Location: Aquatic Animal Health Research
Project Number: 6010-10600-002-000-D
Project Type: In-House Appropriated
Start Date: Jan 27, 2025
End Date: Jan 26, 2030
Objective:
1. Identify and characterize existing and emerging catfish and tilapia pests and pathogens including Flavobacterium, Aeromonas, Streptococcus spp. and trematodes.
1.A: Adapt a F. columnare multilocus sequence typing scheme to F. covae.
1.B: Sequence whole genomes of S. agalactiae and identify genetic diversity.
1.C: Sequence and assemble the genome of Bolbophorus damnificus.
2. Characterize immune responses of catfish and tilapia and develop safe and effective vaccines for warmwater finfish pathogens.
2.A: Evaluate the efficacy of killed A. hydrophila vaccines delivered via the oral route and determine the role of specific antibodies in immune protection.
2.B: Evaluate the efficacy of F. covae recombinant protein vaccines delivered orally and determine the correlates of immunity that govern protection.
2.C: Determine the ability of S. agalactiae vaccines formulated with different capsular polysaccharide (CPS) types to provide protective immunity.
2.D: Determine the effect of coinfections on disease severity and immune responses in warmwater fish species.
3. Develop strategies to utilize natural bioactive compounds and bio-based waste products to improve catfish and tilapia health.
3.A: Determine the antibacterial activity of bioactive compounds obtained from lemon pulp and onion skin and evaluate their ability to provide protection against bacterial challenge in channel catfish.
4. Develop strategies to control algal blooms in catfish and shrimp aquaculture.
4.A: Determine if resistance in phytoplankton communities to copper sulfate treatments reduce aquaculture water quality through a negative feedback loop.
4.B: Evaluate the impact that reductions of planktivorous fish have on water quality and fish health and production in catfish aquaculture ponds.
Approach:
Catfish and tilapia are two important industries of US aquaculture production. Farmers continually identify disease as one of the main factors negatively impacting US catfish and tilapia production which jeopardizes the long-term sustainability and profitability of these industries. These economic losses are not only due to animals that die during production, but also due to poor performance of animals during a disease epizootic (e.g., lack of feeding) and costs associated with use of medicated feeds and chemical treatments. These disease outbreaks can be complex in nature, often involving multiple aquatic pathogens in a co-infective manner. Diagnostic laboratory reports and communication with stakeholders have identified Aeromonas hydrophila (vAh), Flavobacterium covae (columnaris disease), Bolbophorus sp., and coinfections as important pathogens impacting the catfish industry. Communication with stakeholders from the tilapia industry have identified Streptococcus agalactiae as the top pathogen of concern. This project will take a multifaceted approach to accomplish four objectives that address the host, pathogen, and environmental interactions that are critical for improving aquatic animal health in aquaculture. The goals of this project are to 1) characterize catfish and tilapia pathogens to aid in vaccine development and control strategies, 2) characterize immune responses of fish and develop effective vaccines, 3) develop strategies to utilize natural bioactive compounds to improve fish health, and 4) develop strategies to control algal blooms in aquaculture. Our approach will use state of the art technologies to characterize pathogen genetic diversity, host responses to vaccination, and environmental interactions that are critical for the development of alternative to antibiotics such as vaccines, natural bioactive compounds, and functional feed additives to boost immune readiness of fish. Such tools are needed to reduce the economic impact associated with disease and therefore increase the profitability and sustainability of these important aquaculture industries. We will also thoroughly evaluate the effectiveness and longevity of algal bloom treatments as well as determine what factors improve or weaken treatment efficacy. Results from this research will reduce disease losses thereby increasing the profitability and production efficiency in the catfish and tilapia industries.
