322 THE ALCALIGENES DYSENTERY TYPHOID 



Shiga bacillus has an elective affinity for the intestinal mucosa of 

 the large intestine, and it is the toxin secreted by the dysentery bacilli 

 during their multiplication in the intestinal mucous membrane which 

 induces the anatomical and nervous lesions characteristic of the 

 disease. 



Animals. Typical bacillarv dysentery has not been produced in 

 laboratory animals by feeding the organisms. The intravenous inocu- 

 lation or intraperitoneal injection of living or killed broth cultures of 

 Shiga or Flexner bacilli, however, are usually fatal, particularly to 

 rabbits. Vaillard and Dopter, 1 and Flexner 2 have shown that small 

 amounts of forty-eight-hour broth cultures of Shiga bacilli introduced 

 intravenously into young rabbits frequently lead to diarrhea, which 

 at first is mucous in character; later it becomes mucosanguineous. 

 After two or three days symptoms of paraplegia develop. At autopsy 

 the large intestine is swollen and frequently edematous. The mesen- 

 tery is hyperemic with enlarged glands. The intestinal contents are 

 mucosanguineous in character and the intestinal wall is considerably 

 thickened. If the animal survives for several days, more advanced 

 lesions are sometimes seen, particularly beginning ulceration and 

 necrosis. Flexner states that the intestinal lesions of bacillary 

 dysentery in man and in animals are probably due, in part at least, 

 to the direct action of the dysentery toxin. 



Iinmunity and Immunization. Shiga 3 and others have succeeded in 

 immunizing laboratory animals, particularly rabbits, guinea-pigs, and 

 horses, with dysentery bacilli, beginning by injecting killed cultures 

 of these organisms, first with very small amounts which are slowly 

 and cautiously increased, finally with living bacilli. It is difficult to 

 immunize animals because of the toxicity of the organism. The sera 

 of these animals contain specific agglutinins, lysins, precipitins, and 

 opsonins, frequently of high potency. According to Todd, and Kraus 

 and Doerr, 4 specific antitoxins are .also demonstrable in the sera of 

 these animals, particularly in anima'ls immunized to the Shiga bacillus. 

 The agglutinins which are specific for the type of organism used in 

 immunization are, according to Dopter, 5 as a rule of greater potency 

 when killed cultures exclusively are used for immunizing. In thor- 

 oughly immunized animals the agglutinins may be active even in 

 dilutions of 1 to 5000. 



1 Ann. Inst. Past., 1903, p. 472. 



2 Jour. Exp. Med., 1906, vol. viii. 



3 Ztschr. f. Hyg., 1902, xli, 355. 



4 Loc. cit, 5 Loc, cit., p. 84. 



