"A box full of viruses and bacteria has completed its return trip to the International Space Station," reports ScienceAlert, "and the changes these 'bugs' experienced in their travels could help us Earthlings tackle drug-resistant infections..." Scientists aboard the space station incubated different combinations of bacteria and phages for 25 days, while the research team led by biochemist Vatsan Raman carried out the same experiments in Madison, down here on Earth. "Space fundamentally changes how phages and bacteria interact: infection is slowed, and both organisms evolve along a different trajectory than they do on Earth," the researchers explain. In the weightlessness of space, bacteria acquired mutations in genes involved in the microbe's stress response and nutrient management. Their surface proteins also changed. After a slow start, the phages mutated in response, so they could continue binding to their victims.

The team found that certain space-specific phage mutations were especially effective at killing Earth-bound bacteria responsible for urinary tract infections (UTIs). More than 90 percent of the bacteria responsible for UTIs are antibiotic-resistant, making phage treatments a promising alternative.