Summary of Awards to Date

Biocontrol of human pathogens in tomato and sprouted seed production using bacterial isolates derived from natural environments.

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May. 1, 2007 - Apr. 1, 2009

Award Number


Funding Agency

Center for Produce Safety

Amount Awarded



Keith Warriner, Ph.D.
University of Guelph


M Kostrzynska, (AAFC), K. Dunfield (Land Resource Science, UoG)


In recent years there have been numerous outbreaks of foodborne illness linked to fresh produce such as tomatoes, lettuce, spinach and sprouted seeds. Because produce is eaten raw there are no steps in the chain that can effectively eliminate pathogens, such as Salmonella, should a contamination event occur. It is now well established that washing can reduce levels of pathogens on produce but cannot relied upon to completely eliminate them. Therefore, the most effective control method would be to prevent contamination of the fruit or vegetable at the production stage. Yet, because of the multiple sources of pathogens in the field (soil, water, manure, insects, wild animals) finding a practical method to control human pathogens is problematic. Spraying strong sanitizers onto growing plants is impractical due to damage cause to the plant, in addition to disrupting the microecology of the environment. The following project aims to develop a method based on using a combination of friendly microbes to attack pathogens on plants. The general approach will be to isolate antagonistic bacteria from fresh produce and combine these with bacteriophage (viruses that infect bacteria) to control pathogens such as Salmonella, E. coli O157:H7 and Listeria monocytogenes. By using antagonistic bacteria with bacteriophage we anticipate that the pathogen killing effect will be enhanced. Although the approach can be used for a diverse range of fresh produce the current project will focus on sprouted mung bean seeds and tomatoes.