Isolation, characterization and antibacterial potential of bacteriophages SGP009, SGP004, and SGP007 targeting Salmonella enterica serovar Gallinarum.

Salmonella Gallinarum causative agent of chicken typhoid, causes severe loss in poultry with multidrug-resistant (MDR) strains reducing antibiotic effectiveness. Bacteriophage therapy represents a promising alternative strategy for combating multidrug-resistant infections. This study aimed on isolating and characterizing bacteriophages against S. Gallinarum (S2) and evaluating their antimicrobial potential. The Bacteriophages were isolated from Ayub Medical Complex Hospital, Abbottabad, DHQ Hospital, Abbottabad and Butt Pull Water Canal in Mansehra. Their host specificity, temperature and pH stability, and antimicrobial activity were assessed. The isolated Bacteriophages SGP009, SGP004, and SGP007 formed clear lytic plaques, showed resistance to pH 2.0 for one hour, and optimal stability at pH 6–9 and 3–6, with temperature stability at 4 °C, 50 °C, and 37 °C, respectively. These bacteriophages demonstrated strong antibacterial activity against S. Gallinarum for up to 28 h without inducing resistant mutants. The isolated Bacteriophages SGP009, SGP004, and SGP007 specifically infected and lysed S. Gallinarum isolates without impacting other bacterial genera exhibiting strong, specific, and stable antibacterial activity against multidrug-resistant Salmonella Gallinarum highlighting their potential as effective targeted biocontrol agents.