Bacteria on the International Space Station is adapting to survive the harsh environment rather than mutate into dangerous superbugs, a new study claims.
The findings are based on genomic analysis and show that bacteria are adapting to survive stressful conditions, rather than becoming antibiotic-resistant.
Bacteria found on board the International Space Station contained five strains with characteristics of drug resistance leading health officials to worry about viruses.
There has been speculation that the lack of ventilation, gravity and radiation exposition, could cause living organisms to become harmful.
But the new genetic evidence shows the bacteria are surviving, making it good news for any future manned missions to Mars.
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Bacteria on the International Space Station is adapting to survive the harsh environment rather than mutate into dangerous superbugs, a new study claims. Pictured here, the International Space Station photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking
The ISS houses thousands of different microbes, which have moved into space either on astronauts or in cargo.
Researchers, from Northwestern University in the US, are analyzing bacteria and compares the strains on the ISS with those on Earth.
They found that there is a lot of bacteria on Earth, they just responded, and perhaps evolved, to survive in a stressful environment.
There has been an increasing interest in understanding how microbes behave in enclosed environments as the idea of sending travelers to Mars becomes more of a reality.
Doctor Erica Hartmann, who led the study, acknowledged that microgravity and the lack of ventilation in space could affect living organisms, including bacteria.
'These are stressful, harsh conditions. Does the environment select for superbugs because they have an advantage? The answer appears to be 'no,' she said.
'People will be in little capsules where they can not open windows, go outside or circulate the air for long periods of time.
"We're genuinely concerned about how this could affect microbes."
The National Center for Biotechnology Information in the US maintains a publicly available database, containing the genomic analyzes or many of bacteria isolated from the ISS.
Dr Hartmann's team used that data to compare the strains of Staphylococcus aureus and Bacillus cereus on the ISS to those on Earth.
Found on human skin, S. aureus contains the tough-to-treat MRSA strain. B. cereus lives in soil and has fewer implications for human health.
Researchers analyzing bacteria and comparing the strains on the ISS bacteria are surviving, making it good news for any future manned mission to Mars. (stock image of E. coli in a plastic petri dish)
Dr Hartmann said: 'Bacteria that live on skin are very happy there.
'Your skin is warm and has certain oils and organic chemicals that bacteria really like.
'When you shed those bacteria, they find themselves living in a very different environment.
'A building's surface is cold and barren, which is extremely stressful for certain bacteria.'
HOW SPACE CAN MUTATE BUGS
One recent study in research in NPJ Microgravity found that one bacteria acquired well over a dozen mutations when exposed to space, and that these changes make it better at reproduction.
Astronauts on board the ISS have already encountered thick biofilms or bacteria on their equipment that are growing faster than normal.
To adapt to living on surfaces, the bacteria containing advantageous genes are selected for or they mutate.
For those living on the ISS, the researchers said that they helped to reduce stress, so that they could grow and function in a harsh environment.
Study first author Dr Ryan Blaustein, a postdoctoral fellow at Hartmann's lab, said: "Based on genomic analysis, it looks like bacteria are adapting to live, not evolving to cause disease.
'We did not see anything special about antibiotic resistance or virulence in the space station's bacteria.'
Although that is good news for astronauts and potential space tourists, the researchers were careful to point out that unhealthy people can still spread illness on space stations and space shuttles.
Dr Hartmann added: 'Everywhere you go, you bring your microbes with you.
'Astronauts are exceedingly healthy people. But as we talk about expanding space flight to tourists who do not necessarily meet astronaut criteria, we do not know what will happen.
'We can not say that if you put someone in a closed bubble in space that it will not transfer to other people. It's like when somebody gets sick, and everyone gets sick. "
The findings were published in the journal mSystems.
WHAT IS THE INTERNATIONAL SPACE STATION?
The International Space Station (ISS) is a $ 100 billion (£ 80 billion) science and engineering laboratory that orbits 250 miles (400 km) from above Earth.
It has been permanently staffed by rotating crews or astronauts and cosmonauts since November 2000.
Research conducted aboard the ISS often requires one or more of the unusual conditions present in low Earth orbit, such as low-gravity or oxygen.
The International Space Station is a $ 100 billion (£ 80 billion) science and engineering laboratory that orbits 250 miles (400 km) from Earth
ISS studies have investigated human research, space medicine, life sciences, physical sciences, astronomy and meteorology.
The US space agency, NASA, spends about $ 3 billion (£ 2.4 billion) a year on space program, a level of funding that is endorsed by the Trump administration and Congress.
A U.S. House of Representatives committee that oversees Nasa has begun looking at whether to extend the program beyond 2024.
Alternatively, the money could be used to speed up human space initiatives to the moon and Mars.