Research Summary

• During spaceflight, as well as on Earth, humans risk infection that is caused by bacteria.

• This investigation will examine gene and protein expression of Streptococcus pneumoniae (a bacteria that is normally found living in the human body) are effected by microgravity.

• Data from SPEGIS is anticipated to provide information on the threat of opportunistic pathogens in the space environment, which will assist in the development of diagnostic tools to monitor the atmosphere and surfaces (air, soil, and food) for the presence of these microbes.

Description

The Streptococcus pneumoniae Expression of Genes in Space (SPEGIS) will investigate S. pneumoniae gene expression and protein production in the space environment. S. pneumoniae is an important human pathogen and the leading cause of bacterial pneumonia (inflammation of the lungs with congestion), meningitis (inflammation of the membrane covering the brain and spinal cord), and otitis media (ear infection). Importantly, this pathogen has been isolated previously from the crew pre-flight and related bacteria are found in the spacecraft environment. Experiments will be performed to identify and characterize S. pneumoniae genes and proteins, which are differentially expressed in response to the space environment and compare microgravity-induced genes and proteins to those expressed during post-flight animal infection.

This experimental approach will result in new information about a significant human pathogen, add to our knowledge about the S. pneumoniae pathogenic mechanism, and also provide basic information on the bacterial model system of gene and protein expression in the space environment.

S. pneumoniae is a respiratory microbe that is normally found in the upper respiratory tract of approximately 40 percent of the healthy human population. The identification of specific S. pneumoniae virulence factors and cellular and molecular processes may aid scientists in furthering the understanding of how this bacteria causes infection. This data may aid in the design and development of new antimicrobial drugs.

Pre-flight the S. pneumoniae cultures will be grown on the ground in a laboratory environment and inoculated into Todd Hewitt Yeast extract (THY) growth medium for the flight experiment. The bacterial cultures will be loaded into the experiment containers approximately L-72 hours and will be launched at 4 degrees C in the Microgravity Environment Research Locker/INcubator (MERLIN).

Space Applications

Identification of the global genetic responses undergone by S. pneumoniae in reaction to space will enable this single-flight experiment to determine if the spacecraft environment exerts a selective pressure on microbial contaminants, leading to increased virulence and contributing to increased health risks to the crew. Results from SPEGIS will also provide information on the threat of opportunistic pathogens in the space environment, which will assist in the development of diagnostic tools to monitor the atmosphere and surfaces (air, soil, and food) for the presence of these microbes. Further, identification of spaceflight alterations to genes and proteins involved in bacterial proliferation and mutation will provide targets for pharmacological intervention, which will ultimately facilitate long-term exploration of the Moon and Mars.
Earth Applications

Analyzing and understanding the mechanisms utilized by S. pneumoniae to adapt to microgravity will likely lead to the development of novel methods to combat newly emerging drug-resistant strains, which could greatly assist in disease prevention and management on Earth.

Operational Requirements

Vials containing bacterial cultures will be loaded into the SPEGIS Canister Assembly. A total of three canisters will be flown on the space shuttle. Each Canister contains three 8 ml polypropylene vials. The vials are inserted into vial jackets to improve contact and enhance thermal transfer. The compression pad eliminates space between the vials and canister lid.
Operational Protocols

The SPEGIS payload will be launched while stored at +4 degrees C in the Microgravity Environment Research Locker/INcubator (MERLIN). After the orbiter docks with the ISS, the canisters will be transferred to the Minus Eighty Laboratory Freezer for ISS (MELFI) for +2 degrees C cold stowage. For the on-orbit incubation phase, the canisters will be transferred back to MERLIN and then incubated at +37.5 degrees C. After incubation, the canisters will be transferred back to MELFI for -95 degrees C cryopreservation. The samples will be returned to Earth while stored in the Double Coldbag with ICEPACs at -32 degrees C, which will maintain the integrity of the frozen samples for post-flight analysis by the investigator.

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