Isolation and characterization of virulent bacteriophages and controlling Salmonella Enteritidis biofilms on chicken meat.

Salmonella is a prominent zoonotic pathogen that continues to represent a large threat to food safety and public health worldwide. Concurrently, the inappropriate use of antibiotics has led to the development of antibiotic-resistant strains of Salmonella, highlighting the urgent need for new approaches to manage these bacteria. In this context, virulent bacteriophages are increasingly recognized as a potential and effective biological control method against Salmonella. This study identifies two newly isolated virulent Salmonella phages, phage vB_SalD_ABTNLS3 (S3 for short) and phage 2-3 (2-3 for short). Both phages exhibited effectiveness in preventing biofilm formation and reducing biofilm. S3 and 2-3 could maximize the inhibition of more than 70% and 91% of biofilm formation after 48 h of treatment, and maximize the removal of more than 59% and 96% of mature biofilm after 3 h and 5 h, respectively. Based on these, our study assessed the efficacy of 2-3 in controlling Salmonella enterica serotype Enteritidis (SE) on raw chicken meat at 4°C with varying MOIs, including 1, 100, and 10,000. The maximum reduction observed in SE on chicken meat was 1.15 log CFU/mL following a 12-h treatment with the 2-3, a significant decrease of more than 92% compared to the initial levels present in the experiment (MOI = 10,000). In conclusion, our phages performed well in controlling biofilm and disinfecting refrigerated food at 4°C, suggesting their potential as biological agents to reduce Salmonella contamination in the food industry.