Erythrocyte-sensitizing substance from Rickettsia Canadia

Erythrocyte-sensitizing substance (ESS) extracted from Rickettsia canada reacted with homologous sera as well as with sera containing antibodies against Rickettsia prowazeki, but did not react with sera containing antibodies against Rickettsia conori or Coxiella burneti. This finding confirms the antigenic relatedness of R. canada to the typhus rickettsiae group.