Characterization and Genomic Annotation of Salmonella and Escherichia coli-specific Bacteriophages

Abstract

The primary objective of this research was to characterize five lytic bacteriophages specific to Salmonella enterica and Escherichia coli strains by determining their host range. Genetic sequencing of the phages was pursued to identify their genus and genomic attributes.Thirty-eight strains, among them Salmonella and Shiga toxin-producing E. coli (STEC) strains, were used to evaluate the host range of the phages through a “spot-on-the-lawn” plaque assay. The genomes of the bacteriophages were sequenced and annotated using bioinformatics tools, showing the phages to be members of the genus Epseptimavirus. The sequencing and annotation of bacteriophage genomes provided valuable insights into their replication and infection processes. This included the identification of various potential proteins, encompassing functions such as packaging, replication, nucleotide metabolism, host lysis, tRNAs, and structural putative genes for each phage which contributed to a more comprehensive understanding of their genomic features. No virulence genes were detected. More in vitro research will be performed to see how these five phages might be used to reduce the quantity of Salmonella spp. and STEC in food systems. Nevertheless, the outcomes of this study show their potential as tools in food applications for biocontrol of pathogens including pathogenic E. coli O157:H7 strains. This aims to contribute to safer and more reliable food processing practices, ultimately enhancing the safety and quality of the food supply chain for the benefit of consumers worldwide.