Journol of General Microbiology (1 980), 116, 187- 193. Printed in Great Britain An Antigenic Analysis for Membranes of Mycoplasma horninis by Cross-absorption

Antigenic components at the outer surface membranes of seven serotypes of MycopZasma hominis were analysed by the mycoplasmacidal reaction and the agglutination during growth reaction. Antibody absorbing capacities of the mycoplasma cells were compared with the absorbing capacities of membranes. It was shown that serologically active mem-brane antigens were mainly heat-labile proteins. No major antigens common to all seven serotypes were detected and each strain had its own specific antigens at the cell surface. Results of analysis indicate that there is a complex antigenic structure exposed in M. hominis and that 7 to 14 cross-reacting antigens may be present at the outer surface in the different serotypes examined. Additional cross-reacting antigens, presumably inner mem-brane in origin and not exposed at the cell surface, were also demonstrable