# A Lytic Mosigvirus Phage (GADS24) from a Poultry-Farm Environment: Genome-Resolved Characterization and In Vitro Biocontrol-Relevant Phenotyping Against Escherichia coli

## TL;DR

A new lytic phage, GADS24, was isolated from poultry waste in Saudi Arabia and shown to kill some drug-resistant E. coli strains in the lab.

## Contribution

GADS24 is a genome-resolved, strictly lytic Mosigvirus with biocontrol potential against E. coli.

## Key findings

- GADS24 lysed 5 out of 10 clinical E. coli isolates in vitro.
- Genome analysis confirmed GADS24 belongs to the Mosigvirus genus with no lysogeny-related genes.
- The phage has a distinct lineage and is available in GenBank for further study.

## Abstract

Multidrug-resistant (MDR) Escherichia coli (E. coli) at the poultry–human interface motivates evaluating strictly lytic bacteriophages as targeted biocontrol candidates. A lytic E. coli phage (GADS24) was isolated from poultry waste in Saudi Arabia. Plaque formation and host range were assessed against 10 clinical E. coli isolates. Virion morphology was examined by transmission electron microscopy (TEM). Whole-genome sequencing (Illumina) and annotation (Prokka/RAST) were followed by comparative genomics (BLASTn 2.15.0, ANI JSpeciesWS: 2014–2025 Ribocon GmbH—Version: 5.0.3, dDDH GGDC: GGDC 3.0 and phylogenetic/proteomic analyses for taxonomic placement. GADS24 formed clear plaques and lysed 5 of 10 clinical E. coli isolates tested. TEM revealed an icosahedral capsid (~72.6 nm) and a contractile tail (~131.7 nm), consistent with Tevenvirinae/Mosigvirus morphology. The dsDNA genome is 168,896 bp (GC 43.8%) with 268 predicted ORFs and two tRNA genes (tRNA-Arg and tRNA-Met); no lysogeny-related genes were detected. The closest relative was Escherichia phage JN02 (98.44% ANI; 57.8% dDDH), supporting assignment to Mosigvirus while indicating a genome-resolved distinct lineage. The genome is available in GenBank (OQ703618). GADS24 represents a genome-resolved, strictly lytic Mosigvirus with in vitro biocontrol-relevant phenotyping against E. coli, supporting follow-up development for poultry-associated infection control and deeper phage–host interaction studies.