AUTHOR=Juliet Ramya , Loganathan Archana , Neeravi Ayyanraj , Bakthavatchalam Yamuna Devi , Veeraraghavan Balaji , Manohar Prasanth , Nachimuthu Ramesh TITLE=Characterization of Salmonella phage of the genus Kayfunavirus isolated from sewage infecting clinical strains of Salmonella enterica JOURNAL=Frontiers in Microbiology VOLUME=15 YEAR=2024 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1391777 DOI=10.3389/fmicb.2024.1391777 ISSN=1664-302X ABSTRACT=

The emergence of multi-drug resistance in Salmonella, causing food-borne infections, is a significant issue. With over 2,600 serovars in in Salmonella sp., it is crucial to identify specific solutions for each serovar. Phage therapy serves as an alternate treatment option. In this study, vB_SalP_792 phage was obtained from sewage, forming plaques in eight out of 13 tested clinical S. enterica isolates. Transmission electron microscopy (TEM) examination revealed a T7-like morphotype. The phage was characterized by its stability, life cycle, antibiofilm, and lytic ability in food sources. The phage remains stable throughout a range of temperatures (−20 to 70°C), pH levels (3–11), and in chloroform and ether. It also exhibited lytic activity within a range of MOIs from 0.0001 to 100. The life cycle revealed that 95% of the phages attached to their host within 3 min, followed by a 5-min latent period, resulting in a 50 PFU/cell burst size. The vB_SalP_792 phage genome has a dsDNA with a length of 37,281 bp and a GC content of 51%. There are 42 coding sequences (CDS), with 24 having putative functions and no resistance or virulence-related genes. The vB_SalP_792 phage significantly reduced the bacterial load in the established biofilms and also in egg whites. Thus, vB_SalP_792 phage can serve as an effective biocontrol agent for preventing Salmonella infections in food, and its potent lytic activity against the clinical isolates of S. enterica, sets out vB_SalP_792 phage as a successful candidate for future in vivo studies and therapeutical application against drug-resistant Salmonella infections.