title: Bacteriophage significantly reduces Listeria monocytogenes on raw salmon fillet tissue.
abstract: We have demonstrated the antilisterial activity of generally recognized as safe (GRAS) bacteriophage LISTEX P100 (phage P100) on the surface of raw salmon fillet tissue against Listeria monocytogenes serotypes 1/2a and 4b. In a broth model system, phage P100 completely inhibited L. monocytogenes growth at 4 degrees Celsius for 12 days, at 10 degrees Celsius for 8 days, and at 30 degrees Celsius for 4 days, at all three phage concentrations of 10(4), 10(6), and 10(8) PFU/ml. On raw salmon fillet tissue, a higher phage concentration of 10(8) PFU/g was required to yield 1.8-, 2.5-, and 3.5-log CFU/g reductions of L. monocytogenes from its initial loads of 2, 3, and 4.5 log CFU/g at 4 or 22 degrees Celsius. Over the 10 days of storage at 4 degrees Celsius, L. monocytogenes growth was inhibited by phage P100 on the raw salmon fillet tissue to as low as 0.3 log CFU/g versus normal growth of 2.6 log CFU/g in the absence of phage. Phage P100 remained stable on the raw salmon fillet tissue over a 10-day storage period, with only a marginal loss of 0.6 log PFU/g from an initial phage treatment of 8 log PFU/g. These findings illustrate that the GRAS bacteriophage LISTEX P100 is listericidal on raw salmon fillets and is useful in quantitatively reducing L. monocytogenes.
authors.affiliation: Department of Food Science, Nutrition and Health Promotion, P.O. Box 9805, Mississippi State University, Mississippi State, Mississippi 39762, USA.
authors.forename: Kamlesh A
authors.initials: KA
authors.lastname: Soni
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Nannapaneni
mesh_terms: D000818:Animals; D001433:Bacteriolysis; D001435:Bacteriophages / Q000502:physiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005511:Food Handling / Q000379:methods; D005519:Food Preservation / Q000379:methods; D006801:Humans; D008089:Listeria monocytogenes / Q000254:growth & development*; D012474:Salmon / Q000382:microbiology*; D017747:Seafood / Q000382:microbiology / Q000592:standards; D013696:Temperature; D013997:Time Factors