Detection of Specific Antibodies against Renibacterium salmoninarum by ELISA with p57 Protein as a Capture Antigen

Abstract

We evaluated p57 of Renibacterium salmoninarum (R.s.) as a capture antigen for specific antibody-detection ELISA against R.s.. Using formalin-killed R.s. (FK-R.s.) as ELISA antigens, ELISA values (OD_{492 nm}) of the negative control sera showed high values ranging from 0.12 to 1.59. These values were relatively lower than those of sera from the fish immunized with FK-R.s. (0.16-2.6), but seemed to be still high as negative control sera. Contrarily, when p57 was used as a capture antigen, ELISA values of the negative control sera were all 0.1 or less, while those of the sera from immunized fish ranged from 0.02 to 1.28. It was thus demonstrated that high background of ELISA was enabled to be reduced by p57 as ELISA antigens.