Fforget Ridley Scott’s Alien. There could be a real horror story in space. As one national newspaper headline warned, the International Space Station ‘filled with germs‘.
But should such a revelation really make us scream? The story stems from a new NASA study (reported in Microbiome) that found that some bacterial pathogens, including Actinobacteria – which often accompanies human skin – thrive in the station, 248 miles above the earth. Not that it’s necessarily a bad thing. A more equal microbiological newspaper under my editors would have adapted the headline to read ‘Microbiologists are not surprised that the International Space Station is filled with microorganisms’.
Because it’s time to get something right. The press tends to think that all bacteria are germs. But it is not. Germs are synonymous with diseases, but most bacteria do not cause diseases, they are essential for life on earth, which drives nutrient cycles and prevents elements and nutrients from being permanently locked up and unavailable. Without bacteria, the earth would not function properly and we would become an arid planet. This is now a horror story.
Microbes are everywhere
Microbes (bacteria, viruses, fungi and protozoa) are everywhere – and in large numbers. They show wide diversity and thrive where it is hospitable while colonizing areas we would not possibly think of, such as hot springs, in the middle of salt crystals and at the bottom of the deepest oceans.
The human body carries 20 times more bacterial cells than human cells, and we, like the environment, will suffer if we are microbiologically sterile. Bacteria in our intestines process food, protect us from invading germs, and also boost and strengthen our immune systems.
When descending an escalator, simply move your finger along the surfaces. The black dirt is mainly human cells and associated bacteria. People shed millions of cells a day. Indeed, trailing dogs follow specific human scents that are deposited by skins in the environment. Just keep in mind that a fully clothed person can lay down enough cells for a dog to detect them more than 72 hours later.
But what does this have to do with ISS and NASA? Let’s just say that no microbiologist would be surprised or worried to hear that NASA has found that the ISS is filled with microbes (including some ‘germs’ or bacteria that cause disease). It is a closed unit, it has oxygen and is filled with people shedding skin and bacteria.
They also need to perform bodily functions, and even in a perfect world, toilet habits are less than spotless. Fecal material, which also carries a large amount of bacteria, can be introduced.
Canny klein colonist
The personnel on ISS are therefore probably the main source of pollution, although some bacteria may have been introduced as far as the construction of parts on earth.
NASA seeks to understand how the overall bacterial diversity and profile changes over time and also its impact on its personnel. As NASA said, “Understanding the nature of the microbial communities – the microbiome – in the station is key to managing astronauts’ health and equipment maintenance.”
After all, the ISS, like other spacecraft, is a closed community. Nothing blows through the window – if it does, bacteria will be the least worried about the crew – and this environment only changes occasionally during the irregular staff changes, when new astronauts come on board their own different microbial communities. NASA wants to better understand this and how it could affect future missions.
Time for a spring clean?
So should the astronauts spend a little more time cleaning up? Is there a little vacuuming? A little dusting and polishing?
Well, they probably do anyway. The air is filtered and there are few reports of infections hitting the crew. Despite the headlines evoking a picture of a soup of bacteria filling the ISS, infection is relatively rare.
A comparison over a period of three years showed that a large percentage of medical events were physical problems. Space adaptation syndrome and nervous system problems accounted for 50% of all medical events with infectious diseases that make up only 1.4% of such problems.
Astronauts further reduce the possibility of infection by periods of quarantine before their mission. NASA is rightly concerned that infections could be transmitted to anyone in such a closed environment.
This NASA study is an important investigation because it relates to the understanding of the factors that ensure the disease-free status and well-being of current and future ISS crews, where help is not immediately available and prevention is better than a drug.
Infectious diseases are only one of the medical factors that can affect the astronauts’ health, as they have other non-microbiological influences to deal with. Before them, life with microbes is probably just another much-needed reminder of home. When they come home, with their immune systems suitable for the ISS microbial environment, they may be more susceptible to challenges exposed to the wider range of infectious agents on Earth.
This article was published from The Conversation under a Creative Commons license.