Mechanistic determinants of bacteriophage efficacy in food systems: Comparative analysis of two caudoviricetes phages targeting escherichia coli and salmonella enterica

Foodborne pathogens such as Salmonella enterica and Escherichia coli continue to represent a significant global food safety challenge, thereby motivating the development of natural and sustainable antimicrobial interventions. This study investigated mechanistic determinants of bacteriophage efficacy under food-relevant conditions using two newly identified obligately lytic bacteriophages belonging to the class Caudoviricetes —CF01 (targeting E. coli ) and SW01 (targeting S. enterica ). Both phages were characterized for adsorption kinetics, one-step growth, multiplicity of infection (MOI)–yield relationships, thermal stability, and antibiofilm activity, and their performance was evaluated in inoculated chicken, beef, and lettuce at 4°C and 21°C. SW01 exhibited a short latent period (10–20 min), large burst size (∼8–10 × 10 3 PFU per cell), and greater relative thermal resilience at 50°C, achieving >99.9% bacterial reduction and ∼80% biofilm clearance in food matrices. CF01 displayed faster adsorption and a broader host range, but lower productivity (∼2–3 × 10 2 PFU per cell). Replication-associated traits, particularly burst size, yield at optimal MOI, and thermal tolerance, were closely aligned with antibacterial and antibiofilm performance, whereas adsorption rate showed limited predictive value. These findings provide a quantitative framework that links phage replication kinetics within bacterial hosts to antibacterial efficacy in real food systems, thereby providing a mechanistic basis for rational phage selection. The distinct performance profiles of CF01 and SW01 support their potential use in sustainable, “green” biocontrol strategies for mitigating E. coli and Salmonella contamination in food systems.