Characterization of two virulent Salmonella phages and transient application in egg, meat and lettuce safety

Salmonella, a prominent foodborne pathogen, has posed enduring challenges to the advancement of food safety and global public health. The escalating concern over antibiotic misuse, resulting in the excessive presence of drug residues in animal-derived food products, necessitates urgent exploration of alternative strategies for Salmonella control. Bacteriophages emerge as promising green biocontrol agents against pathogenic bacteria. This study delineates the identification of two novel virulent Salmonella phages, namely phage vB_SalS_ABTNLsp11241 (referred to as sp11241) and phage 8-19 (referred to as 8-19). Both phages exhibited efficient infectivity against Salmonella enterica serotype Enteritidis (SE). Furthermore, this study evaluated the effectiveness of two phages to control SE in three different foods (whole chicken eggs, raw chicken meat, and lettuce) at different MOIs (1, 100, and 10000) at 4°C. It's worth noting that sp11241 and 8-19 achieved complete elimination of SE on eggs after 3 h and 6 h at MOI = 100, and after 2 h and 5 h at MOI = 10000, respectively. After 12 h of treatment with sp11241, a maximum reduction of 3.17 log₁₀ CFU/mL in SE was achieved on raw chicken meat, and a maximum reduction of 3.00 log₁₀ CFU/mL was achieved on lettuce. Phage 8-19 has the same effect on lettuce as sp11241, but is slightly less effective than sp11241 on chicken meat (a maximum 2.69 log₁₀ CFU/mL reduction). In conclusion, sp11241 and 8-19 exhibit considerable potential for controlling Salmonella contamination in food at a low temperature and represent viable candidates as green antibacterial agents for food applications.