Magazine article Science News

Bugs in Space: Genes Explain Why Salmonella Grow Deadlier When Freed from Earth's Gravity

Magazine article Science News

Bugs in Space: Genes Explain Why Salmonella Grow Deadlier When Freed from Earth's Gravity

Article excerpt

Bacteria that flew in a space shuttle overtook their earthbound counterparts in toxicity. The finding could have implications not only for protecting astronauts from sickness as spaceflights become longer and more frequent but also for understanding bacteria on Earth.

Previous experiments using a spaceflight stimulator had hinted that bacteria might grow more virulent in the absence of gravity. To see whether real space flight would produce a similar result, a team led by Cheryl Nickerson of Arizona State University in Tempe sent samples of Salmonella typhimurium, a leading cause of food poisoning, into orbit on the Space Shuttle Atlantis in September 2006. The bacteria grew in closed tubes, and shuttle crew members tended to them--controlling their temperature, for example, or adding nutrients. Meanwhile, scientists on the ground mirrored the astronauts' procedures on cultures kept in a room designed to reproduce conditions on the shuttle. The only difference: gravity.

When the space shuttle landed, the scientists compared the two sets of pathogens by testing their effects on mice. They found that animals injected with S. typhimurium that had traveled to space died faster than those injected with bacteria that hadn't made the trip.

To explore this difference in virulence, the team analyzed what genes were active in each group of bacteria.

The researchers found that 167 genes showed more than twofold differences in activity, either higher or lower, between bacteria grown in the shuttle and those grown on Earth. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.