Location: Warmwater Aquaculture Research Unit
Project Number: 6066-31320-006-000-D
Project Type: In-House Appropriated
Start Date: Dec 14, 2019
End Date: Dec 13, 2024
Objective:
1. Identify emergent pathogens in catfish aquaculture and develop disease diagnostic methodologies for use in field surveillance studies.
1.1. Identify emergent pathogens in catfish aquaculture and develop disease diagnostic methodologies for field surveillance studies.
1.2. Characterize and evaluate pathogenesis of emergent diseases and fulfillment of Koch’s postulates or River’s postulate for newly recognized or emergent pathogens.
1.3. Develop rapid diagnostic tests and ELISA procedures to determine total and antigen specific antibody for epidemiological studies.
1.4. Develop primary catfish cell lines for identification and confirmation of fish viruses.
2. Optimize treatments and management strategies to minimize infectious diseases in catfish aquaculture.
2.1. Optimize Edwardsiella (E.) ictaluri vaccine delivery, evaluate cross protective potential of E. ictaluri vaccine against E. piscicida.
2.2. Role of other myxozoans (non-H. ictaluri) and intraspecific variability of oligochaete hosts in occurrence of proliferative gill disease (PGD) in channel and hybrid catfish.
2.3. Role of iron fortified diets and occurrence of bacterial infections in channel and hybrid catfish.
2.4. Evaluation of the pathophysiological effects of Bolbophorus damnificus (trematode) in hybrid and channel catfish.
3. Determine the epidemiology of infectious diseases in catfish aquaculture and conduct economic evaluations of disease management strategies.
3.1. Significance of genetic E. piscicida variants recovered from commercially cultured hybrid and channel catfish.
3.2. Epidemiology of A. hydrophila infections in catfish aquaculture; predictive modeling to determine risk factors.
3.3. Spatio-temporal survey of channel catfish virus (CCV) isolates and evaluation of trends in the occurrence and virulence of different genetic strains of CCV in channel and hybrid catfish.
3.4. Evaluate disease transmission of emergent Vibrio spp. infections in hatchery fry.
3.5. Economic evaluation of a live, attenuated E. ictaluri vaccine in commercial fingerling and foodfish production.
Approach:
In the United States, pond production of catfish ranks as the leading aquaculture species in terms of farm gate value. Health management strategies, technologies, and bio-security plans that are environmentally safe are necessary to help mitigate disease-related losses. There is presently a lack of validated technologies for early and rapid detection of pathogens, disease prevention, and treatment of diseases in catfish aquaculture, which has hindered the growth and profitability of the industry. Validated diagnostic tools for use in production systems to detect the disease agents in a rapid fashion are needed. In addition to the need for diagnostics, developing effective control strategies to manage disease is a priority, given only a few drugs are available for the treatment of sick fish. Further research will develop molecular based diagnostic tools used in to monitor potential emergent pathogens, optimize vaccination strategies for control of bacterial infections, determine the epidemiology of priority infectious diseases and assess costs and benefits of disease management strategies in hybrid and channel catfish aquaculture.
We will identify emergent pathogens in catfish aquaculture and develop disease diagnostic methodologies for use in field surveillance studies. Specifically, we will characterize and evaluate pathogenesis of emergent diseases and fulfillment of Koch’s postulates or River’s postulate for newly recognized or emergent pathogens, develop rapid diagnostic tests and ELISA procedures to determine total and antigen specific antibody for epidemiological studies, and develop primary catfish cell lines for identification and confirmation of fish viruses. To improve disease management strategies in catfish aquaculture we will optimize Edwardsiella (E.) ictaluri vaccine delivery and evaluate cross protective potential of E. ictaluri vaccine against E. piscicida, determine the role of other myxozoans (non-H. ictaluri) and intraspecific variability of oligochaete hosts in occurrence of proliferative gill disease (PGD) in channel and hybrid catfish, determine the role of iron fortified diets and occurrence of bacterial infections in channel and hybrid catfish, and evaluate the pathophysiological effects of Bolbophorus damnificus (trematode) in hybrid and channel catfish.
In order to determine the epidemiology of infectious diseases in catfish aquaculture and conduct economic evaluations of disease management strategies we will determine the significance of genetic E. piscicida variants recovered from commercially cultured hybrid and channel catfish, determine the epidemiology of atypical Aeromonas hydrophila (aAh) infections in catfish aquaculture, perform a spatio-temporal survey of channel catfish virus (CCV) isolates and evaluate trends in the occurrence and virulence of different genetic strains of CCV in channel and hybrid catfish, evaluate disease transmission of emergent Vibrio spp. infections in hatchery fry, and evaluate economic impact of a live, attenuated E. ictaluri vaccine in commercial fingerling and foodfish production.
