Viruses and Bacteria Evolve Differently in Space.

Researchers studied T7 bacteriophages and E. coli on the International Space Station and found infections began more slowly and that both microbes developed unusual mutations under microgravity. The results were published in PLOS Biology.

Researchers studied how bacteriophages and Escherichia coli behaved aboard the International Space Station and compared those pairs to matched experiments on Earth. The experiments focused on the T7 phage and tracked infection timing and genetic changes. Microgravity alters fluid mixing and how cells encounter one another, conditions that can affect infection dynamics. The work was led by Vatsan Raman and published in PLOS Biology. Key observations: - T7 phages on the ISS took longer to begin infecting E. coli than the Earth-grown controls, a difference likely linked to altered fluid mixing under microgravity. - After infection, both the bacteria and the phages adapted rapidly, and many of the genetic changes seen in space differed from those on Earth. - Some mutations in the space phages appeared in genes not commonly altered in standard laboratory studies. - Follow-up experiments on Earth indicated several of the space-derived changes made phages better at infecting T7-resistant E. coli strains associated with urinary tract infections. - The authors emphasized that microgravity reshapes how phages and bacteria evolve together rather than only slowing infection processes. Summary: The study indicates microgravity can both delay initial phage infection and redirect the co-evolutionary paths of phages and bacteria, producing mutations not typically observed on Earth. Researchers now intend to identify the specific genes and mutations that emerged in T7 phages aboard the ISS and to examine how space alters more complex microbial communities.