Studies on the Antigenicity of Bacterial Polysaccharides Part 2: On the Relationship Between Precipitation by B. Proteus X19 Polysaccharide and Weil-Felix Reaction

With the use of polysaccharide of B. Proteus X19 extracted by trichloracetate method, the author has performed precipitation between this polysaccharide and anti-serum of the rabbit immunized with Proteus X19 on one hand, and this polysaccharide against serum of Febris exanthematicus patient and serum of those having anamnesis of typhus exanthematicus and Febris exanthematicus on the other hand; and comparing these results with those with Weil-Felix reaction performed concomitantly, the following results have been finally obtained. 1) In the precipitation with anti-Proteus X19 rabbit serum by antigen-antibody-dilution method, various values have been found to be: antigen titer, 1:50,000; antibody titer, 1:25; and antigen titer of binding zone, 1:10,000; while the agglutination titer has been 1:2,500. 2) Antibody has remained in those patients having anamnesis of typhus exanthematicus or Febris exanthematicus. In the precipitation with their serum antigen titer has been fonnd to be 1:250-1:2,500; while the agglutination by Weil-Felix reaction has been 1:100-1:500. Furthermore, in the precipitation with serum of Febris exanthematicus patient antigen titer has been found to be 1:250-1:1,000; while the agglutination titer is 1:250-1:1,000. 3) The antigen titer of precipitation runs parallel to the agglutination titer of Weil-Felix reaction. 4) This polysaccharide seems to possess a special feature which makes it possible to be kept for a long period of time.