Drug-resistant bacteria—germs that have adapted immunities to antibiotic treatments—have found their way to the International Space Station, according to a new study.
Led by Nitin Singh, a microbiologist at NASA’s Jet Propulsion Laboratory, the study, published in BMC Microbiology, examined five strains of Enterobacter bacteria from samples collected in 2015 from the toilets and exercise equipment onboard the ISS.
Enterobacter is a common and mostly harmless bacterial family, but drug-resistant strains of the organism have been flagged in hospitals. A 2015 outbreak in a Tanzanian neonatal unit, for instance, caused blood infections in newborn babies.
Singh and his colleagues wanted to figure out the virulence of the Enterobacter strains on the ISS compared to antimicrobial-resistant pathogens on Earth. To do this, the team mapped the genomes of the space strains and compared them to the roughly 1,300 known Enterobacter genomes.
Their analysis revealed that the five strains were most genetically similar to Enterobacter bugandensis, the same drug-resistant species responsible for the Tanzania outbreak.
The finding corroborates a Nature paper from January that suggested E. bugandensis might be present on the space station. Singh’s team expanded beyond that research by evaluating the genetic virulence of the strains and their potential to infect the astronauts.