ISS microbes should be monitored to avoid threat to astronaut health

Enterobacter cloacae
Rough and smooth colony growth of Enterobacter cloacae bacteria on Tryptic Soy Broth agar. Credit: CDC

Strains of the bacterium Enterobacter, similar to newly found opportunistic infectious organisms seen in a few hospital settings, have been identified on the International Space Station (ISS). The strains found in space were not pathogenic to humans, but researchers believe they should be studied for potential health implications for future missions, according to a study published in the open access journal BMC Microbiology.

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.

Dr. Kasthuri Venkateswaran, Senior Research Scientist at the Jet Propulsion Laboratory Biotechnology and Planetary Protection Group and the corresponding author of the study said: "To show which species of the bacteria were present on the ISS, we used various methods to characterize their genomes in detail. We revealed that genomes of the five ISS Enterobacter strains were genetically most similar to three strains newly found on Earth. These three strains belonged to one species of the bacteria, called Enterobacter bugandensis, which had been found to cause disease in neonates and a compromised patient, who were admitted to three different hospitals (in east Africa, Washington state and Colorado)."

Comparing the genomes of the five ISS strains to the three clinical Earth strains allowed the authors to get a better understanding of whether the ISS strains showed characteristics of antimicrobial resistance, if they had gene profiles similar to those found in known multi-drug resistant bacteria, and to identify genes related to their ability to cause disease (pathogenic potential).

Dr. Nitin Singh, first author of the publication said: "Given the multi-drug resistance results for these ISS E. bugandensis genomes and the increased chance of pathogenicity we have identified, these species potentially pose important health considerations for future missions. However, it is important to understand that the strains found on the ISS were not virulent, which means they are not an active threat to human health, but something to be monitored."

The authors found that the ISS isolates had similar antimicrobial resistance patterns to the three clinical strains found on Earth and that they included 112 genes involved in virulence, disease and defense. While the ISS E. bugandensis were not pathogenic to humans, the authors predicted via computer analyses, a 79% probability that they may potentially cause disease. However, analyses in living organisms should be carried out to confirm this.

Dr. Venkateswaran said: "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."

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More information: Nitin K. Singh et al, Multi-drug resistant Enterobacter bugandensis species isolated from the International Space Station and comparative genomic analyses with human pathogenic strains, BMC Microbiology (2018). DOI: 10.1186/s12866-018-1325-2
Journal information: BMC Microbiology

Provided by BioMed Central
Citation: ISS microbes should be monitored to avoid threat to astronaut health (2018, November 22) retrieved 22 September 2019 from
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Nov 23, 2018
Hilarious to a very serious degree! (perhaps sirius degree?)

All the panspermia cargocultists and the children who want to play scientist in their garage altering micro-organisms and the nutjobs screeching about "chemtrails"

"We don't need no stinkin' alien bugs to exterminate us!"

We are causing the native diseases to mutate faster to assist us in our own suicidal errors of bad judgement.
Proof negative that "Big Brains" is a measure of intelligence or a capacity for wisdom.

And if any one of the woo loons start blathering that those ISS experiments are "proof" that Earthlife can survive and thrive in Space?

Just point out that those bugs are not being exposed to the full effect of UV/B, UV/C and even more lethal radiations.

Especially because they are safely cocooned away from vacuum, within the Magnetosphere.
With access to atmosphere and water.

Nov 24, 2018
What about the real bugs that live outside the viewing cupola windows that appear to thrive in the cold of space....and periodically have to be cleaned off the windows to allow better viewing out the windows:

""Well this is interesting: an article on CNET by Eric Mack, based on a Nov. 27 report from the Russian news agency TASS, discusses findings by Russian cosmonaut Anton Shkaplerov that "living bacteria from outer space" were found within samples collected during spacewalks several years ago (Shkaplerov was a member of Expedition 42 in November 2014.)

The samples were swabbed from outside surfaces of the International Space Station, including areas where engine fuel waste is expelled, and brought back to Earth for study. In addition to some terrestrial bacteria that were accidentally brought to the ISS via contaminated computer tablets, there were also living organisms found that "were absent during the launch of the ISS module.""

Nov 25, 2018
See, this is the kind of thing that the ISS was built to discover. Better to find this sort of thing and learn how to deal with it in low earth orbit, than halfway to mars or within a lunar colony.

Its comforting to know that science knows what it is doing.

Nov 25, 2018
Well, we could assume that this not outright fraud. Remember that the Russians originally claimed they had discovered Alien micro-organisms, Not originating on Earth from Earth Life.

We cannot blame the latest conclusions on Russian sloppy lab work. As NASA's embarrassing discovery of just how useless their clean room sterilization procedures have proven.

If it is verified that some Earth Life micro-organisms can survive on the outside of the ISS structure? It will take years to confirm if they can thrive outside.

In my, unverified, opinion. Where the outside samples were taken is a clue. Along the seals holding the view-ports in place. I'm betting there is undetected microscopic leakage from deteriorating materials. That allow the bugs access to escaping atmosphere and humidity from inside the structure. It's not like the little buggers need a whole lot to survive.

Plus, they are still protected from Solar and Cosmic radiation by the Magnetosphere.

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