44o 



PATHOGENIC BACTERIA. 



The Spirillum of Denecke 1 (Vibrio Tyrogenum). — 



Another organism with a distinct resemblance to the 

 cholera spirillum is one described by Denecke as occur- 

 ring in old cheese (Fig. 95). Its form is much the same 

 as that of the spirillum of cholera, the shorter indi- 

 viduals being of equal diameter throughout. The spirals 

 which are produced are longer than those of the Finkler 

 and Prior spirillum, and are more tightly coiled than 

 those of the cholera spirillum. 



Like its related species, this micro-organism is actively 

 motile. It grows at the room-temperature, as well as at 

 37 C, in this respect, as in its reaction to stains, much 

 resembling the other two. 



Upon gelatin plates the growth of the colonies is much 

 more rapid than that of the cholera spirillum, but slower 

 than that of the Finkler and Prior spirillum. The col- 



FiG. 95. — Spirillum Denecke, from an agar-agar culture; x 1000 (Itzerott 

 and Niemann). 



onies appear as small whitish, round points, which soon 

 reach the surface of the gelatin and commence liquefac- 

 tion. By the second day they are about the size of a 

 pin's head, have a yellow color, and occupy the bottom 

 of a conical depression. The appearance is much like 

 that of a plate of cholera spirilla. 



1 Deutsche med. Wochenschrift, 1 885. 



