# Isolation and Genomic Characterization of Two Lytic Cutibacterium acnes Phages Defines Two Novel Pahexavirus Species

## TL;DR

Scientists isolated two new bacteriophages that can kill acne-causing bacteria and could be used as an alternative to antibiotics.

## Contribution

The study introduces two novel lytic phages from acne lesions, expanding the Pahexavirus genus and offering potential phage therapy candidates.

## Key findings

- Two lytic Cutibacterium acnes phages (NS-ph1 and NS-ph2) were isolated and shown to have a broad lytic spectrum against multiple C. acnes strains.
- Genomic analysis revealed linear dsDNA genomes with no genes for lysogeny, toxins, or antibiotic resistance.
- Both phages retained infectivity for three months at room temperature and belong to the Pahexavirus genus.

## Abstract

Bacteriophages are promising antibacterial agents for managing acne vulgaris caused by Cutibacterium acnes, particularly given increasing antibiotic resistance. Here, we isolated and characterized two lytic Cutibacterium phages, NS-ph1 and NS-ph2, from acne lesions. Both bacteriophages exhibited a broad lytic spectrum, with a high activity against 27 C. acnes strains. Adsorption assays indicated rapid attachment and one-step growth experiments revealed latent periods of 4 h (NS-ph1) and 2 h (NS-ph2) and burst sizes of 70 and 59 PFU per infected cell, respectively. After long-term storage at room temperature, both phages retained infectivity for 3 months. Genome sequencing revealed linear dsDNA genomes of 29,490 bp (NS-ph1) and 29,189 bp (NS-ph2) with 51 and 46 predicted ORFs, respectively, and no tRNAs. No genes associated with lysogeny, toxins, or antibiotic resistance were detected. Comparative genomics placed both phages within the genus Pahexavirus. Together, these data expand the diversity of Pahexavirus and provide two well-characterized lytic candidates for further evaluation in anti-acne phage therapy.