Antibiotic-Resistant Bacteria Found On International Space Station

NASA scientists have discovered the presence of antibiotic resistant bacteria on the International Space Station. The bacteria strains were found in the ISS's exercise area and toilet, according to a new study, though they aren't likely to harm the humans onboard. The bacterium Enterobacter's presence on the ISS is worrisome to officials, however, as a pathogenic variety could put the astronauts at risk.

A total of five strains were isolated from the ISS's exercise platform and space toilet during research on the bacteria living on the space station. Researchers with NASA JPL analyzed the five strains, comparing them with the genomes of more than a thousand Enterobacter strains on Earth.

All five had genetic similarities to three particular Earth strains belonging to the bacteria Enterobacter bugandensis, which could cause health issues for infants and individuals with compromised immune systems. The scientists found that the ISS's five strains aren't virulent, however, and therefore don't pose an active threat to human health.

Using a computer model, the team determined that the strains have a 79-percent probability of causing disease, but additional research on living animals will be necessary to determine whether this is the case. As well, researchers still need to determine the impact the ISS's space environment has on the bacteria.

The study concludes:

Given the MDR results for these ISS Enterobacter genomes and increased chance of pathogenicity (PathogenFinder algorithm with > 79% probability), these species pose important health considerations for future missions. Thorough genomic characterization of the strains isolated from ISS can help to understand the pathogenic potential, and inform future missions, but analyzing them in in-vivo systems is required to discern the influence of microgravity on their pathogenicity.