Immune response of rainbow trout (Oncorhynchus mykiss, Walbaum) to Aeromonas hydrophila

Rainbow trout (Oncorhynchus mykiss Walbaum), immunised by injection, immersion and orally with killed and live cells of Aeromonas hydrophila, produced antibodies in the serum, bile, skin and gut mucus, and skin and muscle extracts. The antibodies were of a low affinity macroglobulin class, sensitive to 2-mercaptoethanol, and of a structure comprising heavy and light chains. These antibodies reacted maximally with formalised cells and lipopolysaccharide (LPS), and to a lesser extent with exopolysaccharide (EPS), flagella, S-layer protein and a haemolytic component of the extracellular products (ECP) of A. hydrophila. © 1994 Academic Press. All rights reserved.