Bacteria on the ISS have mutated, but not become dangerous
Bacteria on the International Space Station are growing and mutating in the space environment - but according to new research, they don't appear to pose a threat to humans.
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International Space Station. Photo: NASA |
This is good news for astronauts, as some previous studies have expressed concerns about the risk that the space environment will cause some strains of bacteria to mutate in a more toxic direction.
“There has been a lot of research on the effects of radiation, microgravity, and lack of air on living organisms, including bacteria,” said Erica Hartmann, a professor of biology at Northwestern University in Miami, Florida. Leading scientists have long wondered whether space travel could accelerate the evolution of bacteria into “superbugs.”
Based on the results of the new study, published on January 8 in the journal mSystems, the answer appears to be “no,” according to Professor Hartmann.
In the study, scientists analyzed DNA from two types of bacteria: Staphylococcus aureus (found on the skin, often causing staph infections) and Bacillus cereus (found in the digestive systems of animals as well as soil and mud, and is usually harmless). Both bacteria were collected from the environment around the space station. The results showed that although these bacteria had mutated differently from the original strain on Earth, they did not find any obvious genetic traits of “superbugs” (so-called because they are resistant to most antibiotics).
On Earth, researchers say, when bacteria leave the human body (which is quite often), they mutate to adapt to their new environment. But in the cramped compartments of a spacecraft, there are concerns that months of exposure to such mutant bacteria could be hazardous to astronauts’ health.
However, it appears that the bacteria's mutations to adapt to space did not create any unusual factors that made them more contagious or more difficult to treat.
This would mean one less medical concern for long-term space travel. While NASA’s rigorous protocols have helped to minimize the risk of infectious diseases, there is still a risk that the lack of gravity could weaken our immune systems.
Apollo 7 astronaut Wally Schirra caught a cold during the mission, despite the crew being carefully screened and quarantined for a week before the mission. The possibility of an outbreak in a closed spacecraft remains to be seen.
