The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to develop technology to reduce pathogenic salmonella carriage in poultry. The challenge addressed is the one of foodborne bacterial gastrointestinal infections. These infections are significant causes of morbidity and mortality worldwide. Of alarming concern is the emergence of bacteria that are resistant to antibiotics. A major source of drug-resistance development is the widespread use of antibiotics in animal production. An estimated 70% of all antibiotics produced in the US are administered to livestock, primarily to promote growth and improve feed efficiency, even in the absence of infection. This sub-therapeutic administration of antibiotics to animals creates a vast reservoir for the selection of drug-resistant bacteria. As a potential solution to this problem, probiotic bacteria will be engineered that express and secrete antimicrobial peptides (AMPs) in the gastrointestinal (GI) tract of animals. In this application, the focus is on chickens, a significant source of animal protein in diets around the globe. Foodborne Salmonella infects millions of people in the US every year, and the major source of Salmonella poisoning are poultry products. The goal is to reduce carriage of Salmonella in chickens to ensure safe food and reduce the need for antibiotics.<br/><br/>This Small Business Innovation Research Phase I project will assess a new, transformative antibiotic technology. Antibiotic, AMP-producing probiotics will be used to reduce pathogens in poultry intestines. Pathogens in poultry intestines are considered the major source of contamination of poultry meat during processing. AMPs are small proteins with remarkable bactericidal properties. Probiotics will be tested as AMP-delivery vehicles. Probiotics are bile-resistant microorganisms that can be delivered safely in food or water. Synthetic biological DNA promoter regions will be employed to precisely control the delivery of AMPs at the site of infection. The impact of controllable AMP delivery will be examined in poultry challenged by Salmonella Enteritidis, a common foodborne pathogen. The impact will be examined for live biotherapeutic bacteria on the microbiota present in the GI tracts of poultry. This project will result in the following advances in discovery/development: 1) Discovery of antimicrobial peptides that selectively target Salmonella spp. 2) Development of peptide expression and secretion cassettes for probiotics; 3) Development of probiotics that competitively inhibit the growth of Salmonella spp.; 4) Development of probiotics that may be supplied safely to farm animals; and 5) Development of probiotics that positively modulate the gut microbiome of poultry.