MAR 19, 2019 12:30 PM PDT

Combating Microbes on the International Space Station

WRITTEN BY: Carmen Leitch

While every effort is made to ensure that the stuff we send into space is free of Earthly contamination, microorganisms have been detected on the International Space Station (ISS). Researchers have been trying to learn more about how space changes these microbes; they seem to get tougher. They may pose a danger to the astronauts that have to share close quarters with them, especially because future missions may be very long and that astronauts have to stay healthy. Scientists are trying to make spaceflight safer, and have taken a small step in that direction.

The International Space Station / Credit: Pixabay

“Spaceflight can turn harmless bacteria into potential pathogens,” said the senior author of the work, Professor Elisabeth Grohmann of Beuth University of Applied Sciences Berlin. “Just as stress hormones leave astronauts vulnerable to infection, the bacteria they carry become hardier - developing thick protective coatings and resistance to antibiotics - and more vigorous, multiplying and metabolizing faster.”

A new antimicrobial coating that has a silver and ruthenium base was tested on the ISS. The coating, AGXX®, significantly reduced the amount of bacteria on surfaces that are likely to become contaminated. The findings, which may help improve missions to Mars, have been reported in Frontiers in Microbiology.

“AGXX® contains both silver and ruthenium, conditioned by a vitamin derivative, and it kills all kinds of bacteria as well as certain fungi, yeasts, and viruses. The effects are similar to bleach - except the coating is self-regenerating, so it never gets used up,” explained Grohmann.

Related: Space Bacteria are Adapting to Survive

The microbes onboard the ISS are subjected to myriad stressors, like cosmos radiation and microwaves. Those extraterrestrial conditions can cause the microbes to evolve, and microbes are usually able to share and spread genes around in a community easily. Learn more about the microbes found on the ISS from the video.

Since silver has been used for ages to prevent the growth of microbes, researchers employed it in the new AGXX® coating, which was tested on the door of the ISS toilet. It was found to be very effective. “After six months exposure on the ISS, no bacteria were recovered from AGXX®-coated surfaces,” said Grohmann.

When the researchers checked the surface after twelve and nineteen months, only twelve microbes were recovered; compared to bare steel, there was an eighty percent reduction. A coating of silver only had a mild effect, reducing the bacteria level by thirty percent compared to steel.

“With prolonged exposure time a few bacteria escaped the antimicrobial action. The antimicrobial test-materials are static surfaces, where dead cells, dust particles, and cell debris can accumulate over time and interfere with the direct contact between the antimicrobial surface and the bacteria,” noted Grohmann. “Most importantly, no serious human pathogens were found on any surface. Thus, the infection risk for the ISS crew currently is low.”

An assessment of the bacteria that was isolated showed that they could all form tough biofilms that can resist destruction, and many were resistant to at least three antimicrobials. 

“Immunosuppression, bacterial virulence and therefore infection risk increase with duration of spaceflight. We must continue to develop new approaches to combat bacterial infections if we are to attempt longer missions to Mars and beyond,” Grohmann added. “For our part, we are continuing to analyze the antimicrobial performance of AGXX®, most recently aboard the joint IBMP-NASA SIRIUS 18/9 isolation mission.”

Sources: AAAS/Eurekalert! Via Frontiers, Frontiers in Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
DEC 15, 2019
DEC 15, 2019
Potential Therapeutics for Nipah Virus Are Identified
The fatality rate of Nipah virus has an estimated range of 40 to 75 percent...
JAN 06, 2020
JAN 06, 2020
Microbes May Offset Some of the Negative Impacts of Ocean Microplastics
About 70 percent of the trash in the ocean is made of plastic. There is so much plastic in our oceans, it's thought to have entered our food chain....
JAN 19, 2020
Genetics & Genomics
JAN 19, 2020
Engineering Mosquitoes to Stop Dengue Virus Transmission
The dengue virus is transmitted by mosquitoes. It is found in over one hundred countries and threatens three billion people with a serious illness....
FEB 11, 2020
Clinical & Molecular DX
FEB 11, 2020
Portable device turns smartphones into diagnostic labs
Your smartphone lets you connect with friends, stores your memories, sends work emails and pays for your groceries. Soon, it could even help diagnose if yo...
FEB 05, 2020
FEB 05, 2020
Portable Device Detects Food-borne illness
 Foodborne illnesses kill 3,000 people on an annual basis. According to the Centers for Disease Control and Prevention, an estimated 48 million people...
FEB 18, 2020
FEB 18, 2020
Coronavirus Illness COVID-19 Has Now Caused Over 2,000 Deaths
The outbreak of COVID-19 disease caused by a novel coronavirus called SARS-CoV-2 has now claimed 2,005 lives and caused at least 75,079 cases....
Loading Comments...