A research paper published in the journal Microbiome has unveiled that despite making efforts to keep spacecraft and cargo sterilized, viruses, bacteria and mold can travel along. In fact, dust particles aboard the ISS also have bacterial pathogens. These bacteria, viruses and pathogens can cause infections to astronauts in space.

Microorganisms that are harmless on earth can cause inflammation in space. Researchers have collected dust from air filter samples and vacuum bags used aboard the ISS. In space, dust and dirt do not settle as they do on earth. It keeps on floating in the zero gravity environment.

When astronauts are in space, his immune systems also become weak and they become vulnerable to infection. But NASA said that they ensure hygiene as the crew has to test air on regular basis, as well as water and surfaces.

There are first aid kits and specialized medical equipment at the ISS for astronauts if they fall sick there. In fact, crew has the training to handle basic medical situations and they can even consult doctors on ground.

In the most comprehensive hunt for bacteria and fungi ever done of the ISS, the team sequenced genetic material plucked from dust found in equipment that returned to Earth: an air filter used for 40 months and two used vacuum cleaner bags. The researchers compared DNA sequences derived from the ISS with vacuum bag dust collected over several months at two JPL clean rooms, which have about 50 people in them each day who inevitably leave behind bacteria.

“We need to know what we’re breathing in a closed environment,” says JPL microbiologist Kasthuri Venkateswaran, who led a collaboration that included investigators from two NASA space centers, three universities, and a biotech company.

As Venkateswaran and colleagues explain online today in Microbiome, they relied on state-of-the-art “deep-sequencing” machines, which are better able to assess diversity and abundance of organisms than traditional techniques.

The findings by NASA scientists could lead to a much stricter cleaning regime on board the space station if astronauts are to avoid spotty skin and other ailments.

The Space Station could also be infected with a strain of bacteria which could cause the deadly disease diptheria.

An analysis of dust collected from the artificial satellite found that Actinobacteria, a type of bacteria associated with human skin, made up a larger proportion of the microbial community in the ISS.

Now researchers have called for an urgent investigation to decide whether any of the bacteria could infect astronauts.

The study published in the journal Microbiome analysed the samples for microorganisms, and then stained their cells with a dye to determine whether they were living or dead.

If there is extreme situation then crew can make a comeback to earth. It is considered that if research is done to know in detail about how bacteria adapt to space travel then it could prove beneficial for astronauts traveling to space.