Bacteria use one alarm to detect two phage invaders.

Researchers led by Abel Garcia-Pino at Université Libre de Bruxelles and his collaborator Michael Laub (USA) have discovered that bacteria can use a single built-in alarm system to detect two very different viruses (phages). This clever trick helps bacteria defend themselves more efficiently and shows how smart their immune systems really are. The finding could help scientists better understand how bacteria and phages battle it out—and how we might use that in medicine.