Inhibition of Leptospiricidal reaction by the type-specific main antigen of Leptospira.

The serovar-specificity of the leptospiricidal activity test mediated by antiserum and complement was demonstrated by the fact that the leptospiricidal activity of the antiserum against the serovar-specific main (TM) antigen of copenhageni shibaura and the antiserum against the whole cells of the same strain were inhibited by the homologous but not the heterologous TM antigens. The inoculation of TM antigen produced in a rabbit the antibodies which react in the leptospiricidal activity test. These results may also show that the substance which participates in the leptospiricidal activity test may be the TM antigen.