SALMONELLA, E. COLI AND LISTERIA ON DAIRY FARMS

Authors: Van Kessel, Jo Ann

Submitted to: USDA-MOST Food Safety/Ag Processing Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2005
Publication Date: 9/22/2005
Citation: Van Kessel, J.S. 2005. Salmonella, E. coli and Listeria on dairy farms [abstract]. USDA-MOST Food Safety/Ag Processing Workshop. p. 12.

Interpretive Summary:

Technical Abstract: Although pasteurization and regulations controlling the processing of any products made with unpasteurized milk have an excellent record of assuring the biological safety of dairy products marketed in the US, there is increasing concern about the presence of zoonotic pathogenic microorganisms in raw milk. For various cultural and economic reasons the consumption of raw milk and desire for products made from raw milk seems to be increasing, and outbreaks of food-borne gastrointestinal disease due to contamination of dairy products have been documented. Our research is focused on the ecology of the zoonotic bacterial pathogens, Salmonella, Listeria monocytogenes, and pathogenic Escherichia coli, on dairy farms in the Northeastern United States. We are characterizing the relationships of the pathogens found in farm animals and the farm environment with those found in bulk tank milk from those farms. Initially, we conducted a national survey to determine the prevalence of these pathogens in bulk tank milk. Subsequently, we are conducting intensive longitudinal sampling on three dairy farms with collection of milk, milk filters, blood, feces, and various environmental samples. Samples are analyzed for the three pathogens by both molecular and culture techniques. Additionally, collaborators analyze the samples for Mycobacterium avium paratuberculosis, Campylobacter, and enterococci. Molecular characterization techniques are being used to compare pathogens found in bulk tank milk with those found on the farm. An increased understanding of the on-farm ecology of zoonotic pathogens will yield new management strategies for the reduction or elimination of contaminated products leaving the farm.