624 Spirillum of Denecke 



a coiled mass. Upon the surface a delicate, imperfect, 

 yellowish scum forms. Liquefaction of the entire gelatin 

 generally requires about two weeks. 



Agar-agar. Upon agar-agar this spirillum forms a thin 

 yellowish layer which spreads quickly over most of the sur- 

 face. 



Bouillon. In bouillon the growth of the organism is 

 characterized by a diffuse turbidity. No gas-formation 

 occurs in sugar-containing media. 



Fig. 217. Spirillum of Denecke; gelatin puncture cultures aged forty- 

 eight and sixty hours (Shakespeare). 



Potatoes. The culture upon potato is luxuriant if 

 grown in the incubating oven. It appears as a distinct 

 yellowish, moist film, and when examined microscopically 

 is seen to contain beautiful long spirals. 



Metabolic Products. The organism produces no indol. 



Pathogenesis. The spirillum of Denecke is mentioned 

 only because of its morphologic resemblance to the cholera 

 spirillum. It is not associated with any human disease. 

 Experiments, however, have shown that when the spirilla 

 are introduced into guinea-pigs whose gastric contents are 

 alkalinized and whose peristalsis is paralyzed with opium, 

 about 20 per cent, of the animals die. 



