Comparison of different antigenic preparations of Coxiella burnetii used for antibody detection in guinea pigs.

The dynamics of antibody response in guinea pigs infected with Coxiella burnetii was investigated by microagglutination (MA) and complement-fixation (CF) tests with different preparations of C. burnetii antigens. At the onset of antibody response the highest antibody titres were detected by the MA test with natural antigen 2, later on by the MA test with artificial antigen 2. Throughtout the 1-year period of observation, the CF antibody levels were usually lower and, with the exception of the highest infectious doses, the CF antibodies appeared later than agglutinating antibodies. There was no difference in the appearance of agglutinating and CF antibodies directed to antigen 1. Inactivation of the sera caused a marked decrease in antibody titres when tested with artificial antigen 2, whereas the antibody levels remained unchanged when tested with natural antigen 2.