BACILLUS ALCALIGENES 351 
A moderate amount of proteolysis similar in degree to that of the 
typhoid bacillus in sugar-free broth is characteristic of the develop- 
ment of this organism in all the ordinary media. ^ ^Milk is not coagu- 
lated nor peptonized, but a progressive alkalinity develops, associated 
with the liberation of small amounts of anmionia.'- No enzymes have 
been detected, and no toxins have been demonstrated in cultures of the 
organism. 
Pathogenesis.— The comparatively few known cases of infection with 
B. alcaligenes have not been studied in sufficient detail to throw any 
light upon the character of the lesions produced by the organism. The 
disease induced usually resembles typhoid fever clinically, and it is 
possible that in the past occasionally typhoidal fe^■ers have been incor- 
rectly diagnosed. Animal experimentation has been iniiformly 
negative. 
Immunity. — Nothing definite is known of the immunological rela- 
tions of B. alcaligenes. Specific agglutinins (g-^) have been demon- 
FiH. 48. — Bacillus alcaligenes; bouillon culture. X 1000. 
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. It may be found in the 
urine in a small percentage of cases. ^ Upon the Endo medium the 
organism grows precisely like the typhoid bacillus. It is readily 
differentiated from the typhoid bacillus by cultural reactions, B. 
alcaligenes forming neither acid nor gas in glucose, lactose, saccharose 
or mannitol. It does not liquefy gelatin, and it produces a permanent 
alkalinity in milk. The differential cultural reactions are shown in 
the table (page 35.3). 
1 Kendall, Day and Walker: .Jour. Am. Chem. Assn., 1913, 35, 1216. 
= Ibid., 1914, 36, 1940. 
3 British Med. Jour., 1916, ii, 893. 
