Salmonella and Tomato Infection Interactions to Be Investigated

Salmonella bacteria cause 1.4 million cases of food poisoning in the United States each year. (1) The principal sources of infection are infected meat products and plants that have come into contact with contaminated water.

BTI scientist Gregory Martin, PhD, is the co-principal investigator of research that seeks to determine at the molecular level the mechanisms by which Salmonella is able to survive on produce plants and thus present a risk to human health.

He and principal investigator Craig Altier, PhD, Department of Population Medicine and Diagnostic Sciences College of Veterinary Medicine, Cornell University, aim to identify the genetic networks required by Salmonella to proliferate on and within tomatoes, a known vehicle for transmission of the bacteria to humans, and the means by which the plant may respond to suppress Salmonella infection. This work is important, as vegetables and produce have become major sources of human salmonellosis in this country and around the world. Additionally, nearly nothing is known about the bacterial constituents required for growth in produce plants.

The two scientists will test whether the expression of specific Salmonella genes is required for survival and replication of the pathogen in tomatoes. These genes will be differentially regulated, so that they can be identified through their specific induction upon infection of the plant. They also will examine whether tomato detects Salmonella pathogen-associated molecular patterns (PAMPs), and if this limits infection by the bacterium.

Their work is being funded by a $499,425 award from the National Institute of Food and Agriculture, Food-borne Pathogen-Plant Interactions program.

(1) Mead, P. S., L. Slutsker, V. Dietz, L. F. McCaig, J. S. Bresee, C. Shapiro, P. M. Griffin, and R. V. Tauxe. 1999. Food-related illness and death in the United States. Emerg. Infect. Dis. 5:607-625.

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