Listeria monocytogenes growth and survival on peaches and nectarines as influenced by stone fruit packing house operations, storage and transportation conditions.

The recent multi-state Listeria monocytogenes outbreak associated with stone fruit consumption highlights the potential for stone fruits to serve as a vehicle in Listeria transmission. Further, the outbreak also demonstrates the pathogen’s ability to persist and survive on stone fruits during handling, storage and transportation. While investigations on the persistence of Listeria have been performed on other produce, there is a general lack of knowledge on the behavior of pathogens associated with stone fruits.  Additionally, each produce type has unique compositional and physical characteristics that require produce-specific management practices. Therefore, to develop stone fruit-specific risk reduction knowledge and preventive controls, this study will investigate the survival and growth of Listeria on peaches and nectarines under packing house environment, storage and transportation conditions. The study will be performed under conditions simulating stone fruit unloading and staging, waxing and fungicide application, storage and transportation from the packing facility.  It is expected that results from this study will provide quantifiable data on the effect of current practices on Listeria survival on stone fruits. Furthermore, identification of food safety risks associated with different steps within the packing house continuum will help develop comprehensive preventive controls for foodborne pathogens including Listeria monocytogenes.