BACILLI OF THE COLON-TYPHOID-DYSENTERY GROUP 709 



organisms themselves may be killed by heating to 60 and the cultures 

 filtered. According to Doerr, 25 the toxins may be obtained in the dry 

 state by precipitation with ammonium sulphate and re-solution of the 

 precipitate in water. 



More recently, Olitsky and Kligler 28 have repeated and extended 

 the thorough study of the Shiga dysentery toxin made by Todd. 27 These 

 writers differentiate definitely between a so-called exotoxin and an endo- 

 toxin. Their exotoxin they obtained by growing the Shiga bacilli for five 

 days in alkalin-egg broth. Their endotoxin was produced by incubating 

 agar growths in salt solution for two days and filtering. The exotoxin 

 in small fractions of a cubic centimeter, after an incubation time 

 of a few hours to four days, produces typical paralysis and severe 

 nerve lesions in rabbits. This poison was killed by 75 C. after one 

 hour, and powerful neutralization was obtained with the serurn of 

 horses immunized with it. Their endotoxin, so-called, produces 

 loss of weight and diarrhea in the animals, but no paralysis. In 

 general, their results agree with those of Krause, Todd, Pfeiffer and 

 Ungermann, 28 and Bessau. 29 They have produced far more potent 

 toxins and more powerful antitoxins than previous workers. 



The action of the dysentery toxin upon animals is extremely char- 

 acteristic and throws much light upon the disease in man. The injec- 

 tion of a large dose intravenously into rabbits causes a rapid fall 

 in temperature, marked respiratory embarrassment, and a violent 

 diarrhea. This is at first watery, later contains large amounts of blood. 

 If the animals live a sufficient length -of time, paralysis may occur, the 

 animal may fall to one side or may drag its posterior extremities. It is 

 a remarkable fact that intravenous inoculation gives rise to intestinal 

 inflammation of a severe nature, unquestionably due to the excretion 

 of the poison by the intestinal mucosa and limited, usually, to the 

 cecum and colon, rarely attacking the small intestine. Flexner, 30 who 

 has experimented extensively upon this question, believes it probable 

 that most of the pathological lesions occurring in the intestinal canal 

 of dysentery patients are referable to this excretion of dysentery toxin, 

 rather than to the direct local action of the bacilli. 



25 Doerr, "Das Dysenterie toxin," Jena, 1907. 



26 Olitsky and Kligler, Jour. Exper. Med., 31, 1920, 19. 

 " Todd^BTit. Med. Jour., 2, 1903, 1456. 



28 Pfeiffer and Ungermann, Cent, f . Bakt., Orig., 50, 1909. 



29 Bessau, Cent. f. Back. 57, 1911, 21. 



30 Flexner, Jour. Exp Med., 8, 1906. 



