Isolation, characterization and application of a novel polyvalent bacteriophage SF02 for the control of Salmonella and Escherichia coli O157:H7 in foods

Abstract

Salmonella and E. coli O157:H7 are two important foodborne pathogens that present a significant peril to human health. Recently, bacteriophages have attracted attention as a new type of bacteriostatic agents. In this study, a polyvalent phage named SF02 was isolated and purified, the morphology, biological characteristics, host range, and complete genome sequence of the phage were analyzed. The results indicated that phage SF02 is a long-tailed phage and belongs to the family of Ackermannviridae, and with no toxin and antibiotic resistance genes. The host range showed that SF02 had lytic activity against 33 strains of Salmonella out of 42 strains, and also had lytic activity against E. coli O157:H7. In addition, It also stable at temperature ranging from 30～60 °C and pH values from 3～11. The SF02 with a relatively short latent period of 15 min and a burst size of 94 and 63 PFU/infected cells in Salmonella and E. coli O157:H7, respectively. Furthermore, Viable Salmonella and E. coli O157:H7 were significantly reduced in ready-to-eat chicken claw and pork loin after treatment with SF02 at 4 °C for 10 h. In summary, these results suggest that the SF02 has potential as a candidate for controlling foodborne pathogens in food.