Identification and Characterization of Salmonella Phages and Absence of Salmonella Strains from Three Different Study Areas of Cattle Livestock

Background: Salmonella represents a significant risk to both public and animal health. Although Salmonella strains have not been isolated from cattle livestock, Salmonella phages have been successfully identified. Materials and Methods: Our study was conducted through (i) investigating the presence of Salmonella strains and Salmonella phages in three study areas, (ii) phenotypic screening by lytic profile (LP); (iii) selecting nine phages for sequencing; and (iv) genomic comparison to evaluate their relative diversity. Results: A total of 307 samples were analyzed, resulting in a total of 162 virus-like particles (VLPs) analyzed. The LP was performed to identify Salmonella strains susceptible to phage infection, including the most frequent serovars: Dublin, Enteritidis, and Javiana. From the VLPs, nine phages were selected for genomic comparison. These phages represent three morphotypes: siphoviruses, myoviruses, and podoviruses, originating from different geographic and productive sites. Conclusions: This study enhances the understanding of the presence and diversity of Salmonella phages in cattle livestock, even in the absence of Salmonella strains.