Enzyme-linked immunosorbent assay for determination of antibodies to Vibrio cholerae toxin-coregulated pili.

An ELISA for determination of antibodies to V. cholerae TCP was developed. Since purified TCP preparations contained detectable amounts of LPS (as shown by ELISA and immunoelectron microscopy with anti-LPS polyclonal serum), a capture ELISA was used. In this test the plate was coated with anti-TCP monoclonal antibody followed by incubation with TCP fimbriae. By this procedure no LPS bound to the solid phase as shown by the loss of reactivity with anti-LPS serum. The capture ELISA allowed sensitive and specific determination of TCP antibodies in sera of rabbits immunized with classical but not El Tor V. cholerae strains. There was good agreement between results in the TCP ELISA and reactivity with the TcpA band in immunoblot analyses when antisera raised against classical and El Tor vibrios were studied.