Project Number: 1935-41420-012-00
Project Type: Appropriated

Start Date: Jan 19, 2006
End Date: Jan 18, 2011

Objective:
The objectives include: i) elucidate the ecology (persistence, predominance, behavior, and community analysis) of pathogens in various food matrices; specifically focus on foods considered high risk by the stakeholder regulatory agencies (FSIS and FDA), for example ready-to-eat foods, or foods with a short shelf life. ii) develop and validate intervention strategies used either alone or in combination with other processes for pathogen control. iii) elucidate/define (including at the molecular level) the pathogens physiological responses to various intervention strategies and processes. Examine the influence of the inherent food macro and micro-environments.

Approach:
Microbiological studies will be conducted with commercial and laboratory developed foods to determine how varying food matrices, processing environments, indigenous flora, or conditions associated with food distribution alter the persistence, clonality, or succession of food borne pathogens and threat agents. The predominance, persistence, and succession of pathogens along the food chain and in foods such as ready-to-eat (RTE) meats, dairy products and poultry products will be determined using conventional and molecular methods to detect and track the microorganisms. Studies will identify critical control points for the application of interventions. Isolates that predominate and persist will be used for inoculated package studies and/or will be evaluated for virulence potential. Food borne pathogens or food security threat agents will be purposefully inoculated into high risk foods (e.g. milk, RTE meats, and cheese) and pathogen viability will be monitored throughout food manufacture and projected shelf life to quantify the lethality of select food processes. Product processing conditions will be identified and used to optimize pathogen destruction and food quality. New and existing microbiological and genomic/proteomic technologies will be used to delineate the genes, proteins, and integrated physiological response networks expressed by food with food processing and storage. The genes for the identified traits or networks will be mutated and these strains will be compared to wild types to assess the importance of the genes and related physiological traits for pathogen survival and growth within foods.