ARS | Publication request: Efficacy of a modified live Flavobacterium columnare vaccine in fish

Submitted to: Fish and Shellfish Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2010
Publication Date: November 6, 2010
Repository URL: http://handle.nal.usda.gov/10113/55545
Citation: Shoemaker, C.A., Klesius, P.H., Drennan, J.D., Evans, J.J. 2010. Efficacy of a modified live Flavobacterium columnare vaccine in fish. Fish and Shellfish Immunology. 30:304-308.

Interpretive Summary: Flavobacterium columnare is a common Gram-negative aquatic bacterium that causes columnaris disease in most freshwater fish. This aquatic pathogen is responsible for $30-40 million in losses to the farmed channel catfish industry in the United States each year. We developed and tested a modified live F. columnare vaccine in channel catfish and largemouth bass (an important sportfish). Results demonstrated safety following vaccination. Protection was also demonstrated in the vaccinated fish following challenge with virulent F. columnare. This developed vaccine is a tool that can be used in the health management of catfish and largemouth bass to prevent losses from columnaris disease.

Technical Abstract: Flavobacterium columnare is an aquatic bacterium that is responsible for columnaris disease. This aquatic pathogen has a worldwide distribution and is highly infectious to both warm and cold water fish. A modified live F. columnare vaccine was developed through repeated passage of a virulent strain on increasing concentrations of rifampicin that resulted in attenuation. Here we report vaccination/challenge trials to evaluate efficacy and safety. In separate laboratory trials, immersion vaccination of channel catfish (Ictalurus punctatus) fry between 10 to 48 days post hatch (DPH) with experimental serials or licensed vaccine resulted in relative percent survival (RPS) between 57-94% following challenge. Similarly, a vaccination/challenge trial using largemouth bass (Micropterus salmoides) fry at 10 DPH was performed using various doses of licensed vaccine under laboratory conditions. Results demonstrated safety of the vaccine and significant protection following challenge with RPS values between 74-94%, depending on vaccine dose. Together, these trials demonstrate the vaccine administered to early life-stage channel catfish and largemouth bass is safe and reduces mortality following challenge with F. columnare.