Most people are aware that antibiotic-resistant superbugs are on the rise. In a snippet last year, I highlighted one important arm of the multipronged strategy to tackle antimicrobial resistance, namely surveillance (nice to see that the preprint I covered was published in The ISME Journal). Another important avenue involves alternative and complementary therapies, including bacteriophage therapies. Bacteriophages (phages, for short) are viruses that naturally hunt bacteria and were first used to cure bacterial infection in 1919. However, with the arrival of penicillin in the 1940s, phage therapy fell by the wayside (except in parts of the former Soviet Union, where access to antibiotic technology was limited during the Cold War). Interest in phage therapy is now resurging, but broader use is constrained by scientific, logistical, and regulatory challenges. Scientific challenges include the bacteria’s antiviral defences (which, it transpired recently, are much more extensive than we thought) and the emergence of phage-resistant bacteria during treatment.
A recent preprint presents new phages that may overcome these challenges, specifically for the bacterium Pseudomonas aeruginosa. P. aeruginosa can cause severe disease, including hospital-acquired infections, and poses a huge threat in terms of antibiotic resistance. The phages presented in the preprint not only killed bacteria but also impaired quorum sensing – the communication system used by bacterial populations to coordinate behaviours including phage defence. Importantly, the engineered phages improved survival of moth larvae infected with P. aeruginosa even when 10% of the bacterial population was resistant to phage-mediated killing. The clinical implications of this dual-action approach are tantalizing – the phages wouldn’t need to kill all the bacteria, because they also prevent bacterial communication, thus weakening the whole population. Any phage-resistant bacteria that remain could then more easily be finished off, e.g., by the immune system.
Of the antibiotic alternatives currently being explored, phage therapy is arguably the closest to changing how we treat infections. Research like that highlighted here will be important to overcome the remaining obstacles and offers hope in the face of the “silent pandemic”.
Anti-Quorum Sensing Phages Disarm Pseudomonas aeruginosa
In bioRxiv, February 2026
From the group of Nina Molin Høyland-Kroghsbo, University of Copenhagen, Denmark
Snippet by Katrina Woolcock
Image credit: Figure 3 (with permission) from Mauritzen et al cited above