Could superbugs on the International Space Station mutate into a new breed of ‘supercharged’ killer?
- Five strains of Enterobacter were found in the ISS’s toilet and exercise area
- Previous studies have shown that when exposed to conditions in space, bacterial mutation can become ‘supercharged’ as they adapt to their new environment
Researchers who discovered superbugs were living aboard the International Space Station have called for urgent research into how space affects their development.
Scientists at NASA discovered that five different varieties of Enterobacter were found in the ISS’s toilet and exercise area.
Previous studies have shown that when exposed to conditions in space, bacterial mutation can become ‘supercharged’ as they adapt to their new environment.
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Scientists at NASA have discovered that five different varieties Enterobacter, a bug similar to that found in hospitals, have been found infesting the International Space Station
HOW SPACE CAN MUTATE BUGS
One recent study in research in NPJ Microgravity found that one bacteria acquired well over a dozen mutations when exposed to space, and that these changes make it better at reproduction.
Astronauts on board the ISS have already encountered thick biofilms of bacteria on their equipment that are growing faster than normal.
NASA experts have called for urgent research into the bugs.
‘Given the multi-drug resistance results for these ISS genomes and the increased chance of pathogenicity we have identified, these species potentially pose important health considerations for future missions,’ said Dr. Nitin Singh, first author of the paper.
‘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.’
However, according to computer modelling, there is a 79 per cent probability that they will develop into a human pathogen, and cause disease.
On Earth, some strains of Enterobacter can infect immunocompromised patients in intensive care wards – and they have high resistance to antibiotics.
The JPL researchers compared their antibiotic resistance to that of the three clinical strains, and found that the space Enterobacter were resistant to cefazolin, cefoxitin, oxacillin, penicillin and rifampin, and had varying degrees of resistance to others.
They also found that, while the space station Enterobacter strains aren’t currently human-pathogenic, they have 112 genes in common with the clinical strains, associated with virulence, disease and defense.
Microbiologists with NASA’s Jet Propulsion Laboratory regularly analyse microbe samples collected from the space station to see if the space environment affects their populations in any way – and also to see if they are posing a hazard either to the health of the astronauts, or the delicate equipment.
‘To show which species of the bacteria were present on the ISS, we used various methods to characterise 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,’ said microbioligist Kasthuri Venkateswaran.
‘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).’
The samples were collected in 2015.
‘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,’ Venkateswaran said.
‘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.’