spacetoday.net: Microgravity makes microbes more virulent

Posted: Wed, Sep 26, 2007, 1:48 PM ET (1748 GMT)
Exposing microbes to weightlessness makes them stronger and potentially more hazardous to humans, scientists reported. Researchers at Arizona State University flew a strain of the bacterium salmonella on the STS-115 shuttle mission last year, exposing them to microgravity conditions for 12 days. The scientists found that, when the bacteria returned, they were three times as likely to kill mice than salmonella bacteria that remained on Earth. The increase in virulence appears to be associated with the presence of a specific protein in the bacteria, which scientists said could allow doctors to develop countermeasures for future astronauts who spend long periods of time in weightlessness.