Why the International Space Station is riddled with bacteria

FRidley Scott’s orget Alien. There can be an actual horror story in space. As a national newspaper headline warned, the International Space Station is’full of germs“.

But should such a revelation really make us scream? The story stems from a new NASA study (reported in Microbiome) which found that certain bacterial pathogens, including actinobacteria – often associated with human skin – thrive in the station, 248 miles above Earth. Not that this is necessarily a bad thing. A more balanced microbiological journal under my leadership would have changed the title to read it “ Microbiologists are not surprised that the International Space Station is filled with microorganisms ”.

Because it’s time to get the ball rolling. The press tends to think of all bacteria as germs. But they are not. Germs are synonymous with disease, but the majority of bacteria do not cause disease, they are essential to life on earth, causing nutrient cycles and preventing elements and nutrients from being permanently locked away and unavailable. Without bacteria, the Earth would not function properly and we would become a barren planet. It’s a horror story.

Germs are everywhere

Microbes (bacteria, viruses, fungi and protozoa) are everywhere – and in great numbers. They show great diversity and thrive where it’s hospitable while also colonizing areas we wouldn’t have thought possible, like hot springs, amid salt crystals, and deep in the deepest oceans.

The human body contains 20 times more bacterial cells than human cells, and we and the environment would suffer if we were microbiologically sterile. Bacteria in our guts process food, protect us from invasive germs, and also stimulate and strengthen our immune systems, making them stronger.

When you get off a subway escalator, just run your finger along surfaces. This black gunk is mostly made up of human cells and associated bacteria. Humans shed millions of cells a day. This is because dogs that hang out follow specific human scents emitted by skin cells excreted into the environment. Just consider that a fully clothed person can deposit enough cells for a dog to track them over 72 hours later.

But what does this have to do with the ISS and NASA? Well, let’s just say that no microbiologist would be surprised or alarmed to learn that NASA has discovered that the ISS is full of microbes (including a few “germs” or bacteria that cause disease). It’s a closed unit, it contains oxygen, and it’s filled with people who kill skin and bacteria.

They also have to perform bodily functions, and even in a perfect world, grooming habits are far from flawless. Faeces, which also carry a large number of bacteria, may be introduced.

Canny little settlers

The ISS personnel are therefore probably the main source of contamination, although some bacteria may have been introduced as early as the construction of sections on Earth.

NASA seeks to understand how total bacterial diversity and profile changes over time and its effects on its staff as well. As NASA put it, “Understanding the nature of the communities of microbes – the microbiome – in the station is essential for managing the health of astronauts and the maintenance of equipment.”

After all, the ISS, like other spacecraft, is a closed community. Nothing blows out the window – if it did, bacteria would be the least of the crew’s worries – and this environment only changes occasionally during rare personnel changes, when new astronauts embark their own microbial communities. distinct. NASA is looking to better understand this and how it might affect future missions.

Time for a spring cleaning?

So should astronauts spend a little more time cleaning? Do some vacuuming? A bit of dusting and polishing?

Well, they probably do anyway. Their air is filtered and there are few reports of infections affecting the crew. Despite the headlines that conjure up the image of a soup of bacteria filling the ISS, infection among the crew is relatively rare.

A comparison over a three-year period showed that a high proportion of medical events were physical problems. Spatial adaptation syndrome and nervous system problems accounted for 50% of all medical events with infectious diseases accounting for only 1.4% of these problems.

Astronauts further reduce the possibility of infection through pre-mission quarantine periods. NASA is rightly concerned that infections could be spread to everyone in such a closed environment.

This NASA study is an important piece of research because it concerns understanding the factors that ensure the disease-free status and well-being of current and future ISS crews, where help is not immediately available. at hand and prevention is better than cure.

Infectious diseases are just one of the medical factors that can affect the health of astronauts as they have other non-microbiological influences to contend with. Indeed, for them, living with germs is probably just another essential reminder from home. However, coming home, with their immune systems optimized for the ISS’s microbial environment, could make them more vulnerable to the challenges posed by exposure to the widest range of infectious agents on Earth.

This article is republished from The Conversation under a Creative Commons license.