A scientific journey decades in the making has found a new antibiotic strategy to defeat gram-negative bacteria like Salmonella, Pseudomonas and E. coli, the culprits in many urinary tract infections. The synthetic molecule works fast and is durable. It interferes with synthesis of the bacterial outer membrane by jamming an enzyme. When tested against a clinical collection of 285 bacterial strains, including some that were highly resistant to commercial antibiotics, it killed them all.