The complete genome of lytic Salmonella phage vB_SenM-PA13076 and therapeutic potency in the treatment of lethal Salmonella Enteritidis infections in mice.

S. Enteritidis continues to be the most common pathogen of farm animals and a major public health burden worldwide. Using bacteriophages is a potential alternative to antibiotics against S. Enteritidis infection. In this study, the genome analysis of the lytic phage vB_SenM-PA13076 (PA13076) infecting S. Enteritidis revealed a linear, double-stranded DNA genome, which comprised of 52,474 bp and contained 69 ORFs. It belongs to the order Caudovirales; family Myoviridae, genus unclassified. The genes coded for DNA packaging, phage structural proteins, lysis components, DNA recombination, regulation, modification, and replication. No bacterial virulence or drug-resistance genes were detected. The phage PA13076 protected mice from a lethal dose of S. Enteritidis 13076Amp (5 × 108 CFU) by reducing the concentration of bacterial cells in blood, intestine, liver, spleen, and kidney. The phage PA13076 achieved at least 2.5 log reductions of S. Enteritidis cells in infected mice within 24 h (P < 0.05) when compared to the organs of control mice. The data also indicated that phage PA13076 could rapidly enter the blood and four organs of infected mice, remaining therein at concentrations of>104 PFU/g for at least 72 h. These results show that phage PA13076 has definite potential as an antibacterial therapeutic agent for attenuating S. Enteritidis infections.