Vibriosis vaccine development: Immunological characterization of Vibrio alginolyticus

Abstract

The lipopolysaccharide (LPS) profiles of five Vibrio alginolyticus strains (14, 17, 26, 78 and ATCC 17749) were studied by SDS-PAGE. Strains (ST) 14, 17 and 26 were found to possess high molecular weight bands, suggesting that their LPS was highly immunogenic. ST 78 and ATCC possessed only low molecular weight bands, suggesting that their LPS was not highly immunogenic. The LPS and FKC antigens of ST 17, 26 and 78, were injected intraperitoneally in seabass (Lates calcarifer) at 0.2 mg/fish and 0.1 ml/fish at 11.9 X 106 CFU/ml, respectively. Fish were also vaccinated by immersion in formalin-killed cells (11.9 X 106 CFU/ml) for 15 minutes. The mean agglutination titers of fish immunized with ST 17 and 26 were higher compared to strain 78. Fish immunized with antigens from strain 17 showed the highest protection and the protection being significantly different (p<0.05) from that of ST 78. Fish immunized with LPS from the three strains showed significantly (p<0.05) higher protection (survival rate of 80-90%) than that of those injected with FKC. LPS, was thus shown to be a good candidate for a vaccine against vibriosis.