UC San Diego scientists say they have essentially put viruses through boot camp, enabling they to hunt down better and kill antibiotic-resistant Klebsiella pneumoniae, a notorious hospital superbug linked to pneumonia and sepsis. By using laboratory evolution, the team reshaped naturally occurring bacteriophages to target a wider range of bacterial strains, creating a potential backup plan for when standard antibiotics become ineffective.
As reported by UC San Diego Today, the work is led by David T. Pride, M.D., Ph.D., a professor of pathology at the UC San Diego School of Medicine. The university describes the process as “training” phages by allowing them and their bacterial targets to co-evolve in a controlled lab environment, then selecting the viral winners that cause the most damage.
Experimental Evolution: Letting Phages Learn
The peer-reviewed paper in Nature Communications details an experimental evolution setup where phages and Klebsiella were co-cultured for approximately 30 days. During that time, beneficial mutations could emerge and spread through the viral populations. Lab assays and genomic sequencing indicate that many of these changes occurred in genes that control how phages recognize and latch onto bacterial cells, which provides a molecular explanation for why the evolved viruses can infect more strains.
Broader Killing, Longer Suppression
According to news summaries and the team’s preprint, the lab‑evolved phages showed markedly broader host ranges. They were able to kill a variety of multidrug-resistant and extensively drug-resistant K. pneumoniae isolates and maintained bacterial growth suppression for longer periods in test tubes. Coverage by Phys.org and preprint servers highlights how the upgraded phages outperformed the ancestral strains from which they originated.
Why This Matters For Hospitals
Klebsiella pneumoniae is a leading cause of hospital‑acquired infections and can trigger severe pneumonia, bloodstream infections, and sepsis. The CDC classifies carbapenem‑resistant Enterobacterales, a group that includes resistant Klebsiella, as an urgent public‑health threat because they sharply limit treatment options and carry high mortality. That warning underscores why hospitals are hungry for new tools, as seen in the CDC.
Regulatory And Clinical Hurdles Remain
Turning lab-evolved phages into actual treatments will not be a quick process. The approach still has to clear safety testing, be produced under GMP manufacturing standards, and prove itself in clinical trials. Reviews of the field note that in the United States, most phage use has so far gone through single-patient investigational pathways and expanded-access program, while formal trial data and standardized production systems are still being developed. See analyses in Pharmaceuticals and in Frontiers in Cellular and Infection Microbiology for discussion of regulatory expectations and safety checks…