Abstract
Comparison on the efficacy of ribosomal and other antigens prepared from Pasteurella piscicida was performed. Yellowtail, Seriola quinqueradiata, was immunized twice by intraperitoneal injection using these antigens to determine the efficacy against artificial challenge by virulent P. piscicida. The antigen preparations used were ribosomal antigen P and S (RBP and RBS), outer membrane fraction (OMF), lipopolysaccharide (LPS), precipitated antigens (PCA), extracellular products (ECP) and formalin killed cells (FKC) as control. After three weeks from the last immunization, RBP gave the highest phagocytic activity although lowest in specific antibody against P. piscicida LPS and serum opsonization in various immunized groups. The RBP preparation was the most effective antigen against as compared to the other preparations.
