108 ESSENTIALS OF BACTERIOLOGY. 



Staining. Do not take Gram. Fuchsin stains them easily. 



Pathogenesis. When large quantities injected into guinea- 

 pigs, they die at times, sometimes with intestinal symptoms, 

 sometimes without. 



Bacillus Coli Communis. (Eseherich.) 



Found in human feces, intestinal canal of most animals, in 

 pus and water. 



Form. Short rods with very slow movement, often associated 

 in little masses resembling the typhoid germ. 



Properties. Does not liquefy gelatine, causes fermentation in 

 saccharine solutions in the absence of oxygen, produces acid 

 fermentation in milk. 



Growth. On potato a thick, moist, yellow-colored growth. 

 Very soon after inoculation on gelatine a growth similar to 

 typhoid. It can also develop in carbolized gelatine, and with- 

 stands a temperature of 45 C. without its growth being de- 

 stroyed. 



Pathogenesis. Inoculated into rabbits or guinea-pigs, death 

 follojvs in from one to three days, the symptoms being those 'of 

 diarrhoea and coma ; after death tumefactions of Peyer's patches 

 and other parts of the intestine ; perforations into peritoneal 

 cavity, the blood containing a large number of germs. 



Staining. Ordinary stains; do not take Gram. 



Site. The bacillus has been found very constant in acute 

 peritonitis and in cholera nostra. Its presence in water would 

 indicate fecal contamination. 



The growth on potato, the effect on animals, and its action to- 

 wards milk are points of difference from the typhoid bacillus. 



