Studies on the Spherical Body of an Oral Spirochete

The spherical bodies (SB) of a human oral treponeme strain G7201 were studied by both light and electron microscopy. Cultural effects of temperature, serum, and osmotic pressure on the SB formation were also examined. In order to know the difference in antigenicity between the capsule and the SB-membrane, anti-rabbit sera to normal treponemal cells and spherical bodies were prepared and serological studies were performed. The following results were obtained. 1) The SB appeared within the spirochetal masses with were formed in the presence of a high concentration of sucrose, and were classified into three types (N, B, and C) on the ground of number of organisms on the surface of SB-membrane…