NASA NTRS2019

The Effects of Low-Shear Simulated Microgravity on Soil Bacterium Pantoea Agglomerans

As NASA's effort to establish a permanent residence in space continues, research on the effects of microgravity onbiological microorganisms is vital to protect or promote the health of plants and their astronaut counterparts. The purpose of this study is to determine the effects of microgravity on Pantoea agglomerans (P. agglomerans), using an analog microgravity simulator; the Rotary Cell Culture System (RCCS) developed at Johnson Space Center (JSC) in Houston, TX. P. agglomerans has been shown to be a plant growth promoter (PGPR) in ground based studies, but has also been shown to be a pathogen in both plants and immunocompromised patients. In this study, we will determine changes in the growth rate and antibiotic susceptibility of P. agglomerans when exposed to simulated microgravity.

HARV↗
NASA NTRS1972

Urological considerations in space medicine.

Urological problems encountered during the preparation phases of Biosatellite III, flight of Bonny the Space Monkey, are detailed. The solution to each problem is detailed. The catheter system employed, antibiotic coverage used, and bacteria encountered in the urine of the five animals are detailed. Urinary calcium levels in three ground based animals are illustrated. Testicular alterations encountered in all animals are mentioned. It is concluded that space flights of duration beyond nine days may present serious problems of a urological nature.

Cockett, A. T. K.↗
NASA NTRS1972

Mass spectrometry.

Review of the current state of mass spectrometry, indicating its unique importance for advanced scientific research. Mass spectrometry applications in computer techniques, gas chromatography, ion cyclotron resonance, molecular fragmentation and ionization, and isotope labeling are covered. Details are given on mass spectrometry applications in bio-organic chemistry and biomedical research. As the subjects of these applications are indicated alkaloids, carbohydrates, lipids, terpenes, quinones, nucleic acid components, peptides, antibiotics, and human and animal metabolisms. Particular attention is given to the mass spectra of organo-inorganic compounds, inorganic mass spectrometry, surface phenomena such as secondary ion and electron emission, and elemental and isotope analysis. Further topics include mass spectrometry in organic geochemistry, applications in geochronology and cosmochemistry, and organic mass spectrometry.

Burlingame, A. L.↗
NASA NTRS1973

Study for identification of beneficial uses of Space, phase 1. Volume 2, book 2: Technical report: results, conclusions and recommendations

A variety of technologies were investigated to determine the benefits to be derived from space activities. The subjects accepted for product development are: (1) eutectics for cold cathodes, (2) higher putiry fiber optics, (3) fluidic wafers, (4) large germanium wafers for gamma ray camera, (5) improved batteries and capacitors, (6) optical filters, (7) corrosion resistant electrodes, (8) high strength carbon-based filaments for plastic reinforcement, and (9) new antibiotics. In addition, three ideas for services, involving disposal of radioactive wastes, blood analysis, and enhanced solar insolation were proposed.

Source record↗
NASA NTRS1974

Membrane permeability and the loss of germination factor from Neurospora crassa at low water activities

Neurospora crassa conidia incubating in buffer at low water activities release a germination-essential component as well as 260-nm absorbing and ninhydrin-positive materials, regardless of whether an electrolyte or nonelectrolyte is used to reduce water activity. Chloroform and antibiotics known to increase cell-membrane permeability have a similar effect. This suggests that membrane damage occurs in media of low water activity and that an increase in permeability is responsible for the release of cellular components. The damage caused in media of low water activity is nonlethal in most cases, and the conidia recover when transferred to nutrient medium.

Charlang, G.↗
NASA NTRS1975

A rapid method for the determination of microbial susceptibility using the firefly luciferase assay for adenosine triphosphate (ATP)

Luciferase assay for adenosine triphosphate (ATP) was optimized for pure bacteria in broth in order to evaluate if changes in bacterial ATP content could be used as a rapid measure of antibiotic effect on microorganisms. Broth cultures of log phase bacteria were incubated at 310 K (37 C) for 2.5 hours at antimicrobial concentrations which resulted in the best discrimination between sensitive and resistant strains. Eighty-seven strains of 11 bacterial species were studied for their susceptibility to 12 commonly used antimicrobial agents: ampicillin, Penicillin G, nafcillin, carbenicillin, cephalothin, tetracycline, erythromycin, clindamycin, gentamicin, nitrofurantoin, colistin, and chloramplenicol. The major advantage of the ATP system over existing methods of rapid microbial susceptibility testing is that the assay can be made specific for bacterial ATP.

Vellend, H.↗
NASA NTRS1976

Increased concentration of Pseudomonas aeruginosa and Staphylococcus sp. in small animals exposed to aerospace environments

The effects of increased concentrations of PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS in the total bacterial flora of small animals exposed to simulated spacecraft environments were evaluated. Tests to detect changes in infectivity, effects of antibiotic treatments, immune responses to bacterial antigens, and effectiveness of immune responses in the experimental environment were conducted. The most significant results appear to be the differences in immune responses at simulated altitudes and the production of infection in the presence of a specific antibody.

Guthrie, R. K.↗
NASA NTRS1976

Sequence characterization of 5S ribosomal RNA from eight gram positive procaryotes

Complete nucleotide sequences are presented for 5S rRNA from Bacillus subtilis, B. firmus, B. pasteurii, B. brevis, Lactobacillus brevis, and Streptococcus faecalis, and 5S rRNA oligonucleotide catalogs and partial sequence data are given for B. cereus and Sporosarcina ureae. These data demonstrate a striking consistency of 5S rRNA primary and secondary structure within a given bacterial grouping. An exception is B. brevis, in which the 5S rRNA sequence varies significantly from that of other bacilli in the tuned helix and the procaryotic loop. The localization of these variations suggests that B. brevis occupies an ecological niche that selects such changes. It is noted that this organism produces antibiotics which affect ribosome function.

Woese, C. R.↗
NASA NTRS1976

Microbial load monitor

A card configuration which combines the functions of identification, enumeration and antibiotic sensitivity into one card was developed. An instrument package was designed around the card to integrate the card filling, incubation reading, computation and decision making process into one compact unit. Support equipment was also designed to prepare the expandable material used in the MLM.

Holen, J. T.↗
NASA NTRS1978

Methods for microbiological and immunological studies of space flight crews

Systematic laboratory procedures compiled as an outgrowth of a joint U.S./U.S.S.R. microbiological-immunological experiment performed during the Apollo-Soyuz Test Project space flight are presented. Included are mutually compatible methods for the identification of aerobic and microaerophilic bacteria, yeast and yeastlike microorganisms, and filamentous fungi; methods for the bacteriophage typing of Staphylococcus aureus; and methods for determining the sensitivity of S. aureus to antibiotics. Immunological methods using blood and immunological and biochemical methods using salivary parotid fluid are also described. Formulas for media and laboratory reagents used are listed.

Taylor, G. R.↗