Date of Award
Doctor of Philosophy
James S. Dickson
Bacterial antimicrobial resistance represents an important current and future problem in infectious disease public health. When reviewing longitudinal studies (studies involving repeated observations of a location over a period of time), very little information was found regarding the proliferation and dissemination of foodborne bacteria in a new dairy farm environment. Iowa State University (ISU; Ames IA) was awarded 887 acres of land by a donor family. An academic teaching farm was later constructed, the Dairy/Animal Science Education Facility (or the ISU Dairy Farm). Prior to building the ISU Dairy Farm, the land was only used for recreational activities-no production livestock had ever been introduced. It was decided to study the bacteria microbiota Enterobacteriaceae (particularly Salmonella), Enterococcus and Campylobacter. Microbiological sampling was conducted using a variety of techniques-from phenotypic methods (e.g. detecting bacteria by using specialized media) to genotypic methods (e.g. Pulsed Field Gel Electrophoresis). Sampling took place prior to dairy cattle placement (20 October 2007 and 13 November 2007) and after placement (27 January 2008, 29 February 2008, 12 March 2008, 23 April 2008 and 28 May 2008). A literature review discussing the introduction of dairy cattle to the United States, antibiotics used in animal production, antibiotic resistance, and the "prudent" (or responsible) use of antibiotics is discussed in chapter 1. Data from the ISU Dairy Farm Studies are included in chapter 2 (the establishment and proliferation of antibiotic-resistant Campylobacter), chapter 3 (the establishment and proliferation of Enterococcus) and chapter 4 (the establishment of Enterobacteriaceae and Salmonella london). Chapter 5 addresses general conclusions of this work and recommendations for future research.
Ginger M. Shipp
Shipp, Ginger M., "A determination of antibiotic resistance before and after the introduction of production livestock" (2009). Graduate Theses and Dissertations. 11040.