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Bacteriophage Therapy to Control E. coli O157:H7 in Cattle


Pre-harvest control of microbial food-borne and environmental hazards is an essential component of an effective food production system. Our earlier studies showed that bacteriophage (phage) therapy is potentially an effective intervention to control E. coli O157:H7 in cattle, which frequently carry this important human pathogen. The purpose of this project is to study the safety and efficacy of this therapy. We will study the safety of the phages in cattle and animals that share the same environments as cattle (e.g. rodents and birds) and that may be potentially exposed to the phages, and the efficacy of the therapy in cattle, firstly in controlled experimental infection studies in calves, and secondly in naturally infected cattle. This project will be conducted by researchers at the Laboratory for Foodborne Zoonoses of the Public Health Agency of Canada, Lethbridge Research Centre of Agriculture and Agri-Food Canada, and Nymox, a Canadian company, all of whom have considerable experience and interest in phage therapy. The outcomes of this project will provide information required for field trials and eventual transfer of this technology to field use.

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Expected Impact of Project Outcomes on Food Safety in Ontario:
Recognising the impact of E. coli O157:H7 on marketability of cattle products domestically and internationally, cattle producers and processors in Ontario and elsewhere have embraced the need for on-farm control of this organism. Effective interventions at the farm level will not only enhance the microbial safety of cattle food products, but will reduce risks of contamination of water supplies, fresh produce, animals and the environment. Although several on-farm interventions have been investigated, most have met with little or only moderate success. However, we have shown "proof of concept" that treatment of cattle with E. coli O157 phages can potentially eliminate E. coli O157:H7 from cattle. This project addresses several remaining objectives of a larger project designed to further develop and transfer this technology to field use. If successful, this technology will benefit the Food Safety System in Ontario and the agri-food sector in general, through safer beef products, reduced contamination of the environment, water and other foods with E. coli O157:H7, reduced risk of human exposure to E. coli O157:H7, and enhanced market competitiveness in beef products domestically and internationally. <P> For more information, please visit the <a href="; target="_blank">Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA) Food Safety Research Program</a>.

Johnson, Roger
Public Health Agency of Canada (PHAC)
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