Bacteriophage Therapy: Emerging Solutions for Antibiotic Resistance

Evolved bacteriophages adapted in vitro at the University of California San Diego reportedly expand host range and improve killing of multidrug‑resistant Klebsiella pneumoniae in laboratory studies.

The study involved an experimental‑evolution strategy in which phages were co‑cultured with diverse clinical K. pneumoniae strains across multiple passages to select for increased infectivity. Genetic changes focused on receptor‑binding genes and were proposed as a mechanism for the efficacy gains.

The evolved phages produced higher bacterial kill rates, broader host‑range expansion, and more durable suppression of regrowth versus baseline phages and standard antibiotics on key in vitro endpoints. By contrast, several multidrug‑resistant isolates showed limited susceptibility to antibiotics while evolved phages retained lytic activity in laboratory assays.