34 



MAX LEVINE 



TABLE 15 



FERMENTATION OF SUCROSE BY BACILLUS-COLI-LIKE BACTERIA FROM HUMAN FECES 



been obtained by previous investigators. In Table 15 is shown the pro- 

 portion of sucrose-fermenters obtained from human feces by different 

 investigators. Howe 10 found 60% of 540 Bacillus-coli-like organisms 

 to be sucrose fermenters, but the other investigators usually found 

 twice as many nonfermenters as fermenters. Of 2601 cultures of 

 human colon bacilli studied by various observers, at different times 

 and in different countries, only 35.3% fermented sucrose. 



In connection with the study reported here it should be noted that 

 the number of human strains isolated is small, and that they were col- 

 lected in the winter. Clemesha, 13 and also Browne, 1 call attention to 

 "epidemics" of certain types of B. coli, and to seasonal variations. 

 These phases need further investigation. 



CONCLUSIONS 



In studies on quantitative acid-production the average should be 

 supplemented with a statement of its deviation measures ; the unquali- 

 fied average may lead to a misconception of the acid-producing prop- 

 erties of a group of organisms. 



Quantitative acid-production in glucose, galactose, maltose, lactose, 

 sucrose, raffinose, salicin, inulin, mannitol, dulcitol, and glycerol, is not 

 a reliable index for differentiating colon-bacillus-like bacteria derived 

 from pig, horse, sheep, cow, or man. 



The MacConkey types are indistinguishable on the basis of quan- 

 titative acid-production in the fermentable carbohydrates, the alcohols, 

 and the glucosid studied. 



* Science, 1912, 35, p. 225. 



11 Suppl. to 32nd Ann. Rep. containing Rep. of Med. Officer for 1902-1903, p. 511. 



12 Arch. d. Real Inst. Bacteriol. Camara Pestana, 1908, 2, p. 153. 

 Jour. Hyg., 1912, 12, p. 463. 



