Antibody response in salmonids against the 70 kDa serine protease of Aeromonas salmonicida studied by a monoclonal antibody-based ELISA.

An antigen-capture enzyme-linked immunosorbent assay (cELISA) based on monoclonal antibodies (mAb) was set up and evaluated for selective detection of salmonid antibody responses to the antigen P1, which is a weakly immunogenic exoprotease of typical Aeromonas salmonicida. This new assay permits a specific determination of anti-protease-antibodies, without antigen purification. Serum antibodies induced by the strongly immunogenic lipopolysaccharide could reliably be discriminated from anti-P1-antibodies.

Development of an ELISA-system for the assessment of furunculosis vaccines.

As an alternative method for challenge experiments in fish a sandwich-ELISA has been established for the detection of potentially protective antibody populations. Assay specificity depends on monoclonal antibodies (mabs) directed against different antigens of Aeromonas salmonicida, the causative agent of furunculosis. Comparable levels of salmon antibodies against LPS and the A-layer protein were recorded by ELISA and antigen binding assay.

A-protein from achromogenic atypical Aeromonas salmonicida: molecular cloning, expression, purification, and characterization.

Achromogenic atypical Aeromonas salmonicida is the causative agent of goldfish ulcer disease. Virulence of this bacterium is associated with the production of a paracrystalline outer membrane A-layer protein. The species-specific structural gene for the monomeric form of A-protein was cloned into a pET-3d plasmid in order to express and produce a recombinant form of the protein in Escherichia coli BL21(DE3).

Generation and preliminary characterization of monoclonal antibodies directed to glycerophospholipid:cholesterol acyltransferase (GCAT) native epitopes of Aeromonas salmonicida.

Four monoclonal antibodies (MAbs) directed to native glycerophospholipid:cholesterol acyltransferase (GCAT) epitopes of Aeromonas salmonicida were isolated using an esterase capture assay. The molecular mass of this MAb-defined antigen was estimated to be 26 kDa in SDS-PAGE. Three different epitope specificities of these MAbs were demonstrated.

Protein-water interaction energies as predictor for antigenic determinants.

Goodford's GRIN/GRID method is used for the prediction of antigenic determinants of lysozyme by calculation of protein-water interaction energies. The comparison of the regions of high interaction energy with experimentally determined contact surfaces in antigen-antibody complexes and epitopes obtained by cross-reactivity measurements shows a noteworthy agreement. The model is proposed to enlarge the basis of theoretical models for epitope prediction.