Astronauts leave many things when they go boldly. However, bacteria remain with them.
Extreme space travel can force these bacteria to increase their strength while reducing the immune system of the stressed, isolated crew. These effects ̵
Now researchers have taken another small step in the direction of space exploration by testing a new silver and ruthenium-based antimicrobial coating aboard the International Space Station (ISS). Published in Frontiers in Microbiology shows their study that the AGXX drastically reduced the number of bacteria on surfaces susceptible to contamination – and helped protect future astronauts outside the Moon and Mars.
A perfect storm
Microgravity. Cosmic Radiation. Psychological stress. Underground conditions at the ISS create a perfect storm of weakened immune systems and increased bacteria that can endanger the crew.
"Space flight can turn harmless bacteria into potential pathogens," says study author Prof. Elisabeth Grohmann from the Beuth University of Applied Sciences Berlin. "Just as stress hormones make astronauts susceptible to infection, the bacteria they transport become harder – they develop thick protective coatings and antibiotic resistance – and become more energetic, multiply and metabolize faster."
To make matters worse, the genes responsible for it are the cause New traits can be easily shared between different types of bacteria, either through direct contact or in the "matrix" of mucus they secrete – and so new villains in the agent Create -Smith Style To solve this problem, Grohmann and his colleagues tested a new anti-microbial coating, AGXX, on a contaminated surface aboard the ISS: the toilet door.
"AGXX contains both silver and ruthenium, which is conditioned by a vitamin derivative kills all types of bacteria as well as certain fungi, yeasts and viruses.The effect is similar to bleach – except that the coating is self-regenerating to keep it never consumed, "explains Grohmann.
Silver on o wn has been used since prehistory to prevent microbial growth. Today it can be found in all areas, from socks to swimming pools – which may have caused resistant bacteria. AGXX is one of the latest attempts to revive this ancient antimicrobial agent.
A glimmer of hope
The AGXX coating proved highly effective.
"After 6-month Exposure to the ISS No bacteria were recovered from AGXX-coated surfaces," reports Grohmann.
Already after 12 and 19 months, only 12 bacteria were recovered – an 80% reduction compared to bare ones Steel: A regular silver coating tested for comparison had only a slight antimicrobial effect and reduced the number of bacteria by 30% compared to steel.
"Prolonged exposure time resulted in some bacteria escaping antimicrobial activity. The antimicrobial test materials are static surfaces. where dead cells, dust particles and cell debris can accumulate over time and interfere with direct contact between the antimicrobial surface and the bacteria. "
Weathering Deep Space
" Most important is not a serious human Pathogens were found on every surface, so the infection risk for the ISS crew is currently low, "says Grohmann.
bacterial isolates form immunopotentiating mucous coatings, and most were resistant to at least three antibiotics, and they were also able to divide the responsible genes.
"Immunosuppression, bacterial virulence and thus the risk of infection increase with the duration of spaceflight. We need to develop new approaches to combating bacterial infections if we want to try longer missions to Mars and beyond, "concludes Grohmann.
" For our part, we continue to analyze AGXX's antimicrobial performance, most recently on board the joint isolation mission SIRIUS 18/9 from IBMP-NASA, continued. "
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Limits in Microbiology DOI: 10.3389 / fmicb.2019.00543, https://www.frontiersin.org/articles/10.3389/fmicb.2019.00543/full