Space Salmonella

Apparently, there were passengers other than astronauts aboard Space Shuttle STS-115 back in September 2006. Scientists sent along carefully packaged Salmonella (otherwise known as the cause of food poisoning) to learn about the affects of space travel on germs. Scientists consider this an important issue because wherever people travel, they bring microbes along with them. So whether we are traveling in a car, in an airplane, in space, or under the ocean, our microbes are our traveling companions.

Identical strains of Salmonella were used in the experiment conducted by scientists. The Salmonella which remained on Earth was kept under similar temperature conditions as the specimen sent into space. After the Shuttle returned, some of the mice were fed Salmonella that had remained on Earth, and others were fed the Shuttle Salmonella. The result of the experiment was that the mice who were fed the germ that had traveled through space became ill at three times the rate of the other mice, and they died more quickly. After observing the mice for twenty-five days, the scientists observed that 40% of the mice who had been given the Earth Salmonella were still alive, but only 10% of the mice given the Shuttle Salmonella were still alive. They also observed that only about one-third as much of the Shuttle Salmonella was required to kill the mice, as compared to the Earth Salmonella. Further examination revealed that 167 genes were altered in the Shuttle Salmonella.

Scientists speculate that the results of this experiment are caused by a force called "fluid shear", which refers to the force of liquid passing over cells. The Shuttle Salmonella experienced "microgravity", causing low fluid shear. The germs sensed this change in their environment and adapted their genetics. The scientists noted that the human gastrointestinal tract is also an area of low fluid shear, which may account for the ability of the Salmonella germ to so quickly debilitate its host.

The Space Shuttle Salmonella experiment yielded interesting results. Sending other germs into space to observe its affects on them may reveal new ways to combat contagious diseases.