CHAPTER XV. 
THE ALC ALIGENES - DYSENTERY - TYPHOID - PARA- 
TYPHOID -MORGAN BACILLUS GROUP. 
BACILLUS ALCALIGENES. 
Bacillus alcaligenes was first isolated by Petriischkyi from the 
feces of a patient presenting the chnical symptoms of typhoid fever. 
The serum did not agglutinate the typhoid bacillus and no typhoid 
bacilli were recovered from the blood or dejecta. Several similar 
cases'- are now on record in which B. alcaligenes has been isolated both 
from the blood stream and the intestinal contents ; the sera from these 
cases agglutinated the specific organism in dilutions of 1 to 50 or even 
higher, and B. typhosus was not found. B. alcaligenes occurs occa- 
sionally in acute intestinal disturbances of young children, not infre- 
quently in association with organisms of the dysentery and paratyphoid 
groups.'' Less commonly it is found in the dejecta of normal children, 
adults^ and in water. It is also said to cause severe cases of pyelo- 
nephritis.'' 
Morphology.— The organism both in size and shape resembles the 
typhoid bacillus very closely. It is actively motile and has peritrichic 
flagella. It does not form spores, and so far as is known, does not 
exhibit a capsule. Ordinary anilin dyes color it readily and it fails to 
retain the Gram stain. 
Isolation and Cultures. —The organism grows readily in ordinary 
media. On agar the colonies are transparent, colorless and roiuid, 
and after eighteen hours' incubation at 87° C. attain a diameter of 
from 1 to 3 mm. The organism grows with moderate luxuriance on 
gelatin, but produces no liquefaction. In broth there is a uniform 
clouding, and after a few days a delicate pellicle usually forms. B. 
alcaligenes grows fairly readily in milk; the reaction becomes pro- 
gressively alkaline. In sugars no acid or gas is developed. 
The organism is aerobic, facultatively anaerobic. The minimum 
temperature of growth is about G° C, the optimum 37° C, and the 
maximum about 44° C. The resistance of B. alcaligenes to physical 
and chemical reagents is similar to that of the typhoid bacillus. 
Products of Growth. B. alcaligenes is characterized culturally by its 
inertness. Neither acid nor gas is produced from any known sugar. 
1 Centralbl. f. BakterioL, 1896, 19, 187. 
2 Flirth: Munchen. med. Wchnschr., 1913, 60, 2669. 
3 Kendall, Day and Bagg: Boston Med. and Surg. Jour., 1913, 169, 741. 
* Ford: Studies from the Royal Victoria Hospital, Montreal, 1903, 1, No. 5. 
5 Rochaix and Blanchard: Ann, de med-, 1920, 8, 173, 
