METCHNIKOFFS SPIRILLUM 4V7 



the disease is endemic, and that its direct cause is Koch's spirillum 

 with the characters described above. 



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 con- 

 ditions in the human subject. 



Metchnikoffs Spirillum (vibrio Metchnikovi). This organism was 

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

 of special interest on account 



of its close resemblance to n^sV ^ 



the cholera organism. ^ * JfJi*\* * 



Morphologically the organ- ^,*f '%* *\ 



ism is practically identical *>*!, 



with Koch's spirillum (Fig. 

 140). It is actively motile, 

 and has the same staining 

 reactions. Its growth in 

 peptone-gelatin also closely 



resembles that of the cholera tf %*. -'Sji^f] V*5C* N y< * T" 



organism, though it produces ' L**Vx f^ffp \**/ \e*^ 1*1 j 

 liquefaction more rapidly Vi^l jj** t^ 



(Fig. 141, A). After lique- ^XiT N*L <^ V M *. 

 faction occurs, some of the -0 % ^ ->lw 1 * 



colonies are almost identical ^ ^^<^ *^i 



in appearance with those of 



the cholera vibrio, whilst * *' 



others show more uniformly ~_ **$ * 



turbid contents. In punc- 

 ture cultures the growth FlG - 140. Metchnikoffs spirillum, both m 

 takes place more rapidlv curved and straight forms ; from an agar 



1 culture of twenty-four hours' growth. 



but in appearance closely re- Stained with weak carbol-fuchsin x 1000 

 sembles that of the cholera 

 organism a few days older. 



Its growth in peptone solution, too, is closely similar, and it also give's 

 the cholera-red reaction. 



This organism can, however, be readily distinguished from the cholera 

 organism by the effects of inoculation on animals, especially on pigeons 

 and guinea-pigs. Subcutaneous inoculation of small quantities of pure 

 culture in pigeons is followed by septicaemia, which produces a fatal result 

 usually within twenty-four hours. Inoculation with the same quantity 

 of cholera culture produces practically no result ; even with large quantities 

 death is rarely produced. The vibrio Metchnikovi produces somewhat 

 similar effects in the guinea-pig to those in the pigeon, subcutaneous 

 inoculation being followed by extensive hsemorrhagic cede ma and a rapidly 

 fatal septicaemia. Young fowls can be infected by feeding with virulent 

 cultures. We have evidence from the work of Gamaleia that the toxins 

 of this organism have somewhat the same action as those of the cholera 

 organism. 



The organism is therefore one which very closely resembles the cholera 

 organism, the results on inoculating the pigeon offering the most ready 

 means of distinction. It gives a negative reaction to Pfeiffer's test that 

 is, the properties of an anti-cholera serum are not exerted against it. It 



