428 Diphtheria 



of the toxin molecules become changed into toxons or tox- 

 oids and the poisonous quality is lost though the power of 

 combining with antitoxin remains. 



The toxin is intensely poisonous, and a filtered bouillon 

 containing it may be fatal to a 3OO-gram guinea-pig in doses 

 of only 0.0005 c.c. It is thought not to be an albuminous 

 substance, as it can be elaborated by the bacilli when 

 grown in non -albuminous urine, or, as suggested by Uschin- 

 sky, in non-albuminous solutions whose principal ingredient 

 is asparagin. The toxic value of the cultures is greatest 

 in the second week. 



This soluble toxin so well known in bouillon cultures is 

 probably only one of the poisonous substances produced by 

 the bacillus. An intracellular, insoluble toxic product 

 seems to have been discovered by Rist,* who found it in the 

 bodies of dried bacilli, and observed that it was not neu- 

 tralized by the antitoxin. 



Palmirski and Orlowski f assert that the bacillus pro- 

 duces indol, but only after the third week. Smith, { how- 

 ever, found that when the diphtheria bacillus grew in 

 dextrose-free bouillon no indol was produced. 



The acidity of the culture media depends upon the 

 formation of lactic acid. 



Pathogenesis. Diphtheria in man is characterized by a 

 pseudo-membranous inflammation of the mucous mem- 

 branes, particularly of the fauces, though it may occur upon 

 other parts of the body and is not infrequent in the nose, in 

 the mouth, upon the genital organs, or upon wounds. Wil- 

 liams has reported a case of diphtheria of the vulva, and 

 Nisot and Bumm have reported cases of puerperal diphtheria 

 from which the bacilli were cultivated. It is in nearly 

 all cases a purely local infection, depending upon the 

 presence and development of the bacilli upon the diseased 

 mucous membrane, but is accompanied by a serious intoxi- 

 cation resulting from the absorption from the local lesions 

 of a poisonous metabolic product of the bacilli. The bacilli 



*"Soc. de Biol. Paris," 1903, No. 25. 



f'Centralbl. f. Bakt. u. Parasitenk.," March, 1895. 



J"Jour. of Experimental Medicine," Sept., 1897, vol. n, No. 5, 

 p. 546. 



"Amer. Jour, of Obstet. and Dis. of Women and Children," Aug., 

 1898. 



