Researchers have recently discovered that bacteria aboard the International Space Station (ISS) show a “shape-shifting” behavior.
What they observed is that the cell volume of the drugged bacteria decreased by 73 percent, while the number of cells multiplied 13-fold compared to those in a similar experiment on Earth.
The bacteria’s cell walls and outer membrane—called the envelope—became thicker, likely protecting the bacteria from the antibiotic.
Small capsules were also found forming outside some of the bacterial cell walls. These capsules, know as membrane vesicles, act as messengers between bacterial cells in a colony and can allow them to communicate and synchronize the start of the infection process.
Scientists have long observed that bacteria in space show a greater resistance to antibiotics compared to their earthly, gravity-bound counterparts, but they never directly linked the increased drug resistance to physical changes in the bacteria.
Unlike single-celled bacteria, which seem to do fairly well on the ISS, microgravity conditions weaken astronauts’ immune systems, increasing their risk of infection. Astronauts also suffer from loss of bone density, radiation poisoning, and eyesight degradation, among other symptoms.
In addition to its space applications, this experiment helps to understand how bacteria can become resistant to antibiotics on Earth, BioServe Director Louis Stodieck told CU Boulder Today.
“In space, for example, scientists can learn more about biochemical changes in various cells and organisms that the force of gravity on Earth may be masking.”
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