Scientific Opinion on the evaluation of the safety and efficacy of Listex™ P100 for the removal of Listeria monocytogenes surface contamination of raw fish.

Studies evaluating the safety and efficacy of Listex™ P100 to reduce Listeria monocytogenes contamination on raw fish were assessed. The material should not present human toxicological problems because the bacteriophage P100, used as active principle, is not regarded as harmful to consumers nor to organisms other than Listeria spp., and because the fabrication parameters do not include anything obvious that might compromise safety. Data of studies considered indicate that Listex™ P100 is listericidal on inoculated catfish and salmon samples, but do not allow definitive conclusions on efficacy in reducing L. monocytogenes counts on raw fish nor on its impact on L. monocytogenes contamination levels in finished product. It was not possible to estimate the potential listeriosis risk reduction by treating raw fish with Listex™ P100. The data were not adequate to allow firm conclusions on persistence or activity of P100 in stored fish. The proposed use of Listex™ P100 is unlikely to result in emergence of reduced susceptibility to biocides and/or resistance to key therapeutic antimicrobials: however, this conclusion may need verification. No information was provided on survival of P100 in processing wastewater or the environment, or on the potential accumulation of naturally P100 resistant L. monocytogenes variants. Pilot and industrial scale studies should consider parameters affecting decontaminating efficacy, and should verify that application on raw fish has an impact on reduction of L. monocytogenes contamination on the final product. The persistence or activity of P100 as well as potential changes in L. monocytogenes counts should be evaluated during fish storage. Tests to investigate potential development of resistance or reduced susceptibility to biocides and key therapeutic antimicrobials, following use of Listex™ P100, are recommended. The continuous effectiveness of Listex™ P100 against L. monocytogenes and the potential for selection and dominance of strains naturally-resistant to P100 should be monitored.