# Genomic, Evolutionary and Phenotypic Insights into Pseudomonas Phage Adele, a Novel Pakpunavirus with Potential for Phage Therapy

## TL;DR

This paper introduces a new phage, Adele, that can effectively target Pseudomonas aeruginosa and may be useful for phage therapy.

## Contribution

The discovery and detailed characterization of a novel lytic phage, Adele, within the Pakpunavirus genus, including its genomic and therapeutic potential.

## Key findings

- Phage Adele has a short latent period and high burst size, efficiently lysing Pseudomonas aeruginosa strains.
- Adele provides protection in a Galleria mellonella infection model, indicating therapeutic potential.
- Phage Adele's genome reveals evolutionary relationships and horizontal gene transfer events.

## Abstract

Bacteriophages are powerful drivers of microbial evolution and are increasingly explored as alternatives to antibiotics against multidrug-resistant pathogens such as Pseudomonas aeruginosa. Here, we describe the isolation, phenotypic characterization and genomic, structural and evolutionary analysis of Pseudomonas phage Adele, a lytic myovirus representing a novel species within the genus Pakpunavirus (family Vandenendeviridae). Phage Adele exhibits a short latent period of 20 min, a burst size of 59 ± 11 virions per infected cell and a high virulence index, efficiently lysing non-O11 Pseudomonas aeruginosa strains and reducing biofilm biomass. In vivo, Adele confers marked protection in a Galleria mellonella infection model. Phylogenetic reconstruction, synteny analysis and structural modeling demonstrate the relatedness of Vandenendeviridae to phages of the Andersonviridae and Vequintavirinae clades, pointing to a stable, ancestral virion architecture that has undergone lineage-specific elaborations, including the duplication and divergence of tail tube proteins. The tail assembly chaperone gene employs a conserved −1 programmed ribosomal frameshift. Phage Adele encodes an elaborate set of metabolic reprogramming and anti-defense systems, reflecting extensive horizontal gene transfer. The combination of a conserved structural architecture and mosaic genome establishes Adele as an exemplary system for studying modular evolution in phages, alongside its demonstrated therapeutic efficacy.