A National Institute of Health paper released in March has identified previously unseen and unknown variants of a bacterium known for being multi-drug resistant, have been isolated from the ISS.
Thirteen strains of Enterobacter bugandensis, have mutated and became genetically distinct compared to their Earth counterparts. The study also found that E. bugandensis coexisted with multiple other microorganisms, and in some cases could have helped those organisms survive. So far, NASA, Roscosmos, or any other international partners aboard the ISS have not reported infected astronauts or, worse, transmission of the species from the ISS to Earth.
A NASA news release this week perhaps states the findings more clearly:
“In a new scientific paper funded by an Ames Space Biology grant, Principal Investigator Dr. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory strains of the bacterial species Enterobacter bugandensis isolated from the International Space Station (ISS) were studied. Thirteen strains of E. bugandensis, a bacterium notorious for being multi-drug resistant, were isolated from the ISS. Study findings indicate under stress, the ISS isolated strains were mutated and became genetically and functionally distinct compared to their Earth counterparts. The strains were able to viably persist in the ISS over time with a significant abundance. E. bugandensis coexisted with multiple other microorganisms, and in some cases could have helped those organisms survive.
“Closed human-built environments, such as the ISS, are unique areas that provide an extreme environment subject to microgravity, radiation, and elevated carbon dioxide levels. Any microorganisms introduced to these areas must adapt to thrive. By delving into microbial dynamics in extreme environments, this research opens doors to effective preventative measure for astronaut health.”
Multi-Drug Resistant Bacteria Found on ISS Mutating to Become Functionally Distinct (NASA)
In short, this common species from Earth has traveled to ISS, adapted to the unique environment of the orbiting outpost, and has evolved into something entirely new that is resistant to standard antibiotic treatments.
Known Since 2015
The recently released study backs up other studies that go back as far as 2015. According to a peer-reviewed release in 2018, “Researchers at the Jet Propulsion Laboratory, California Institute of Technology, USA investigated five strains of Enterobacter that were isolated from the space toilet and the exercise platform on the ISS in March 2015 as part of a wider effort to characterize the bacterial communities that live on surfaces inside the space station. To identify the species of Enterobacter collected on the ISS and to show in detail the genetic make-up of the individual strains, the researchers compared the ISS strains to all publicly available genomes of 1,291 Enterobacter strains collected on Earth.”
In 2018, Dr Kasthuri Venkateswaran, a Senior Research Scientist at the Jet Propulsion Laboratory Biotechnology and Planetary Protection Group stated that, “Whether or not an opportunistic pathogen like E. bugandensis causes disease and how much of a threat it is, 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, other space, and spacecraft-related factors, may have on pathogenicity and virulence.”
Health Effects of E. bugandensis?
According to the NIH’s National Center for Biotechnology Information, “Enterobacter species are responsible for causing many nosocomial infections, and less commonly community-acquired infections, including urinary tract infections (UTI), respiratory infections, soft tissue infections, osteomyelitis, and endocarditis, among many others.”
Again, no illnesses specific to E. bugandensis have been reported, but scientists have been monitoring this situation for some time.
