Novel Pre-harvest Interventions and Alternatives to Antibiotics to Reduce Foodborne Pathogens

<p>Objective 1. Develop and evaluate potential alternatives to antimicrobials and other intervention products and strategies to control and reduce foodborne pathogens in poultry and swine. Sub-objective 1.a. Select, chemically synthesize and screen antimicrobial peptides (AMP) for ability to kill Campylobacter spp. in vitro. Sub-objective 1.b. Couple the gene for expression of the selected AMP to the gene encoding a well-defined Campylobacter bacteriophage receptor binding protein, Gp047 (short derivative), and express the constructs in yeast. Sub-objective 1.c. Evaluate in vitro and in vivo efficacy of the most active AMP or AMP-receptor binding protein (RBP) products expressed in yeast (purified or as yeast lysate) and, as necessary, develop encapsulation procedures for enhanced stability, site-directed delivery, efficacy and storage of the protein. Sub-objective 1.d. Conduct Campylobacter challenge trials in broiler chickens to determine the ability of oral administration of AMP or AMP-RBP products to reduce Campylobacter colonization and utilize 16S rRNA sequencing to determine the effect of the peptide products on the overall cecal microbiota. Objective 2. Develop, validate and determine the efficacy of a multi-serotype and multi-subunit cross specific vaccine for use in controlling Campylobacter and Salmonella. Sub-objective 2.a. Identify epitopes of the pathogens from peptide microarrays using chicken serum samples from the field. Sub-objective 2.b. Construction and expression of the epitope containing genes in an Escherichia (E.) coli expression system and purification of the recombinant proteins. Sub-objective 2.c. Assay of the immune response in broilers to these recombinant proteins. Sub-objective 2.d. Examination of populations of bacteria in chicken gastrointestinal tract (GIT) after vaccination to determine the effects of vaccines on the microbiota of the GIT.</p>