Whole-genome sequencing is revolutionizing bacterial outbreak investigation, but its application to the clinic remains limited. In 2020, prospective and retrospective surveillance detected a Pseudomonas aeruginosa outbreak with 253 isolates collected from 82 patients in 26 wards of a hospital. Its origin was dated to the late 1990s, just after the facility opened, and patient-to-patient and environment-to-patient cases of transmission were inferred. Over time, two epidemic subclones evolved i...
