Abstract

Introduction: The rise of Salmonella Infantis poses a global concern, particularly within the poultry industry. In certain regions, S. Infantis stands out as a prevalent and extensively distributed serovar, exhibiting multidrug resistance. Addressing this issue calls for innovative interventions. Purpose: The objective of this study was to validate the efficacy of a phage cocktail (PC) in mitigating MDR S. Infantis in chicken breast while evaluating its influence on meat quality. Methods: A PC of three phages specific to S. Infantis, underwent validation through testing effectivity on 71 S. Infantis strains isolated from retail poultry meat. The stability of the PC was assessed in vitro at 0ºC in a marinate solution and peracetic acid (PAA) (200 ppm) solution The application model included two approaches with titer of 108PFU/mL: injection and spraying the PC. Both models were tested in 25g of chicken breast inoculated with 104 CFU of SI. Quantification through Most Probable Number (MPN) and the evaluation of quality parameters (pH, color, and aerobic counts) were performed over 4 days at 0ºC. Experiments were conducted in triplicate and the statical analysis by GraphPadv10.2.1. Results: The PC showed efficacy against 98% of tested SI strains. The phage activity remained stable at 0ºC and in the marinate solution, but a significant decrease occurred with 200 ppm PAA within 1 hour. Injection showed a significant phage reduction in comparison with the spray model. For the infection model, spray was used. Salmonella detection was below the limit (<3 MPN per g) on days 0 and 4. Throughout the 4-day period, chicken breast pH remained constant at 6 in both control and phage-treated groups, with no observable color differences. The cocktail-treated group exhibited a significant reduction in total aerobic count compared to the control on day 4. Significance: The developed phage cocktail d