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BACILLUS COLI COMMUNIS. Escherich (1885). 



BACTERIUM COLI COMMUNE ', THE COLON BACILLUS OF ESCHERICH. 



Origin. Is very common and constant in the intes- 

 tinal contents of man and animals, especially in the colon; 

 occurs in the discharges of healthy infants, also in summer 

 diarrhoea. Is frequently present, accompanying the com- 

 ma bacillus, in the discharges of Asiatic cholera, and in 

 later stages may be the only organism present. In many 

 respects it resembles Emmerich's bacillus, and also the 

 typhoid fever bacillus. 



Form. Short, narrow rods ; may vary in length from 

 oval or coccus-like forms to rods 4-6 times as long as wide. 

 Usually grows in pairs, arranged in groups. 



Motility. Very slowly motile. 



Sporulation. Not observed. 



AnilinDyes. Stains readily; not by Gram's method. 



Growth. Is fairly rapid and the cultural properties 

 lesemble those of the preceding organism. 



Plates. On gelatin plates the surface colonies are flat, spreading, an- 

 isodiametric and have a dull-white color. The border is irregular and mark- 

 ings are present in the outer zone. No liquefaction. 



Stich Cultures. Rather energetic growth along the line of inoculation, 

 while on the surface it spreads as a delicate white film. 



Streak Cultures. On agar, are moist, white, spreading, as with the 

 Emmerich bacillus. On potatoes, it forms an abundant, yellowish, moist, 

 slowly spreading growth. 



Milk.Ls coagulated in 7- 10 days. 



Oxygen requirements. Is a facultative anaerobe. 



Temperature. Grows well at ordinary temperature. 

 Its optimum is about 37 0. 



Behavior to Gelatin. Does not liquefy. 



Aerogenesis. Under anaerobic conditions produces 

 carbonic acid and hydrogen. 



Pathogenesis. Guinea-pigs are very susceptible; 

 rabbits less so; mice insusceptible. Small quantities in- 

 jected subcutaneously or intravenously produce diarrhoea, 

 collapse and death in 1-3 days. The small intestine is 

 hyperaemic, more or less intensely inflamed ; serous exu- 

 viates may be present. The bacilli are abundant in the 

 blood and organs. 



