Submitted to: Catfish Culture Research Symposium
Publication Type: Abstract Only
Publication Acceptance Date: February 24, 2006
Publication Date: February 24, 2006
Citation: Shelby, R.A., Shoemaker, C.A., Klesius, P.H. 2006. Protection of channel catfish against columnaris disease by passive immunization. In proceedings of Catfish Culture Research Symposium. Technical Abstract: Columnaris disease caused by Flavobacterium columnare is the second most prevalent disease problem in channel catfish production. At least 50% of operations reported the disease in 2003. It is important to understand the role of antibody in the immune response of catfish to this bacterium. Passive immunization, or injection of fish with anti-columnaris antibody from different sources, is one way to understand the role of antibody in resistance to this disease. We passively immunized channel catfish (NWAC-103) using antibodies developed in goats and in channel catfish by subcutaneous injection of formalin killed sonicated whole cells of F. columnare from Sheih broth culture. Additionally, antiserum was developed in channel catfish by injection with the polysaccharide fraction isolated from F. columnare cells. Antibody levels in goat and fish sera were confirmed by ELISA before the serum was injected. Whole sera were heat-inactivated to denature complement and injected into young (4-5 gram) channel catfish in triplicate treatment tanks. As controls, normal serum from immunologically naive channel catfish, or Sheih broth was injected. This was followed 2 days later by challenge with virulent F. columnare. Significantly higher mortalities of 100% and 60% were observed in the broth and normal sera treatments. Channel catfish receiving immune sera resulted in 27% and 20 % mortality for the polysaccharide and whole cell developed sera, respectively. Antiserum produced in goats provided even greater protection with 7% mortality. We previously demonstrated a cutaneous antibody response following experimental infection with live F. columnare. These data suggest that antibody involved in the protection of channel catfish from columnaris disease.