Potential to Use Ultraviolet-Treated Bacteriophages to Control Foodborne Pathogens

Abstract

The use of replication-deficient UV-treated bacteriophages, or phages, presents an alternative to viable phages for food biocontrol applications. Nontransducing UV-treated phages, if used correctly, are unlikely to produce viable progeny phages, which might otherwise mediate undesirable horizontal gene transfer events. Phage T4 and Escherichia coli were used as a model system to examine this possibility. UV-treated phages were able to cause a reduction in the optical density of outer membrane-free cell suspensions and they also killed host cells under conditions not permitting their multiplication, that is, 24°C for 2 h and 37°C for 15 min. Host cell reductions were also demonstrated in broth and on meat at 5°C when high concentrations of phages of 2.3 × 10⁹ PFU mL⁻¹ and 1.8 × 10⁸ PFU cm⁻², respectively, were used. At 24°C and 37°C, “lysis from without” was likely to be the mechanism responsible for the reduction in host cell concentrations, but at 5°C this may not have been the case.