Application of a novel phage W5 for biological control 1 of Salmonella Typhimurium in different food matrices

Background: Salmonella, as one of the four major foodborne pathogens, poses a serious challenge to global public health. The aim of this paper is to apply phage eradication for biocontrol of salmonellosis in different food matrices. Results: This study isolated a novel lytic phage, designated as W5, isolated from livestock and poultry slaughterhouse effluent. W5 displayed effective lytic activity against prevalent Salmonella serotypes, including Salmonella Typhimurium, Salmonella Choleraesuis, and Salmonella Typhi. Morphological observations indicate that phage W5 belongs to the family Myoviridae and the order Caudoviridae , the whole genome sequencing and phylogenetic analysis also confirmed W5 as a novel species within the Cornellvirus genus of the Guernseyvirinae subfamily . The biological characterization revealed that phage W5 had an optimal infection complex of 1, with a brief incubation period of 22 min followed by a logarithmic phase extending from 22 min to 70 min to peak at a maximum of 3.67 × 10 ¹¹ PFU/mL and achieving a plateau period after 70 min. Moreover, W5 exhibits robust thermal and acid–base stability, optimally active at 50 °C and stable across a pH range of 3 to 13. Neither SM buffer nor glycerol impacted the activity of W5, with 98% of the phage adsorbing to the host bacteria within 13 min of post-mixing. Further tests demonstrated that W5 can inhibit Salmonella in milk, pork, and eggs, effectively prevent biofilm formation, and remove biofilm. These results suggest that phage W5 is abundantly available as a potential antimicrobial agent for Salmonella control in the food industry, owing to its safety and effectiveness. Conclusions: Biological characterization, genome-wide analysis, and application of phage W5 showed that this phage is a promising candidate for use in phage mixtures or other phage-based preparations.