Evaluation of the effectiveness and safety of bacteriophage vB_Sen-Miriam1 against Salmonella enterica in in vitro and in vivo models.

The global rise of antibiotic-resistant Salmonella strains poses a significant public health threat, necessitating the development of alternative antimicrobial strategies. In this study, we present the isolation, characterization, and comprehensive evaluation of the therapeutic potential of a lytic bacteriophage, vB_Sen-Miriam1, targeting Salmonella enterica, using both in vitro and in vivo models. The phage demonstrated a strong lytic activity against multiple Salmonella strains and exhibited therapeutically relevant properties, including a short latent period, high burst size, and stability across a wide range of temperatures and pH values. The phage vB_Sen-Miriam1 possesses a single, circular, double-stranded DNA genome of 43,763 bp with a GC content of 49.9 %. The phage genome analysis confirmed an absence of genes associated with lysogeny, virulence, or antibiotic resistance. vB_Sen-Miriam1 effectively reduced mature biofilm biomass and significantly reduced bacterial counts both extracellularly and intracellularly in the UMNSAH/DF-1 chicken fibroblast infection model. Moreover, in the Galleria mellonella larvae model, the phage treatment increased larval survival while exhibiting no signs of toxicity. These results suggest that vB_Sen-Miriam1 is a promising candidate for further development as a biocontrol agent against Salmonella infections.