Salmonella research conducted hundreds of miles off Earth's surface gave scientists the ability to alter the virulence of the pathogen, opening new doors to salmonella research and development.

The National Aeronautics and Space Administration, has sent two batches of salmonella to the International Space Station since 2006. The first trip revealed that the pathogen had become more virulent, or stronger, as a result of travel outside of Earth's atmosphere. The second experiment built on that, and revealed how the pathogen's growth can be manipulated.

"We basically have results about what genes turn on and off to get virulence," said Julie Robinson, program scientist for the space station at NASA's Johnson Space Center in Houston. "If you produce in ways that don't cause those genes to turn on, you may come up with better methods for processing or change the way we handle food preparation. I would say that anything is possible at this point."

NASA initiated the research to ensure the safety of food astronauts were eating in space, Robinson said. Once the initial samples came back with unexpected results, the research turned to how those results could be applied to the pathogen on Earth.

"It's not at all like the way we grow bugs on a lab bench," Robinson said, "and it may be the reason why people get so sick with salmonella. The space environment may be more similar to the environment in the digestive system."

Salmonella in space could change salmonella on Earth
                                                         Courtesy NASA

Astronaut Heidemarie M. Stefanyshyn-Piper, STS-126 mission specialist, works with the Microbe Group Activation Pack containing eight Fluid Processing Apparatuses on the middeck of Space Shuttle Endeavour while docked with the International Space Station.

After discovering the virulence change in 2006, NASA scientists, along with a research team at Arizona State University's Biodesign Institute, Tempe, adjusted the ion content in the bacteria's environment, creating different mediums to grow the bacteria. Scientists found the virulence didn't change in poor mediums, suggesting a connection between the bacteria and ion-rich or ion-poor environments.

"What it indicates about the ion pathway change is really suggestive," Robinson said. "You can control the environment of this bug to control virulence. So we've identified an environment that's allowed it to be more virulent, and figured out how to turn that off."

Robinson said a separate research team broke away and is focusing its efforts on developing a salmonella vaccine.

"Certainly the work in investigating this is barely beginning," Robinson said.

The original research was funded by NASA because of concern for crew members. Those research dollars were extended after the preliminary findings, Robinson said.

"The experiments have gotten additional research from NASA in order to understand this better as a more general objective," Robinson said.

The next round of research has not been announced yet, but another possibility for salmonella research in space, Robinson said, is through the National Institutes of Health, Bethesda, Md.

"They could make a proposition for space flight and use the space station as a lab," Robinson said.

The National Institutes of Health is also in the process of choosing its next research projects.