Abstract
A 37 kDa major outer membrane protein (MOMP) was purified from the outer membrane fraction ofEdwardsiella tardaEF-1 strain. The protein had a glycoprotein profile and showed immunogenicity to Japanese eelAnguilla japonica. Immunoblot analysis by using an eel antiserum raised against this MOMP revealed no antigenic cross-reaction with other MOMPs of this bacterium. Eel antisera against 37 kDa MOMP extracted from EF-1 and V1 strains showed cross agglutination to formalin-killed cells and heated cells between the two strains. The results indicate that the heat-resistant antigen, 37 kDa, MOMP is located on the cell surface and has a common antigenic determinant. Immunization with the purified 37 kDa MOMP of EF-1 and V1 strains increased resistance in eel against challenge by intraperitoneal injection with live EF-1 strain. The results show that this 37 kDa MOMP is one of the protective antigens ofE. tarda. As the MOMP was found in two strains of different serotypes, it is probably contributed as a promising vaccine antigen against edwardsiellosis caused byE. tarda.
