title: 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 degrees C for 2 h and 37 degrees C for 15 min. Host cell reductions were also demonstrated in broth and on meat at 5 degrees C when high concentrations of phages of 2.3 x 10(9) PFU mL(-1) and 1.8 x 10(8) PFU cm(-2), respectively, were used. At 24 degrees C and 37 degrees C, "lysis from without" was likely to be the mechanism responsible for the reduction in host cell concentrations, but at 5 degrees C this may not have been the case.
authors.affiliation: Food Safety Programme, Christchurch Science Centre, Institute of Environmental Science and Research Limited, Ilam, Christchurch, New Zealand. andrew.hudson@esr.cri.nz
authors.forename: John Andrew
authors.initials: JA
authors.lastname: Hudson
authors.forename: Teresa
authors.initials: T
authors.lastname: Bigwood
authors.forename: Aruni
authors.initials: A
authors.lastname: Premaratne
authors.forename: Craig
authors.initials: C
authors.lastname: Billington
authors.forename: Beverley
authors.initials: B
authors.lastname: Horn
authors.forename: Lynn
authors.initials: L
authors.lastname: McIntyre
mesh_terms: D000818:Animals; D001433:Bacteriolysis; D017122:Bacteriophage T4 / Q000502:physiology / Q000528:radiation effects; D001435:Bacteriophages / Q000502:physiology* / Q000528:radiation effects*; D002417:Cattle; D015169:Colony Count, Microbial; D004261:DNA Replication; D004926:Escherichia coli / Q000254:growth & development / Q000821:virology; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000517:prevention & control*; D007700:Kinetics; D008460:Meat / Q000382:microbiology; D008461:Meat Products / Q000382:microbiology; D050296:Microbial Viability; D010572:Pest Control, Biological / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays