The International Space Station (ISS), an example of international cooperation in the field of space research – it was born as a result of a historic agreement signed twenty-five years ago by Bill Clinton and Boris Yeltsin – has just turned twenty. Two decades of very successful operations and also, of course, unexpected incidents.
The scientific journal BMC Microbiology has just published a study carried out by scientists from NASA’s Jet Propulsion Laboratory (JPL) on five small tenants that have been found on the ISS : they are strains of Enterobacter bacteria, similar to newly discovered infectious organisms in selected hospital settings, which were isolated from the space toilet and exercise platform in March 2015, as part of a larger effort to characterize bacterial communities that live on surfaces within of the space station.
According to this research, these strains have not been pathogenic to humans so far , but the researchers do believe that they should be further studied for their possible impact on future missions.
With the aim of identifying these Enterobacter species and knowing in detail the genetic makeup of the individual strains, the scientists carried out a comparison of their genomes with those available from 1,291 Enterobacter strains collected on Earth. “To determine in detail which species of bacteria were present on the ISS, we used various methods to characterize their genomes,” explains Kasthuri Venkateswaran, a research scientist at JPL’s Planetary Biotechnology and Protection Group and one of the study’s authors.
Genetically similar to ‘Enterobacter bugandensis’
In the end, he explains, they came to the conclusion that the genomes of these five strains were genetically very similar to three newly found on our planet and that they belong to a species of bacteria called Enterobacter bugandensis that has made newborns and people sick with fragile health.
By comparing the genomes of the five ISS strains with the three clinical strains on Earth, the authors were able to better understand whether the former exhibited antimicrobial resistance characteristics, whether they exhibited genetic profiles similar to those found in multidrug-resistant bacteria, and identify genes related to their ability to cause disease (pathogenic potential). According to a computer analysis, although these E. bugandensis have not been pathogenic for humans , there is a 79% chance that they potentially cause disease. Although, to confirm this, tests must first be performed on living organisms.
Likewise, Venkateswaran explains in this regard that the possibility that “an opportunistic pathogen such as E. bugandensis may or may not cause disease and how much threat it poses depends on a variety of factors, including environmental ones . Further in vivo studies are needed to discern the impact. that conditions on the ISS, such as microgravity and other issues related to space and spacecraft, can have on pathogenicity and virulence “, concludes the scientist.
Image: NASA
