Fate of Listeria on various food contact and noncontact surfaces when treated with bacteriophage

• Published in: Journal of food safety Vol. 40; no. 3
• Main Authors: Reinhard, Robert G., Kalinowski, Robin M., Bodnaruk, Peter W., Eifert, Joseph D., Boyer, Renee R., Duncan, Susan E., Bailey, R. Hartford
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-06-2020; Blackwell Publishers Inc
• Subjects: Belts; Epoxy resins; Flooring; Food; Food processing; Food safety; Industrial plants; Listeria; Listeria innocua; Listeria monocytogenes; Manufacturing industry; Phages; Polyurethane; Polyurethane resins; Reduction; Stainless steel; Stainless steels; Temperature effects
• ISSN: 0149-6085; 1745-4565
• DOI: 10.1111/jfs.12775

Study objective was to determine efficacy of a bacteriophage suspension against Listeria spp. when applied to three common types of materials used in food manufacturing facilities. Materials included two food contact materials (stainless steel and polyurethane thermoplastic belting) and one noncontact material (epoxy flooring). Coupons of each material were inoculated with a cocktail containing L. monocytogenes and L. innocua (4 to 5‐log10 CFU/cm2). Two phage concentrations and a control, 0, 2 × 107 and 1 × 108 PFU/cm2 were evaluated. Treated samples were held at 4 or 20°C for 1 and 3 hr to determine the effect of temperature and treatment time. Reductions in Listeria populations ranged from 1.27 to 3.33 log10 CFU/cm2 on stainless steel, from 1.17 to 2.76 log10 CFU/cm2 on polyurethane thermoplastic belting, and from 1.19 to 1.76 log10 CFU/cm2 on epoxy resin flooring. Higher phage concentration (1 × 108 PFU/cm2), longer treatment time (3 hr), and processing area temperature of 20°C showed a greater (p ≤ .05) reduction of Listeria on the stainless‐steel and polyurethane thermoplastic belting coupons. Overall, Listeria reduction by phage treatment occurred on all three materials tested, under all conditions.