CHAPTER XVI. 



THE ALCALIGENES DYSENTERY TYPHOID PARA- 

 TYPHOID GROUP. 



BACILLUS ALCALIGENES. 



BACILLUS alcaligenes was first isolated by Petruschky 1 from the feces 

 of a patient presenting the clinical 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 Bacillus alcaligenes has been isolated both 

 from the blood stream and the intestinal contents; the sera of these 

 cases agglutinated the specific organism in dilutions of 1 to 50 

 or even higher, and Bacillus typhosus was not found. Bacillus 

 alcaligenes occurs occasionally in acute intestinal disturbances of 

 young children, not infrequently in association with organisms of the 

 dysentery and paratyphoid groups. 2 Less commonly it is found in 

 the dejecta of normal children, adults 3 and in water. 



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 round, 

 and after eighteen hours' incubation at 37 C. attain a diameter of 

 from 1 to 3 mm. The organism grows with moderate luxuriance on 

 gelatin, but produces no liquefaction. In broth theie is a uniform 

 clouding, and after a few days a delicate pellicle usually forms. Bacillus 

 alcaligenes grows fairly readily in milk; the reaction becomes progres- 

 sively alkaline. In sugars no acid or gas is developed. 



The organism is aerobic, facultatively anaerobic. The minimum 

 temperature of growth is about 6 C., the optimum 37 C., and the 



1 Cent. f. Bakt., 1896, xix, 187. 



2 Kendall, Day and Bagg, Boston Med. and Surg. Jour., 1913, clxix, 741. 



3 Ford, Studies from the Royal Victoria Hospital. Montreal, 1903, i, No. 5. 



