SPIRILLUM METCHNIKOVI. 427 



be specially noted, the test for the cholera-red reaction should 

 be applied, and in many cases it is advisable to test the effects 

 of intraperitoneal injection of a portion of a recent agar culture 

 in a guinea-pig, the amount sufficient to cause death being also 

 ascertained. The agglutinating or sedimenting properties of the 

 serum of the patient should be tested against a known cholera 

 organism, and against the spirillum cultivated from the case. In 

 the same way the action of the serum of an immunised guinea- 

 pig may be tested both as regards agglutinating and protective 

 properties. 



A number of other spirilla have been cultivated, which are of 

 interest on account of their points of resemblance to the cholera 

 organism, though probably they produce no pathological condi- 

 tions in the human subject. 



Metchnikoff's Spirillum (vibrio Metchnikovi) . This organism was ob- 

 tained by Gamaleia from an epidemic disease of fowls in Odessa, and is of 

 special interest on account of its close 



resemblance to the cholera organism. ^f,y\ V 



In the natural disease, which especially ' > > * A .* 



affects young fowls, the animals suffer * i ^ JS 



from diarrhrea, pass into a sort of 

 stupor, sitting with their feathers 

 ruffled, and usually die within forty- 

 eight hours. The intestines contain 

 a greyish-yellow fluid, sometimes 

 slightly blood-stained, in which the 

 spirilla are found. A few of these 

 spirilla may also be found in the 

 blood in the younger fowls, though 

 generally absent from the blood in 

 the older. 



Morphologically the organism is FIG. 143. Metchnikoff's spirillum, both 



practically identical with Koch's spiril- in , curved f and str f aigh < forms ; fro an agar 

 3 F culture of twenty-four hours growth. 



lum (Fig. 143). It is actively motile, stained with weak carbol-fuchsin. x TOCO. 

 and has the same staining reactions. 



Its growth in peptone gelatin also closely resembles that of the cholera organ- 

 ism, though it produces liquefaction more rapidly (Fig. 144, A). In gelatin 

 plates the young colonies are, however, smoother and more circular. After 

 liquefaction occurs, some of the colonies are almost identical in appearance with 

 those of the cholera organism, whilst others show more uniformly turbid con- 

 tents. In puncture cultures the growth takes place more rapidly, but in ap- 

 pearance closely resembles that of the cholera organism a few days older. Its 

 growth in peptone solution, too, is closely similar, and it also gives the cholera- 

 red reaction. 



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