ISS microgravity experiments reshape virus–bacteria evolution, hint at new tools against drug‑resistant superbugs

University of Wisconsin–Madison scientists report that experiments on the International Space Station show bacteriophages and E. coli evolve along markedly different genetic paths in microgravity than on Earth, changes that could be exploited to fight drug‑resistant infections. In paired tests, E. coli infected with phage T7 were incubated on Earth and aboard the ISS; after an initial slowdown, the phage successfully infected space‑grown bacteria, but sequencing revealed distinct mutations in both virus and host under near‑weightless conditions. Lead researchers Dr. Phil Huss and biochemist Srivatsan Raman say microgravity drove mutations in poorly understood regions of the phage genome rarely seen in ground experiments, while space‑grown E. coli acquired changes that appear to boost resistance and survival. Using deep mutational scanning on Earth, the team found that some microgravity‑linked mutations in T7’s receptor‑binding protein made the virus more effective at infecting E. coli strains normally resistant to T7, suggesting space‑shaped phages might be engineered as more potent antibacterial tools. The work underscores that microgravity is a fundamentally different evolutionary environment and bolsters a broader push to use space‑based research to understand and counter antimicrobial resistance, which public‑health agencies warn could kill millions globally in coming decades.