Immunoreactivity of the recombinant proteins and the vector tags. (A): Immunoblot analysis of the BPT-Ct, the BPT, the GST-Ct and the GST using 6 human sera. Lane 1: purified BPT-Ct, lane 2: purified BPT, lane 3: purified GST-Ct, lane 4: purified GST. Each column represents the reactivity of one serum to the four antigens. Column 1 and 2: sera from healthy blood donors, column 3: serum from prostitute, column 4, 5 and 6: sera from MIF C. pneumoniae positive patients. (B): ELISA results using the GST and the GST-Ct as antigens obtained with the 356 sera. Each dot represents the GST-Ct reactivity according to that of the GST for the same serum.