Perhaps the most fascinating question to be addressed by AES-1 will be the role of the microgravity environment in potentially promoting antibiotic resistance, because bacteria are almost beyond gravity's grasp. "They're right on the threshold of being theoretically influenced by gravity directly," Klaus explained. "They're so small that Brownian motion [the random motion of tiny particles struck by atoms and molecules] is almost, but not quite dominant. If they were much bigger, gravity quickly becomes a dominant factor, and if they were much smaller, gravity becomes effectively lost in the noise. So these have made interesting models to work with. A virus is a little too small, but bacteria are right in a gray zone of neither being convective nor diffusive dominated."
Already a major problem on Earth, increasingly resistant bacterial strains can be an even greater threat for space travelers, because spaceflight can also compromise the astronaut's immune system. Couple that with bacteria's ability to grow better and resist antibiotics in space, and as Klaus noted, "that's not the right direction you want to have all those variables stacking up on you."
The hope is that a better understanding of how bacteria fight off drugs can lead to better ways to counter that resistance not only in space but back on Earth. The goal, Klaus said, is to "use the knowledge gained from observing and characterizing these interactions in the absence of gravity primarily for terrestrial benefit and secondarily for long-term astronaut crew health protection."
We will always be outnumbered by harmful species of bacteria, but we can still
|Contact: Laura Niles|
NASA/Johnson Space Center