Theses and Dissertations

Issuing Body

Mississippi State University


Wise, David J.

Committee Member

Aarattuthodiyil, Suja

Committee Member

Griffin, Matthew J.

Committee Member

Rosser, Thomas G.

Date of Degree


Document Type

Graduate Thesis - Open Access

Degree Name

Master of Science


College of Forest Resources


Department of Wildlife, Fisheries and Aquaculture


Incidence and prevalence of Edwardsiella piscicida has increased in Mississippi farm-raised catfish in recent years. Edwardsiella piscicida affects mostly market-sized catfish during the final stages of the production cycle resulting in significant economic losses. The objectives of this study were to determine the genetic variability of E. piscicida, assess virulence in channel and hybrid catfish, and evaluate the capacity of a live-attenuated E. ictaluri vaccine to protect channel and hybrid catfish against heterologous E. piscicida isolates. This work identified five discrete E. piscicida lineages, along with group specific associations of several virulence related genes. In general, E. piscicida was shown more virulent in hybrids than channel catfish, in line with previous work. Further, a live-attenuated E. ictaluri vaccine was shown to confer cross-protective immunity in channel and hybrid catfish against E. piscicida.



US Department of Agriculture (USDA) Agricultural Research Service (Grant/Award Number: 58‐6402‐2729) USDA Catfish Health Research Initiative (Grant/Award Number: 6402‐31320‐002‐02)


Edwardsiella piscicida||Channel catfish||Hybrid catfish||Vaccine||Edwardsiella ictaluri