Researchers at the University of Otago developed a CRISPR-based workflow to enable genome-wide mutagenesis of bacteriophages, creating a faster route to uncover essential genes and engineer phages for potential therapeutic use. The approach combines transposon insertion sequencing with CRISPR–anti-CRISPR selection to identify which phage genes can be disrupted without abolishing phage survival. The team reported that, beyond mapping gene function, the platform can insert new genetic cargo into phage genomes—potentially enabling modifications that help phages overcome bacterial defense systems. The work was published in Nature Microbiology, addressing a key bottleneck in phage biology where many genes remain functionally unknown. In the antimicrobial resistance race, the study’s relevance is that it supports more systematic engineering of phage therapeutics—moving beyond trial-and-error strain selection toward structured genetic design.