Theses and Dissertations

Issuing Body

Mississippi State University


Sukumaran, Anuraj

Committee Member

Zhang, Li

Committee Member

Kiess, Aaron S.

Date of Degree


Original embargo terms

Complete embargo for 2 years

Document Type

Graduate Thesis - Open Access


Poultry Science

Degree Name

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.

Available for download on Monday, May 15, 2023