Isolation and characterization of a novel Salmonella bacteriophage JNwz02 capable of lysing Escherichia coli O157:H7 and its antibacterial application in foods

Abstract

The topic of bacteriophage as an alternative to antibiotics to control pathogenic bacteria has attracted attention. Here, a novel virulent Salmonella bacteriophage JNwz02 capable of cross-infecting E. coli O157:H7 was isolated and characterized. The complete genome of JNwz02 was composed of 114390 bp double-stranded DNA molecules encoding 164 open reading frames (ORFs) with a G + C content of 40.22%. JNwz02 belongs to the Siphoviridae family and has high homology with T5-type phages. The eclipse period and latency of JNwz02 infection with Salmonella were 10 min and 10–15 min, respectively. The burst size and adsorption rate constant K were 200 plaque-forming unit (PFU)/colony-forming unit (CFU) and 6.71 × 10−9 ml/min, respectively. JNwz02 was relatively stable in the range of temperature (30°C-50 °C) and pH (2–11). The viable Salmonella and E. coli O157:H7 were significantly reduced in ready-to-eat duck neck meat and milk after treatment with JNwz02 at 4 °C for 2 d. The results suggested that JNwz02 has potential for application against Salmonella and E. coli in food.