In Space No One Can Hear You Sneeze
The greatest threat to space travel may be the common cold
In what could be the premise of a horror sci-fi movie, scientists have discovered that bacteria shape-shift. In experiments on board the International Space Station (ISS), they found that E. coli adapts so it is harder to kill with antibiotics. The discovery potentially poses a big problem for space travel: On long-duration missions, we will need antibiotics to treat sick astronauts. But if bacteria are able to quickly develop resistance to them, common infections could become deadly in space.
Scientists have known for some time that bacteria behave differently in space compared with how they do on Earth—it takes higher concentrations of antibiotics to kill them, for example. The exact reason for this, however, is unknown. That’s why a team of researchers led by Luis Zea from the University of Colorado, Boulder, sent E.
coli samples up to the ISS to compare how the bacterium grew and responded to the antibiotic gentamicin sulfate, which kills it on Earth. Their findings, published in the journal Frontiers in Microbiology, showed that bacteria cells became significantly smaller, while their numbers vastly increased, when compared with samples on Earth.
The space samples also developed a thicker cell wall and membrane, which the team believes helped the bacterium protect itself from the antibiotic.
Another finding was that the space E. coli formed in clumps more than it does on Earth, which the scientists suggest is a defensive maneuver to sacrifice the outer cells to protect the inner ones. This may be related to the formation of biofilms, multicellular communities that build up on surfaces over time. While not necessarily dangerous, if bacteria form as a biofilm on part of a space station, they could end up infecting astronauts on board.
“By default, bacteria will accompany humans in our exploration of space,” the researchers write. Included within our microbiome are opportunistic pathogens, which do not cause disease in healthy people but can cause infection when an immune system is compromised.
Because immune suppression is known to occur during spaceflight, the study findings are particularly concerning. As a result, the authors say, further research will be needed to assess the risk posed to astronauts on longduration missions.
In the meantime, astronauts should pack a hankie.