Study indicates bacteria-fighting viruses have potential to reduce antibiotic resistance

A new study published in the journal Cell Host Microbe furthered research on the effectiveness of phage therapy and what antibiotics can be successfully combined with it, in an effort to reduce antibiotic resistance.

The study was conducted by the University of Exeter and led by Tatiana Dimitiru, PhD. In an experiment, researchers exposed Pseudomonas aeruginosa, a bacterium that causes disease in people with cystic fibrosis and other immunocompromised conditions, to eight different antibiotics. Four of the antibiotics were bacteriostatic, which slow cell growth without killing them. Scientists then observed whether bacteria fought off the viruses through receptor mutation, which decreases disease severity, or use of their CRISPR-Cas adaptive immune systems.

After three days post-infection, the level of phage resistance was similar among every culture. However, researchers found that how the bacteria resisted the phage differed and was largely dependent on which antibiotic was used on it. Results showed bacteriostatic antibiotics significantly increased the level of CRISPR-based immunity which slowed phage development and cleared the viral infection.

Scientists concluded that the rate of phage replication plays an integral role in the CRISPR-Cas immune system’s ability to fight off phage infection. These results offer new evidence on which combinations of antibiotic can be used to with phage therapy to effectively treat infection, moving medicine one step closer to reducing antibiotic resistance.