Astronauts on the International Space Station (ISS) have found a way to minimize the spread of germs on the station

Space can be a risky environment for humans especially since it can weaken the body and activate viruses. The zero-gravity environment is also conducive for microbes to grow stronger and more resistant to antibiotics. Fortunately, astronauts on the ISS found a way to stop microbes from spreading through a new substance called "AgXX."

Its antimicrobial coating is made of silver and ruthenium. ISS astronauts applied the substance on the dirtiest surfaces like the toilet door. During the 19-month test, the AgXX kept the coated surface bacteria-free. However, the surface did not stay germ-free after another six months. Nine strains of bacteria penetrated the surface but this did not indicate that the material was less effective.

The germ-killing capabilities of the coating went down because the surface became more conducive for bacteria. Dust and dirt accumulated on the surface and made it friendlier to the strains.

According to Elisabeth Grohmann, a microbiologist at Beuth University of Applied Sciences Berlin and lead author of the new study, AgXX works like bleach. It can kill all types of bacteria, including certain types of viruses, yeasts and fungi. However, bleach never gets used up because it is self-generating.

The researchers did not find serious human pathogens like vancomycin-resistant Enterococci (VRE) or methicillin-resistant Staphylococcus aureus (MRSA). There was low infection risk among the crew. Grohman did suggest that spaceflight is capable of turning harmless bacteria into potential pathogens.

This is true as NASA recently found that certain dormant viruses like herpes get activated during spaceflight. While the astronauts showed only a few of the symptoms, there is no telling if the risk of prolonged space expeditions like those to the Moon and Mars can do serious harm to humans aboard. Scientists noted that spaceflight increases the secretion of stress hormones like cortisol and adrenaline. These hormones can affect or suppress the immune system which can put astronauts at risk.

"Immunosuppression, bacterial virulence and therefore infection risk increases with duration of spaceflight," Grohmann said. She added that there should be the continued development of ways to fight bacterial infections if there are plans of launching longer missions.