Start Date: Jun 20, 2006
End Date: Jun 19, 2011
We hypothesize that the response to common stressors of commercial turkey production, including Escherichia coli respiratory disease (airsacculitis), moving and transport, and temperature extremes, can increase pre-harvest contamination of turkeys with pathogens of food safety importance, and that basic understanding of how turkey immunity is affected by stress will lead to the development and application of practical strategies to improve product safety. Because stress has been shown to both increase disease resistance at low levels and decrease disease resistance at high or sustained levels, its effects on food safety have been difficult to quantify. We have developed transport stress and cold stress models which result in repeatable levels of stress-induced infection of turkeys with E. coli. We will use these models to study the colonization of turkeys with other bacteria of food safety importance. Cell culture studies of the interaction between bacterial pathogens and primary turkey synovial cells, macrophages, and heterophils, from normal and stressed animals will provide basic data and systems for testing the efficacy of therapeutic and prophylactic products to modulate the stress response, improve disease resistance, and decrease carcass contamination with pathogens. Novel non-antibiotic interventions will include antimicrobial peptides and acute phase proteins that will be developed using exploratory analysis of physiological reactions in our stress models as described in the previous section. These products will be incorporated into stress models; however variations in both dosage and timing relative to stressor will be emphasized in multiple experiments to maximize production gains while minimizing pathogen contamination.