Isolation and Whole Genome Sequencing of a novel Salmonella lytic bacteriophage

Abstract

Abstract Salmonella is one of the leading causes of foodborne diseases in the world. In this study, Salmonella killing bacteriophage was isolated using the double-layer agar overlay technique and characterization of the phage genome was done. The morphology of phage was studied using Transmission Electron Microscopy. Whole-genome sequencing of phage DNA was performed in the Miseq platform. The genomic DNA library was prepared using the NexteraXT library prep kit method using the NexteraXT index kit. Paired-end sequencing of 2×251 cycles read length; the run was performed using the Miseq V3 kit. Phage formed clear plaques on S. enteritidis in the double agar overlay technique. The electron microscopy revealed that the phage belonged to Myoviridae family. The assembly produced a draft genome of length 161329 bp with a GC content of 44.425% and coverage of 104x. Rapid annotation subsystems technology yielded 333 coding sequences of which 285 proteins were hypothetical and 48 were assigned functions that included DNA ligase, capsid protein, endolysin, and other proteins. A pairwise comparative analysis showed closest genome as Salmonella Phage SSE-121. The study on the phylogenetic tree obtained showed a very close relationship with Salmonella Phage SSE-121 genome with a distance score of 0.1 disclosing it to be a new member of the SSE121 virus.