520 PATHOGENIC MICROORGANISMS 



teristic, and almost pathognomonic, is a severe congestion of both 

 suprarenal bodies. The gastric ulcerations recently described by Rose- 

 nau and Anderson ' may occur, but are by no means regularly found 

 (two out of fifty in our series^). 



Diphtheria Toxin.^ — j'Vnimals and man infected with B. diphtherise 

 show evidences of severe systemic disturbances and even organic de- 

 generations, while the microorganism itself can be found in the local 

 lesion only. This fact led even the earliest observers to suspect that, 

 in part at least, the harmful results of such an infection were attrib- 

 utable to a soluble and diffusible poison elaborated by the bacillus. The 

 actual existence of such a poison or toxin was definitely proved by 

 Roux and Yersin '' in 1889. They demonstrated that broth cultures in 

 which B. diphtherise had been gro\yn for varying periods would remain 

 toxic for guinea-pigs after the organisms themselves had been re- 

 moved from the culture fluid by filtration through a Chamberland filter. 



Methods of Production of Diphtheria Toxin. — While toxin can ■ 

 be produced with almost all of the virulent diphtheria bacilli, there 

 is great variation in the speed and degree of production, dependent 

 upon the strain of organisms employed and upon the ingredients and 

 reaction of the medium upon which they are grown. Most labora- 

 tories possess one or several strains of bacilli which are empirically 

 known to be especially potent in this respect. One of the most ex- 

 tensively used, not only in this country, but in Europe as well, is 

 the strain known as "Culture Americana," or "Park- Williams Bacillus 

 No. 8," an organism isolated by Dr. Anna WUliams of the New York 

 Department of Health in 1894. Throughout more than ten years of cul- 

 tivation this bacillus has retained its great power of toxin production. 



Because of the severity of cases of diphtheria in which the diph- 

 theria bacUli were associated with streptococci, many observers were 

 led to believe that the presence of streptococci tended to increase the 

 toxin-producing power of B. diphtherise. Experiments by HUbert,^ 

 Theobald Smith," and others seem to have given support to this view. 



The medium most frequently employed for the production of toxin is 

 a beef-infusion broth. There are minor differences of opinion as to the 



1 Bosenau and Anderson, Journ. Inf. Dis., iv, 1907. 



2 Zinsser, Joum. Med. Res., xvii, 1907. 



3 Loeffler, Cent. f. Bakt., 1887. 

 « Roux and Yersin, loe. cit. 



6 Hilbert, Zeit. f. Hyg., xxix, 1898. 

 'Smith, Medical Rec, May, 1896. 



