Grant: Strategic Projects - Group

Bacterial infections caused by food or water contamination affect almost half the world's population each year. In Canada, about 74% of gastrointestinal infections come from food. There are from 5000 to 7000 confirmed cases of foodborne illness in Canada every year, but the estimated total is 2.2 million (Health Canada). The numbers are related for the U.S.: 10,000 to 15,000 confirmed cases, and 6.5 to 33 million estimated. Foodborne illness costs the Canadian economy an estimated $1.3 billion dollars per year. Bacteriocins, non-toxic antimicrobial peptides from non-pathogenic bacteria that grow naturally on food, are prime candidates for enhancing food safety and preventing foodborne illness through control of pathogens. This application requests funding to examine lactic acid bacterial strains that grown naturally on food and produce multiple bacteriocins that work synergistically against a broad range of pathogens. The project focuses on preservation of chilled raw and processed meat products (e.g. sliced luncheon meats) as well as on understanding the mechanism and targets of the bacteriocins at a molecular level. This work will examine interactions of bacteriocins with their protein receptors in the target pathogens, will determine whether a variety of different specific receptors exist, and will analyze the best combinations of bacteriocins and their producers to maximize meat preservation and safety. The project is a collaboration between research groups in food science and in chemical biology. In particular, the project will first examine several strains of Carnobacterium maltaromaticum that produce at least three bacteriocins, some of which are known (piscicolin 126, caraobacteriocin BM1), but some of which are not yet identified. As related type Da bacteriocins (leucocin A, carnobacteriocin B2, pediocin PA1) are believed to bind to membrane proteins on the cell surface involved in bacterial import of mannose, the mannose phosphotransferase system (mpt) will be examined first as a target for these antimicrobial peptides.