Serological Relationships among Human Mycoplasmas as Shown by Complement-fixation and Gel Diffusion.

Taylor-Robinson, David (National Institutes of Health, Bethesda, Md.), Norman L. Somerson, Horace C. Turner, and Robert M. Chanock. Serological relationships among human mycoplasmas as shown by complement-fixation and gel diffusion. J. Bacteriol. 85:1261-1273. 1963.-Antigenic relationships among human mycoplasmas were studied by complement-fixation and agar gel diffusion techniques. Four recognized human species Mycoplasma hominis type 1, M. hominis type 2, M. salivarium, and M. fermentans were antigenically distinct in these tests. In addition, M. pneumoniae (Eaton agent, the etiological agent of cold agglutinin-positive atypical pneumonia) was different from these four species. Although these species were distinct, evidence of shared antigenic components was obtained in complement-fixation and agar gel diffusion tests. Since rabbits were immunized with mycoplasmas grown in rabbit muscle infusion broth supplemented with rabbit serum or, in the case of M. pneumoniae, with infected chick embryo lung suspension, the possibility that the heterologous reactions resulted from antibody to growth medium components could be excluded. Four recent mycoplasma isolates from the oropharynx were analyzed, and three were shown to be closely related to M. hominis type 1, and the fourth was closely related to M. salivarium. Although the recent isolates could not be distinguished from the related "prototype" human species by complement-fixation, differences could be detected by the agar gel diffusion technique.