Scientists observed viruses attacking bacteria in space, and the results were bizarre. The International Space Station (ISS) is a unique environment, and research has revealed that bacteriophages, the viruses that prey on bacteria, exhibit peculiar behavior in space. Scientists studied the interaction between bacteriophages and Escherichia coli bacteria aboard the ISS, comparing them to pairs grown on Earth. The space-dwelling phages took longer to infect their hosts, and both the bacteria and viruses developed unusual mutations in response to each other and the microgravity conditions of the ISS. The findings suggest that phages in space could develop mutations beneficial to humans on Earth. Microbes continue to evolve under microgravity, and this evolution is not always predictable from Earth-based experiments, according to senior study author Vatsan Raman. Phage infection is highly dependent on transport, encounter rates, and host physiology, all of which can change in space. The study focused on a particular phage that loves to munch on E. coli, known as T7. The ISS phages were slower to infect their prey initially, likely due to the different fluid mixing under microgravity. However, once infection occurred, both the phages and bacteria rapidly adapted, often very differently from their Earth counterparts. The bacteria evolved to boost their defenses against phage infection and enhance their survivability in space, while the phages evolved to more easily infect E. coli. Some genetic changes in space phages were unlike anything seen on Earth. The main takeaway is that microgravity doesn't just delay phage infection; it reshapes how phages and bacteria evolve together. The study's findings have implications for space travel, especially longer-duration missions. The microbes living aboard the ISS and future space stations could evolve in ways that impact astronaut health and the environment. Despite the scary possibility, space phages could also benefit humanity. The team's experiments on Earth found that some changes in space made the phages better at attacking T7-resistant strains of E. coli that cause urinary tract infections. Phages are being developed as an alternative treatment for drug-resistant infections. While impractical to run these experiments on the ISS, understanding how microgravity shapes microbial evolution could help scientists apply those lessons to Earth-based studies.
