A latest study from the NASA has found that the International Space Station is filled with bacteria and fungi. These bacteria include dangerous ones that are capable of causing illness among the residents. The fungi on the other hand could be damaging the station itself by corrosion find the researchers. The actual threat from these microbes is not yet known, they add. The results of the new study titled, “Characterization of the total and viable bacterial and fungal communities associated with the International Space Station surfaces,” were published in the latest issue of the journal Microbiome.
NASA Astronaut Terry Virts in the International Space Station. Image Credit: NASA
Astronauts Terry Virts and Jeffrey Williams were provided with several sterile wipes and were asked to swab eight specified surfaces of the station and send them back in sterile containers to the researchers. The swabs were taken on three different occasions during a 14 month period. Both high and low areas were covered including windows, exercise platforms, toilets, stowage racks, dining table and sleeping areas etc. The swabs were analyzed at the Jet Propulsion Laboratory of NASA in California. Results revealed that all types of bacteria and fungi grew on the surface of the station. They noted Staphylococcus, Enterobacteria, and Methylobacteria. The picture of microbes on ISS was similar to any home, office or other common human frequents in terms of microbial colonization, write the researchers.
The final results were;
- Staphylococcus (26 percent of total samples)
- Pantoea (23 percent)
- Bacillus (11 percent)
- Staphylococcus aureus (10 percent)
- Pantoea conspicua (9 percent)
- Pantoea gaviniae (9 percent)
- Rhodotorula mucilaginosa (main fungal growth)
The team explains that part of this was expected because humans have been living in the ISS for two decades now (since 1998). On the other hand their recovery of dangerous Staph bacteria from the ISS surfaces could point to something more sinister at play, they explain. These bacteria are commonly found in hospitals and similar places.
The team writes that astronauts have been visiting the ISS for a long time now. Around 227 astronauts have set foot on the ISS. Each time there might be transfer of microbes from earth. This study they explain would help them develop safety protocols for long-term space missions. There are several factors that allow these microbes to flourish. This includes ventilation, humidity, air pressure and lay out of the station, they add.
NASA JPL’s Checinska Sielaff and Camilla Urbaniak, in the study write, “Specific microbes in these indoor spaces have been shown to impact human health by influencing our susceptibility to allergies, infectious diseases, or sick building syndrome. The influence of the indoor microbiome on human health becomes more important for astronauts during flights due to altered immunity associated with space flight and the lack of sophisticated medical interventions that are available on Earth.”
Sielaff said in a statement, “Whether these opportunistic bacteria could cause disease in astronauts on the ISS is unknown. This would depend on a number of factors, including the health status of each individual and how these organisms function while in the space environment. Regardless, the detection of possible disease-causing organisms highlights the importance of further studies to examine how these ISS microbes function in space.”
The team explained that when these microbes for a biofilm or dangerous biological sheets of bacteria, they could cause harm. Kasthuri Venkateswaran, a senior research scientist at the JPL and co-author said, “Specific microbes in indoor spaces on Earth have been shown to impact human health. This is even more important for astronauts during spaceflight, as they have altered immunity and do not have access to the sophisticated medical interventions available on Earth.”
Dr Urbaniak added, “Some of the microorganisms we identified on the ISS have also been implicated in microbial induced corrosion on Earth. However, the role they play in corrosion aboard the ISS remains to be determined. In addition to understanding the possible impact of microbial and fungal organisms on astronaut health, understanding their potential impact on spacecraft will be important to maintain structural stability of the crew vehicle during long term space missions when routine indoor maintenance cannot be as easily performed.”
Microbes in space
Microbes survive in Mars-like environment finds study
Experts believe that if ISS in space could harbour bacteria and fungi from earth, other plants and the space can harbour life. An experiment called BIOMEX, for example was conducted by the German Aerospace Center (DLR). In this experiment the researchers exposed microbes (bacteria and fungi) and other microorganisms such as algae, lichens etc. to environments similar to Mars on a space station.
These microbes and microorganisms were place outside a space station called the Expose-R2 facility in a simulated Mars-like environment and soil. They were left there for 18 months between 2014 and 2016 and then brought back to the Earth for analysis. The results of the study were published in the journal Astrobiology.
Astrobiologist Jean-Pierre Paul de Vera of the DLR Institute of Planetary Research said that the results were surprising. De Vera added, “Some of the organisms and biomolecules showed tremendous resistance to radiation in outer space and actually returned to Earth as 'survivors' from space. Among other things, we studied archaea, which are unicellular microorganisms that have existed on Earth for over three-and-a-half billion years, living in salty seawater. Our 'test subjects' are relatives of theirs that have been isolated in the Arctic permafrost. They have survived in space conditions and are also detectable with our instruments. Such single-celled organisms could be candidates for life forms that might be found on Mars.”
De Vera added, “Of course, this does not mean that life actually exists on Mars. But the search for life is more than ever the strongest driving force for the next generation of missions to Mars.”
Antimicrobial coating on ISS toilets
The International Space Station is using a specially made silver- and ruthenium-based antimicrobial coating on their station’s toilets to keep microbes away especially on long term space missions.
Elisabeth Grohmann of Beuth University of Applied Sciences Berlin in a statement said, “Spaceflight can turn harmless bacteria into potential pathogens. 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.”
To control this problem the team of German and Russian scientists developed an antimicrobial coating called AGXX. It was developed by Largentec Vertriebs – a German company that calls it a “bioactive contact catalyst”. This coating is capable of inactivation of microbes and their killing through breaking of their cell walls by lysis.
Grohmann explained, “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.” They tested the coating on the bathroom door and found it extremely effective. Grohmann said, “After 6 months exposure on the ISS, no bacteria were recovered from AGXX-coated surfaces.” At 12 and 19 months of use, only 12 kinds of bacteria could be found. This is an 80 percent reduction from the normal steel doors, says the team.
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