Title: Effectiveness of bacteriophage to control the outgrowth of Listeria monocytogenes on the surface of frankfurters Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 10, 2008
Publication Date: August 4, 2008
Citation: Call, J.E., Porto Fett, A.C., Luchansky, J.B. 2008. Effectiveness of bacteriophage to control the outgrowth of Listeria monocytogenes on the surface of frankfurters. Meeting Abstract. P2-57. Page 96. Technical Abstract: Introduction: There have been numerous studies published on the effectiveness of surface-applied food grade chemical antimicrobials to control Listeria monocytogenes on RTE meat products; however, there is little to no information on the effectiveness of using bacteriophage to control this pathogen in these types of food products. Purpose: To determine if a commercial, Listeriae-specific bacteriophage preparation is effective at controlling L. monocytogenes on frankfurters during storage at 4 degree and 10 degree C. Methods: One pound packages of frankfurters were surface inoculated with approximately 3.0 log10 CFU/package of a multi-strain mixture of L. monocytogenes and then surface treated with 4 mL of either a 9.0 or 7.0 log10 suspension of bacteriophage. Packages were vacuum-sealed and then placed at 4 degree or 10 degree C for up to 21 days. Results: Regardless of storage temperature, relative to control packages, the addition of 9.0 log10 of bacteriophage resulted in an initial reduction of about 0.8 log10 of L. monocytogenes, whereas there was no appreciable reduction in pathogen levels with the addition of 7 log10. After 21 days at 4 degree C, pathogen levels increased by about 0.4 log10 CFU/package in control packages, but were about 1.1 and 0.7 log10 CFU/package lower in packages treated with 9.0 and 7.0 log10 of the bacteriophage, respectively. In contrast, at 10 degree C, pathogen levels increased by at least 5.3 log10 CFU/package in both control packages and packages treated with 9.0 and 7.0 log10 of the bacteriophage preparation after 21 days of storage. Significance: A Listeriae-specific phage preparation can reduce the levels of L. monocytogenes on frankfurters by about 1.0 log10 CFU/package. Further studies are warranted to optimize and validate this bacteriophage preparation as a post-processing intervention to control L. monocytogenes in RTE meat and poultry products.