Mississippi State University
Kiess, Aaron S.
Date of Degree
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Graduate Thesis - Open Access
Master of Science
College of Agriculture and Life Sciences
Department of Poultry Science
Avian pathogenic Escherichia coli and Clostridium perfringens cause economic and welfare concerns to the broiler industry. The recent shift to no antibiotics ever (NAE) production has increased disease incidence. The objectives of this study were to determine the influence of season, age of flock, and sample type on E. coli prevalence and virulence and to identify C. perfringens prevalence and toxinotypes in NAE farms. Results indicated high prevalence of virulent E. coli; prevalence of virulent E. coli decreased from Spring to Summer. Virulent E. coli showed high resistance to antimicrobials. Serogroups O8 and O78 were most prevalent in virulent E. coli. C. perfringens prevalence was very low and all recovered isolates were toxinotype A with variation in netB, cpb2, and tpeL presence. In conclusion, NAE farms should have measures to control E. coli infections, especially in spring season. Further studies are required to confirm the lower prevalence of C. perfringens.
Mississippi Agriculture and Forestry Experiment Station. Strategic Research Initiative (SRI). MIS-322380, United States Department of Agriculture, Agricultural Research Service (USDA-ARS). Specific cooperative agreement. Systems Approach to Understanding and Mitigating Avian E.coli Infections and Antimicrobial Resistance in the Poultry Environment.
Fancher, Courtney, "Prevalence and molecular characteristics of avian pathogenic Escherichia coli and Clostridium perfringens in 'no antibiotics ever' broiler farms" (2021). Theses and Dissertations. 5102.
Available for download on Monday, May 15, 2023