A novel bacteriophage SJW01A capable of infecting multidrug-resistant Salmonella: Isolation, characterization, and application as biocontrol in milk

In this study, a strain of Salmonella -infecting virulent phage, designated as SJW01A, was isolated and purified from a river water used the double-layer agar plate method. SJW01A demonstrated a latent period of 20 min and a burst size of 125 PFU/infected cell when infecting Salmonella . Notably, it exhibited remarkable stability within the pH range of 2–12 and temperature range of 30–60 °C, which was highly advantageous compared to many known bacteriophages. The genome of SJW01A was 47,459 bp in length, with a G + C content of 46.22% and 73 coding sequences (CDS). SJW01A was identified as a new member of the Segzyvirus genus. Virulence factors, antibiotic and lysogeny-related genes were not detected in phage genome sequencing. Importantly, SJW01A significantly inhibited simulated contaminated Salmonella contamination in milk at both 4 °C and 25 °C ( p < 0.05), and no Salmonella was detected in milk in the low concentration treatment group after 1 day at 4 °C. The results suggested that SJW01A is a potential biocontrol agent against Salmonella contamination in food. • A novel phage capable of lysised multidrug-resistant Salmonella was isolated and identified. • SJW01A contains 47459 bp dsDNA encoding 73 CDS. • Phage SJW01A was stable over a wide range of temperatures and pH values. • SJW01A could significantly reduce the growth of Salmonella in milk.