Immunoblotting analysis of antibody response in swine experimentally inoculated with Mycoplasma hyopneumoniae.

Serological cross-reactivity among swine mycoplasmas, and porcine antibody response to Mycoplasma hyopneumoniae antigens during experimental infection were investigated by enzyme-linked immunosorbent assay (ELISA) and the immunoblotting technique. Mycoplasmas solubilized with Tween 20 were used as antigen. Cross-reactivity between M. hyopneumoniae and M. flocculare was indicated by ELISA and it was demonstrated by immunoblotting, which revealed that the predominant cross-reactive antigens were components of M. hyopneumoniae with molecular weights of 74,000 (74 K) and 53 K. Further, it was indicated that 96 K, 70 K, 46 K and 38 K antigenic components of M. hyopneumoniae and 67 K, 56 K and 23 K antigens of M. flocculare were specific for the respective species. Antibodies to 96 K, 76 K, 70 K, 53 K, 46 K and 38 K antigens were detected in serum from pigs experimentally infected with M. hyopneumoniae. Of these antibodies, those against the 46 K antigen reacted early and were most consistently detected during experimental infection. Therefore, the antibodies against the 46 K antigen of M. hyopneumoniae proved to be excellent markers of mycoplasmal pneumonia of swine.