Looks like the astronauts have been lucky so far, and in retrospect justifies the extremes of quarantine post-return (well, and pre-flight too) from missions:
http://www.technologyreview.com/Biotech/19425/ ...Salmonella grown onboard the space shuttle was many times deadlier than its terrestrial counterparts. The study suggests that NASA and other space agencies may need to worry that long manned missions will increase the virulence of microorganisms that astronauts inevitably carry with them. It has also given microbiologists insights into Salmonella that may lead to new therapies for infections on Earth. Researchers led by Cheryl Nickerson, associate professor at the Arizona State University Biodesign Institute, found that Salmonella grown during space-shuttle mission STS-115 in 2006 underwent major changes in the expression of 167 genes. When administered to mice back on Earth, the bacteria proved many times more deadly than an equivalent strain grown on the ground... ...[Those] bacteria grown in space displayed major changes in the activity of 167 genes and in the production of 73 proteins. Lower concentrations of the space bacteria caused lethal infections in mice, and the space bacteria killed more mice sooner than those grown on Earth. Nickerson says that these changes may be due to mechanical stresses that microgravity imposes on the bacterial cells. In microgravity, cells in a test tube or in our bodies are in a "state of buoyancy, floating suspended," she says. This changes the flow of fluids over the surfaces of the cells, and hence the cells' behavior.... Spaceflight also alters the genetic activity of human cells. "We evolved in a one-gravity environment," says Becker. "There are fundamental changes when you take gravity away." One study showed that spaceflight caused changes in the expression of more than 1,600 genes in human kidney cells grown in culture... ...The Arizona scientists provided evidence that one particular Salmonella gene regulates most of the molecular changes that the bacteria underwent. This global regulator, which seems to help the bacteria respond to stress by becoming more virulent, is a potential therapeutic target for future Salmonella treatments... [me] Now that could be quite something - a new target for antibacterial development is sorely needed, more or less desperately, depending on who you read. If this gene is present in other gram-negatives, it could be the basis for new classes of drugs/therapies. Of course, I'd be awfully surprised if some of the little buggers didn't work out a counter-measure. Debbi Andromeda Strain Maru ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/ _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
