Bactericidal and physico-chemical properties of a lectin derived from spring chinook salmon (Oncorhynchus tshawytscha) Ova

• Main Author: Banowetz, Gary Michael
• Other Authors: Fryer, J. L., Microbiology, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Chinook salmon > Diseases; Pink salmon
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/7p88ck51f

Unfertilized ova from spring chinook salmon (Oncorhynchus tshawytscha) were examined for the presence of classical salmonid inmmunoglobulin. Immunodiffusion techniques in which rabbit anti-salmonid immunoglobulin was reacted against an ova homogenate and rabbit anti-ova homogenate was reacted against immune chinook serum failed to detect classical-type antibodies within these eggs. A lectin with bactericidal properties was isolated from spring chinook salmon ova. This protein agglutinated human type B and rabbit erythrocytes, but not human type A, O or sheep red cells. Hemagglutination was inhibited by D-galactose and L-rhamnose. The protein was purified by affinity chromatography and by gel filtration on Bio-Rad P300. The purified lectin contained a minor (0. 8 %) carbohydrate moiety. A rabbit antiserum was prepared against the protein and used to determine whether ova from coho salmon (O. kisutch), pink salmon (O. gorbuscha), chum salmon (O. keta), kokanee salmon (O. nerka), steelhead trout (Salmo gairdneri), Lahonten cutthroat trout (S. clarki henshawi) or fall chinook salmon (O. tshawytscha) contained a similar protein. All species tested had an immunologically identical protein within their ova. Purified spring chinook salmon ova lectin was bactericidal for two serotypes of Vibrio anguillarum, Pasteurella piscidida, Aeromonas hydrophila and Flexibacter columnaris, but not for Yersinia ruckeri, A. salmonicida, Edwardsiella tarda, Cytophaga psychrophila or the agent of bacterial kidney disease, Corynebacterium sp. In addition to these known bacterial fish pathogens, 19 species of bacteria commonly associated with humans were tested; none of the human-associated agents were inhibited by the lectin. Proteins immunologically identical to the spring chinook salmon ova lectin were purified froim ova of seven other salmonids and found to possess little, if any, activity against the bacterial fish pathogens. Even the protein purified from fall chinook salmon ova had minimal bactericidal activity. Less than 1. 0 μg ...