The antigenic structure of PPLO (Mycoplasma hominis) and related bacteria.

Abstract

SUMMARY: By gel-diffusion precipitin and antigen-absorption tests, 34 strains of PPLO (Mycoplasma hominis, types 1-4) were examined, and 15 antigenic components recognized. Antigens a, b, f and g were common to types 1, 2 and 4; c was specific to type 1; h was specific to type 2. Type 3 was antigenically unrelated to the remainder. Its two recognizable components were named j and k. Three further antigens in type 1 were recognized as 17, 39 and 40, previously defined in strains of Haemophilus and Coryne-bacterium associated with mycoplasma-like variants (Pease & Laughton, 1965); antigen 40 also occurred in type 2. Two diffusible antigens, α and β, were detected in strains of types 1 and 4; these and also g were found to be shared with the bacterial strains. All genital strains of mycoplasma isolated in this laboratory belonged to type 1, all oral strains to type 4; one rat strain belonged to type 2. Distribution of antigenic components in strains of mycoplasma and in different strains of bacteria, including those believed to be derived from mycoplasma (or vice versa), and also in others, notably Haemophilus influenzae, supports previous claims of relationship between Mycoplasma hominis types 1, 2 and 4, Corynebacterium and Haemophilus. The validity of Mycoplasma as a distinct group of micro-organisms is thus called into question.