Immunogenic evaluation of the conjugated subunit vaccine against Edwardsiella tarda

PAN Hongwei; SHI Cunbin; ZHAO Yi; LIU Po; WU Shuqin

Abstract：Edwardsiella tarda is an important pathogen in the aquicuhure now, and developing an effective vaecine to prevent this pathogen become necessary. In this study, eels were respectively immunized with the OMP-LPS conjugates, OMP, LPS, and FKC in the experimental group, and immunized with physiological salt solution in the control group in the same procedure. Then lysozyme activity test and micro-agglutination test were perfonned. There was no significant difference of lysozyme activity (P > 0.05) among experimental groups,but any of them was higher than that of the control group (P<0.05); the tiler of E. tarda E29L antibody of OMPC-LPS conjugates was high-er and it lasted longer as compared with that of LPS, OMP, and FKC; when challenging with E. tarda E29L, the prevention rate of OMP-LPS conjugates was 84%, which was higher than that of OMP (80%), LPS (44%) and FKC (60%). Adding ISA763 adjuvant to OMP-LPS conjugates, OMP, LPS and FKC could increase the lysozyme activity (P<0.05), especially OMP-LPS conjugates + ISA763,OMP+ISA763, LPS+ISA763 (P<0.01). Moreover, the prevention rates of all the groups with adjuvant were higher that that of group with-out adjuvant. All the results mean that adjuvant ISA763 can elevate the efficacy of subunit vaccine through promoting adaptive and innate immunity of the fish.