Serological Studies with Mycoplasma synoviae

Abstract

Mycoplasma synoviae, represented by WVU 1853 strain, was adapted to grow in broth. A rapid-serum-plate (RSP) agglutination antigen was prepared, and its specificity was confirmed by inoculating Mycoplasma synoviae into chickens. Sera from these birds often reacted with the M. gallisepticum RSP antigen, but were negative with the tube agglutination and hemagglutination-inhibition tests. Birds infected with M. gallisepticum did not react to M. synoviae RSP antigen. The capillary tube agglutination and gel diffusion analysis showed no antigenic similarity between M. synoviae and M. galli-septicum. A limited survey of chicken flocks in Massachusetts, using the RSP test, indicated the presence of M. synoviae antibodies. All flocks which were considered positive to the M. synoviae antigen, had histories of infectious synovitis. Sera from birds inoculated with Erysipelothrix rhusiopathiae bacterin and avian mycoplasma serotoype P also produced an RSP reaction with M. gallisepticum antigen. The positive M. gallisepticum-RSP reactions produced by these agents and by M. synoviae were associated with a rheumatoid activity factor in the serum. Treatment of the sera with 2-mer-captoethanol removed the positive RSP reaction. Passive transfer of this rheumatoid factor from the dam to the chick did not occur.