Doctoral Dissertations

Date of Award

8-2003

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Food Science and Technology

Major Professor

Frances Ann Draughon

Abstract

Geographic Information System (GIS), a computer mapping and analysis technology, has emerged as an innovative epidemiological tool in a variety of disciplines. However, the application of GIS to food safety research has received little attention. This study utilized GIS and automated riboprinting technology to examine relationships that existed between animals and their environments, monitoring transmission of pathogens on the farm environment and to nearby surface water environments. A comprehensive epidemiological survey was conducted at The University of Tennessee, Knoxville Experiment Station research dairy farm. More than 40,000 animal and environmental samples were analyzed for Salmonella, Campylobacter jejuni and Escherichia coli 0157:H?. A survey of the Tennessee River, adjacent The University of Tennessee research dairy farm, was also conducted to determine the incidence of these pathogens in the river. Automated riboprinting was used to compare bacterial isolates from various species, locations, and sample types. Salmonella (32%) was the most frequent pathogen isolated on the farm, followed by C. jejuni (21 %) and E. coli 0157:H? (2%). Feed, bedding, water, insects and bird droppings were identified as significant vectors of transmission of pathogens to animals and farm environments. Results of this study indicate that controlling access to animal feed and water sources by insects and wild birds could reduce transmission of pathogens to dairy animals and farm environments. Neither C. jejuni nor E. coli 0157:H? were recovered from the Tennessee River. However, Salmonella was isolated from sampling sites upstream and downstream from the dairy farm. Salmonella was recovered at increased frequency in the Tennessee River at the dairy farm and sites upstream from the farm. Salmonella ser. Senftenberg, Typhimurium, Havana and Newport were the most frequently isolated Serotypes at the dairy farm and from the river. Salmonella ser. Havana, isolated from farm and river water samples, was the only detected serotype showing similar riboprint patterns. Based on pathogens isolated at the farm and not in the river, the variable pattern of Salmonella isolation in the river, and detection of few similar Salmonella serotypes, it was concluded that the dairy farm did not contribute significantly to contamination of the river.

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