DENEKE'S SPIRILLUM 



419 



X 4 .t 



in two or three days has formed a slimy layer of greyish-yellow colour, 

 which rapidly spreads over the potato. On all the media the growth 

 has a distinctly fcetid odour. A growth in peptone solution fails to give 

 the cholera-red reaction at the end of twenty-four hours, though later a 

 faint reaction may ap - 

 pear. As stated above, Koch 

 succeeded in producing, 

 by this organism, an intes- 

 tinal affection inguinea-pigs 

 after neutralising the stom- 

 ach contents and paralysing 

 the intestine with opium. 

 This occurs in a small pro- 

 portion of the animals ex- 

 perimented on, and the con- ^ r v 

 tents of the intestine, unlike 

 what was found in the case 

 of the cholera organism, ^j 

 were turbid in appearance, 

 and had a markedly foetid 

 odour. When tested by in- 

 traperitoneal injection, its 

 effects are somewhat of the 

 same nature as those of the 



'V 



; ^L I 



\ 



FIG. 141. Finkler and Prior's spirillum ; from 

 an agar culture of twenty - four hours' 

 growth. 

 Stained with carbol-fuchsin. x 1000. 



cholera organism, but its 

 virulence is of a much lower 

 order. 



An organism cultivated by 

 Miller (" Miller's Spirillum") 

 from the cavity of a decayed 

 tooth in a human subject is almost certainly the same organism as 

 Finkler and Prior's spirillum. 



Deneke's Spirillum. This organism was obtained from old cheese, and 

 is also known as the spirillum tyrogenum. It closely resembles Koch's 

 spirillum in microscopic appearances, though it is rather thinner and 

 smaller. Its growth in gelatin is also somewhat similar, but liquefaction 

 proceeds more rapidly, and the bell-shaped depression on the surface is 

 larger and shallower, whilst the growth has a more distinctly yellowish 

 tint. The colonies in plates also show points of resemblance, though the 

 youngest colonies are rather smoother and more regular on the surface, and 

 liquefaction occurs more rapidly than in the case of the cholera organism. 

 The colonies have, on naked-eye examination, a distinctly yellowish colour. 

 The organism does not give the cholera-red reaction, and on potato it 

 forms a thin yellowish layer when incubated above 30 C. When tested 

 by intraperitoneal injection and by other methods it is found to possess 

 very feeble, or almost no, pathogenic properties. Koch found that this 

 organism, when administered through the stomach in the same way as 

 the cholera organism, produced a fatal result in three cases out of 

 fifteen. Deneke's spirillum is usually regarded as a comparatively 

 harmless saprophyte. 



