Measurement of immunoglobulin M, immunoglobulin G, and immunoglobulin A antibodies against Yersinia enterocolitica by enzyme-linked immunosorbent assay: comparison of lipopolysaccharide and whole bacterium as antigen.

An enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of human immunoglobulin M (IgM), IgG, and IgA antibodies against Yersinia enterocolitica by using lipopolysaccharides as antigens is described. The results obtained with the lipopolysaccharide ELISA were compared with the results of the whole bacterium ELISA. The correlations observed were good for each immunoglobulin class. Cross-reactions between Y. enterocolitica serotypes O:3 and O:9, Yersinia pseudotuberculosis IA, and Brucella abortus were studied by human and rabbit antisera in the whole bacterium and lipopolysaccharide ELISAs and by rabbit antisera using ELISA inhibition. The greatest cross-reactivity observed was that of the anti-Brucella serum with Y. enterocolitica O:9 in the whole bacterium ELISA. In the lipopolysaccharide ELISA this cross-reaction was not demonstrable with the rabbit antiserum, but it was strong with the human antiserum. However, differential diagnosis was possible with ELISA inhibition. On the basis of our experience, we are now routinely using whole bacterium ELISA for the determination of class-specific Yersinia antibodies, and potential cross-reactions are controlled by the ELISA inhibition.