Immune response of the prawn, Macrobrachium rosenbergii, to bacterial infection

Abstract

Serum agglutinins of Macrobrachium rosenbergii found in normal serum were reactive toward eight bacterial species and type A human red blood cells. Absorption studies indicated the ability of the agglutinins to distinguish between different bacterial species as well as between certain bacteria and red blood cells. Agglutinin titers were approximately the same for the bacteria, whereas those for red blood cells were significantly higher. A virulent strain of Vibrio anguillarum was used in infectivity experiments. An LD 50 value was determined between 5 × 10 6 and 10 7 cells/animal, and an attempt was made to immunize the animals using formalin-killed cells. The animals did not respond to the vaccination, as there was neither an increase in the level of circulating agglutinins nor the LD 50 level 6 days after injection. Structural and functional traits of serum agglutinins are markedly different from vertebrate antibodies.