Isolation and Characterization of Stress-Tolerant Bacteriophages for Effective Biocontrol of Foodborne Pathogen

Foodborne microbial contamination remains a significant challenge for the food industry, impacting public health and causing economic losses. Bacteriophages have emerged as promising biocontrol agents due to their targeted antimicrobial activity, safety, and, importantly, minimal impact on food sensory attributes. However, their stability under food processing conditions remains a bottleneck for practical application. Here, we isolated three stress-tolerant bacteriophages targeting Pseudomonas aeruginosa, an emerging foodborne pathogen, using a sequential stress exposure protocol. These phages remained infective at up to 50 °C, pH 4–11, and 20% NaCl. The phages were able to reduce the growth of P. aeruginosa by 5 log cycles in an artificially contaminated cheese used as a model food matrix. Whole-genome sequencing of one of the phages was performed to confirm its identity, determine genomic determinants of stress tolerance, and screen for antibiotic-resistance genes, virulence factors, and lysogenization genes, ensuring safety as biocontrol agents. This study demonstrates the potential of stress-tolerant bacteriophages to enhance food safety when used in conjunction with conventional food processing techniques.