BACILLI OF THE COLON-TYPHOID-DYSENTERY GROUP 657 



as to whether these poisons are so-called endotoxins only, or whether 

 they are in part composed of soluble toxins comparable to those of 

 diphtheria and tetanus, following the injection of which antitoxic sub- 

 stances may be formed. 



The evidence so far seems to bear out the original contention of 

 Pfeiffer, 50 who first advanced the opinion that the poisonous substances 

 are products of the bacterial body set free by destruction of the bacteria 

 by the lytic substances of the invaded animal or human being. These 

 poisons, when injected into animals for purposes of immunization, in 

 Pfeiffer's experiments, did not incite the production of neutralizing or 

 antitoxic bodies, but of bactericidal and lytic substances. That these 

 endotoxins constitute by far the greater part of the toxic products of 

 the typhoid bacillus can be easily demonstrated in the laboratory, by 

 the simple experiment of filtering a young typhoid culture (eight or 

 nine days old) and injecting into separate animals the residue of bacilli 

 and the clear filtrate respectively. In such an experiment there will be 

 little question as to the overwhelmingly greater toxicity of the bacillary 

 bodies as compared with that of the culture filtrate. On the other 

 hand, if such cultures, especially in alkaline media, are allowed to 

 stand for several months and the bacilli thus thoroughly extracted by 

 the broth, the toxicity of the filtrate is found to be greatly increased. 



Nevertheless, more recent experiments by Besredka, 51 Macfadyen, 52 

 Kraus and Stenitzer, 53 and others have tended to show that, together 

 with such endotoxic substances, typhoid bacilli may produce a true toxin 

 which is not only obtainable by proper methods from comparatively 

 young typhoid cultures, but which fulfills the necessary requirement 

 of this class of poisons by producing in treated animals a true antitoxic 

 neutralizing body. 



The typhoid endotoxins may be obtained by a variety of methods. 

 Hahn 54 has obtained what he calls " typhoplasmin " by subjecting them 

 to a pressure of about four hundred atmospheres in a Buchner press. 

 The cell juices so obtained are cleared by filtration. Macfadyen has 

 obtained typhoid endotoxins by triturating the bacilli after freezing 



50 Pfeiffer, Deut. med. Woch.. xlviii, 1894; Pfeiffer und Kolle, Zeit. f. Hyg., xxi, 

 1896. 



51 Besredka, Ann. de 1'inst. Pasteur, 1895, 1896. 



52 Macfadyen and Rowland, Cent. f. Bakt., I, xxx, 1901; Macfadyen, Cent. f. 

 Bakt., I, 1906. 



53 Kraus und Stenitzer, Quoted from "Handb. d. Tech.," etc., 1, Fischer, Jena, 

 1907. 



i4 Hahn, Munch, med. Woch , xxiii, 190G. 



