Bacteria from Earth can easily colonize Mars : SCIENCE : Tech Times http://www.techtimes.com/articles/6480/20140504/bacteria-earth-easily-colonize-mars.htm
Beating Bacteria on Earth and in Space
By sheer strength of numbers, bacteria are by far the most successful life form on Earth. As we've learned over the past several decades of human spaceflight, they don't do too badly in microgravity either. For evidence, just look back on the astronauts and cosmonauts who were stricken with infections during their flights. At home, we have long-established and usually effective antibiotic treatments against most harmful bacteria. But previous studies have shown that in space, bacteria can survive and thrive in what would be fatal drug concentrations for them back on Earth. How is that possible?
That's a question of vital concern not just today, with International Space Station crews living together in confined spaces for months at a time, but for the future astronauts who will embark on long-duration missions to Mars and beyond. For those journeys, a quick emergency return to Earth won't be possible. Searching for the answer also helps researchers to understand the inner workings of bacteria as they seek to develop improved treatments for patients on the ground and in space.
The Antibiotic Effectiveness in Space (AES-1) investigation, scheduled to launch in January aboard the first contracted Orbital resupply flight to the space station, is a systematic attempt to probe the reasons for antibiotic resistance in space. "Is the mechanism that's allowing this to occur some form of adaptation or drug resistance acquisition within the cell, or is it more of an indirect function of the biophysical environment, the changes due to microgravity and mass transport?" asked AES-1 principal investigator David Klaus, Ph.D., of BioServe Space Technologies at the University of Colorado in Boulder.
The AES-1 investigation consists of 32 separate combinations of E. coli bacteria and various concentrations of a common antibiotic drug, either Gentamicin and Colistin. That experimental set is duplicated four times to provide a total of 128 separate data points for analysis. Upon return, researchers will check the samples for bacterial population growth. The samples will also be subjected to gene expression examinations by BioServe's study partner, HudsonAlpha Institute for Biotechnology in Huntsville, Ala.
"The idea with this first round is to determine whether the cells actually grow in what should be an inhibitory level of drug, and if so, are there any correlations with specific changes in the gene expression?" Klaus explained. Part of the AES-1 package will return to Earth with the SpaceX-3 mission in February 2014, with the remainder coming back on SpaceX-4 in the summer.
While AES-1 won't be too labor-intensive in flight, it does require a certain degree of participation by the station crew. "A few days into the mission, they'll go in and activate the 16 different group activation packs, and then periodically per the timeline they'll do a termination step on them," said Klaus. "We've flown various forms of our payload, sometimes essentially completely autonomous and sometimes with direct crew interaction."
BioServe is familiar with this type of design flexibility, with experience on 43 prior missions since 1991, including sounding rockets, Mir, space shuttle and space station flights. "You essentially begin to trade off experimental volume for automation. The more automation you have, the less [experiment volume] you can generally accommodate because of the need for the electronics and supporting systems," said Klaus.
Although Klaus and the research team plan to fly other bacterial species on future AES investigations, they decided E. coli was the best choice for this first flight. "We would ultimately like to fly things that are more clinically relevant, but for this first round, because they're so well characterized and we in BioServe have flown a lot of previous work using E. coli, it made sense to stick with this primary line we've been using for a number of years," Klaus noted. "We're going to hopefully answer the question fairly definitively in this case of whether they really are able to grow in these normally lethal levels of drugs. That's first and foremost, to repeat what's been seen in the past, but do so in a more systematic way and with a larger dataset."
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 prevail by maintaining and improving our arsenal of antibiotic weapons. The AES-1 investigation promises to be an important step in that quest, whether we encounter our bacterial foes on Earth, in orbit, or on future distant space voyages.
Mark Wolverton
(International Space Station Program Science Office)
Bacteria from Earth Could Quickly Colonize Mars
Bacteria from Earth could quickly colonize the surface of Mars, according to new research conducted aboard the International Space Station (ISS).
Research into bacterial colonization on the red planet was not part of the plan to terraform the alien world ahead of human occupation. Instead, three teams investigated how to prevent microbes from Earth from hitching a ride to the red planet aboard spacecraft.
It is nearly impossible to remove all biological contaminants from equipment headed to other planets. By better understanding what organisms can survive in space or on the surfaces of other worlds, mission planners can learn which forms of microscopic life to concentrate on during the sanitation process.
"If you are able to reduce the numbers to acceptable levels, a proxy for cleanliness, the assumption is that the life forms will not survive under harsh space conditions," Kasthuri Venkateswaran of the Jet Propulsion Laboratory and co-author of all three papers, said.
Researchers investigated the problem using independent experiments. The first used the EXPOSE-E facility aboard the ISS. The team then proceeded to expose organisms known to be hardy on Earth to 18 months in space.
"It was found that some... are also partially resistant to the even more hostile environment of outer space, including high vacuum, temperature fluctuation, the full spectrum of extraterrestrial solar electromagnetic radiation, and cosmic ionizing radiation," a group of international researchers wrote.
A second team, composed of researchers from the German Aerospace Center, California Institute of Technology and Jet Propulsion Laboratory exposed bacteria to space conditions, also for a year and a half. They used the European Technology Exposure Facility (EuTEF) on the space station to conduct their experiment.
"After 18 months of exposure... under dark space conditions... spores showed 10-40% survivability, whereas a survival rate of 85-100% was observed when these spores were kept aboard the ISS under dark simulated martian atmospheric conditions," the team reported.
When bacteria of the Firmicute phylum come under stress, they can form protective shells, called endospores. These coatings protect the organisms from harm from extreme environmental conditions like droughts. Biologists wanted to know if these structures could protect bacteria from sanitation processes and the harsh environment of space.
A team from Germany, France and the United States subjected bacteria to conditions similar to those expected on a trip to, and on the surface of, Mars. Only ultraviolet light was proven to be effective at killing the organisms.
"All other environmental parameters encountered by the 'trip to Mars' or 'stay on Mars' spores did little harm to the spores, which showed about 50% survival or more. The data demonstrate the high chance of survival of spores on a Mars mission, if protected against solar irradiation," the investigators wrote in the article announcing their results.
The investigations of interplanetary microbe contamination were all published together in the Astrobiology Journal.
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