Theses and Dissertations
Advisor
Tekedar, Hasan C.
Committee Member
Lawrence, Mark L.
Committee Member
Hanson, Larry A.
Date of Degree
12-12-2025
Original embargo terms
Embargo 2 years
Document Type
Graduate Thesis - Open Access
Major
Veterinary & Biomedical Sciences (Infectious Diseases)
Degree Name
Master of Science (M.S.)
College
College of Veterinary Medicine
Department
Department of Comparative Biomedical Sciences
Abstract
Bacterial diseases significantly impact U.S. catfish aquaculture. Edwardsiella tarda has historically been isolated from cultured fish species, and remains a zoonotic pathogen detected in disease cases across diverse hosts. This study investigated its potential dissemination pathways and adaptive capacity. Hi-C metagenome deconvolution of cormorant fecal samples showed that E. tarda can interact with gut microorganisms and mobile genetic elements, acquire resistance and virulence genes, and potentially be shed into ponds. Adaptive laboratory evolution under florfenicol exposure revealed the selection of mutations mainly in efflux- and stress-related genes, and resistance accompanied by fitness costs. Together, these findings identify E. tarda as a potential reservoir and vector of antimicrobial resistance in aquaculture, emphasizing its relevance to One Health by linking environmental, animal, and human health through resistance dissemination.
Sponsorship (Optional)
Global Center for Aquatic Health & Food Security; New York Institute of Technology Vancouver
Recommended Citation
O'Donald, Sydney, "Investigating the dissemination of zoonotic bacterium Edwardsiella tarda to aquaculture ponds and its adaptive response to antibiotic pressure" (2025). Theses and Dissertations. 6840.
https://scholarsjunction.msstate.edu/td/6840
