314 THE ALCALIGENES DYSENTERY TYP.HOI I) 



maximum about 44 C. The resistance of Bacillus alcaligenes to 

 physical and chemical reagents is similar to that of the typhoid bacillus. 

 Products of Growth. Bacillus alcaligenes is characterized culturally 

 by its inertness. Neither acid nor gas is produced from any known 

 sugar. A moderate amount of proteolysis similar in degree to that 

 of the typhoid bacillus in sugar-free broth is characteristic of the 

 development of this organism in all the ordinary media. 1 Milk is 

 not coagulated nor peptonized, but a progressive alkalinity develops, 

 associated with the liberation of small amounts of ammonia. 2 No 

 enzymes have been detected, and no toxins have been demonstrated 

 in cultures of the organism. 



FIG. 44. Bacillus alcaligenes; bouillon culture. X 1000. 



Pathogenesis. The comparatively few cases of infection with 

 Bacillus alcaligenes have not been studied in sufficient detail to throw 

 any light upon the character of the lesions produced by the organism. 

 The disease resembles typhoid fever clinically, and it is possible that 

 in the past occasional typhoidal fevers have been incorrectly diagnosed. 

 Animal experimentation has been uniformly negative. 



Immunity. Nothing definite is known of the immunological rela- 

 tions of Bacillus alcaligenes. Specific agglutinins have been demon- 

 strated in a few instances where infection with the organism has been 

 confirmed bacteriologically. 



Bacteriological Diagnosis. The organism may be isolated occasion- 

 ally from the blood; ordinarily, however, the diagnosis is made by 

 the isolation of the bacilli from the feces. Upon the Endo medium the 

 organism grows precisely like the typhoid bacillus. It is readily dif- 



1 Kendall, Day and Walker, Jour. Am. Chem. Assn., 1913, xxxv, 1216. 



2 Ibid., 1914, xxxvi, 1940. 



