Designing P. aeruginosa synthetic phages with reduced genomes

In the era where antibiotic resistance is considered one of the major worldwide concerns, bacteriophages have emerged as a promising therapeutic approach to deal with this problem. Genetically engineered bacteriophages can enable enhanced anti-bacterial functionalities, but require cloning additional genes into the phage genomes, which might be challenging due to the DNA encapsulation capacity of a phage. To tackle this issue, we designed and assembled for the first time synthetic phages with smaller genomes by knocking out up to 48% of the genes encoding hypothetical proteins from the genome of the newly isolated Pseudomonas aeruginosa phage vB_PaeP_PE3. The antibacterial efficacy of the wild-type and the synthetic phages was assessed in vitro as well as in vivo using a Galleria mellonella infection model. Overall, both in vitro and in vivo studies revealed that the knock-outs made in phage genome do not impair the antibacterial properties of the synthetic phages, indicating that this could be a good strategy to clear space from phage genomes in order to enable the introduction of other genes of interest that can potentiate the future treatment of P. aeruginosa infections.

Automated summary

In an era where bacteriophages are considered as a promising therapeutic approach for dealing with antibiotic resistance, genetic modifications to enhance antibacterial properties present challenges due to limited DNA encapsulation capacity. By knocking out up to 48% of genes encoding hypothetical proteins from the genome of a newly isolated Pseudomonas aeruginosa phage, synthetic phages with smaller genomes were designed and assembled for the first time. Both in vitro and in vivo studies demonstrated that the knock-outs in phage genomes did not compromise antibacterial efficacy, suggesting that this strategy could facilitate the introduction of other genes of interest for future treatment of P. aeruginosa infections.