Pathogenesis 481 



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 

 are found only in the membranous exudation, and are 

 most plentiful in its older portions. 



The entrance of the diphtheria bacillus into the internal 

 organs can scarcely be regarded as a frequent occurrence, 

 though metastatic occurrence of the organism with and 

 without associated staphylococci and streptococci, and 

 with and without purulent inflammations have from time 

 to time been reported. Such a case of septic invasion by 

 the diphtheria bacillus, with a synopsis of the literature to 

 date, is given by Ucke. f 



The disease pursues a course of variable length, in favor- 

 able cases the patient recovering gradually, the pseudo- 

 membrane first disappearing, leaving an inflamed mucous 

 membrane behind it, upon which virulent diphtheria bacilli 

 persist, always for weeks and sometimes for months. Smith J 

 describes the bacteriologic condition of the throat in diph- 

 theria as follows: "The microscope informs us that during 

 the earliest local manifestations the usual scant miscel- 

 laneous bacterial flora of the mucosa is quite suddenly 

 replaced by a rich vegetation of the easily distinguishable 

 diphtheria bacillus. Frequently no other bacteria are found 



* " Arner. Jour, of Obstet. and Dis. of Women and Children," Aug., 

 1898. 



t "Centralbl. f. Bakt. u. Parasitenk.," original, XLVI, Heft 4, March 

 10, 1908, p. 292. 



J "Boston Med. and Surg. Jour.," 1898, i, p. 157. 



