BACILLI OF THE COLON-TYPHOID-DYSENTERY GROUP 631 



Cultures of the colon bacillus arc characterized by a peculiar fetid 

 odor which is not unlike that of diluted feces. The acids formed by the 

 colon bacillus from sugars are chiefly lactic, acetic, and formic. The 

 gas it produces consists chiefly of CC>2 and hydrogen. The bacillus 

 grows well on media containing urine and on those containing bile. 

 Upon the latter fact methods for the isolation of the colon bacillus from 

 water and feces have been based. 



Isolation of the colon bacillus from mixed cultures is most easily 

 accomplished by plating upon lactose-litmus-agar, the Conradi-Drigal- 

 ski medium, or the Endo medium after preliminary enrichment if 

 necessary in bile or malachite-green broth. (In the case of feces such 

 enrichment is superfluous.) 



Distribution. The colon bacillus is a constant inhabitant of the 

 intestinal canal of human beings and animals. It is also found occasion- 

 ally in soil, in air, in water, and in milk and is practically ubiquitous in 

 all neighborhoods which are thickly inhabited. When found in nature 

 its presence is generally taken to be an indication of contamination from 

 human or animal sources. Thus, when found in water or milk, much 

 hygienic importance is attached to it. Recently, Papasotiriu 3 and 

 independently of him, Prescott, 4 have reported finding bacilli apparently 

 identical with Bacillus coli upon rye, barley, and other grains. They 

 believe, upon the basis of this discovery, that Bacillus coli is widely 

 distributed in nature and that its presence, unless it appears in large 

 numbers, does not necessarily indicate recent fecal contamination. 

 These reports, however, have not found confirmation by the work of 

 others. 



In man, Bacillus coli appears in the intestine normally soon after 

 birth, at about the time of taking the first nourishment. 5 From this 

 time on, throughout life, the bacillus is a constant intestinal inhabitant 

 apparently without dependence upon the diet. Its distribution within 

 the intestine, according to Gushing and Livingood, 6 is not uniform, it 

 being found in the greatest numbers at or about the ileocecal valve, 

 diminishing from this point upward to the duodenum and downward as 

 far as the rectum. Adami 7 and others claim that, under normal con- 

 ditions, the bacillus may invade the portal circulation, possibly by the 



3 Papasotiriu, Arch. f. Hyg., xli. 



4 Prescott, Cent. f. Bakt., Eef., xxxiii, 1903. 



* Schild, Zeit. f. Hyg., xix, 1895; Lemblce, Arch. f. Hyg., xxiv, 1896. 

 *Cushing and Livingood, "Contributions to Med. Sci. by Pupils of Wm. 

 Welch," Johns Hopk. Press, 1900. 



7 Adami, Jour, of Amer. Med. Assn., Dec., 1899. 



