Pathogenesis 625 



The Spirillum of Gamaleia* (Spirillum Metchnikovi) 



Resembling the cholera spirillum in morphology and vegetation, and possibly, 

 as has been suggested, a descendant of the same original stock, is a spirillum 

 which GamaUia cultivated from the intestines of chickens affected with a disease 

 similar to chicken-cholera. 



Morphology. — This spirillum is a trifle shorter and thicker than the cholera 

 spirillum. It is a littlemore curved, and has similar rounded ends. It forms 

 long spirals in appropriate media, and is actively motile. Each spirillum is 

 provided with a terminal flagellum. No spores have been demonstrated. 



Staining. — The organism stains easily, the ends more deeply than the center. 

 It is not stained by Gram's method. 



Cultivation. — It grows well both at the temperature of the room and at that of 

 incubation. 



Colonies. — The colonies upon gelatin plates have a marked resemblance to 

 those of the cholera spirUlum, yet there is a difference; and as Pfeiffer says, " it 

 is comparatively easy to differentiate between a plate of pure cholera spirillum 

 and a plate of pure Spirillum metchnikovi, yet it is almost impossible to pick out 

 a few colonies of the latter if mixed upon a plate with the former." 



Frankel regards this organism as a species intermediate between the cholera, 

 and the Finkler-Prior spirillum. 



The colonies upon gelatin plates appear in about twelve hours as small whitish 

 points, and rapidly develop, so that by the end of the third day large saucer- 

 shaped liquefactions resembling colonies of the Finkler-Prior spirillum occur. 

 The liquefaction of the gelatin is quite rapid, the resulting fluid being turbid. 

 Usually, upon a plate of Vibrio metchnikovi some colonies are present which 

 closely resemble those of the cholera spirillum, being deeply situated in conical 

 depressions in the gelatin. Under the microscope the contents of the colonies, 

 which appear of a brownish color, are observed to be in rapid motion. The edges 

 ■of the bacterial mass are fringed with radiating organisms. 



Gelatin Punctures. — In gelatin tubes the growth closely resembles that of the 

 cholera organism, but develops more slowly. 



Agar-agar. — Upon the surface of agar-agar a yellowish-brown growth develops 

 along the whole line of inoculation. 



Potato. — On potato at the room temperature no growth occurs, but at the 

 temperature of the incubator a luxuriant yellowish-brown growth takes place. 

 Sometimes the color is quite dark, and chocolate-colored potato cultures are not 

 uncommon. 



Botullon. — In bouillon the growth which occurs at the temperature of the incu- 

 bator is quite characteristic, and very different from that of the cholera spirillum. 

 The entire medium becomes clouded, of a grajdsh-white color, and opaque. A 

 folded and wrinkled pellicle forms upon the surface. 



Milk. — When grown in litmus milk, the original blue color is changed to pink 

 in a day, and at the end of another day the color is all destroyed and the milk 

 coagulated. Ultimately the clots of casein sediment in irregular masses, from 

 the clear, colorless whey. 



Vital Resistance. — The organism, like the cholera vibrio, is very susceptible to 

 the influence of acids, high temperatures, and drying. The thermal death-point 

 is So°C., continued for five minutes. 



Metabolic Products. — The addition of sulphuric acid to a culture grown in a 

 medium rich in peptone produces the same rose color observed in cholera cultures 

 and shows the presence of nitroso-indol. When glucose is added to the bouillon 

 no fermentation or gas-production results. The organism produces acids and 

 ■curdling enzymes. 



Pathogenesis. — The organism is pathogenic for animals, but not for man. 

 Pfeiffer has shown that chickens and guinea-pigs are highly susceptible, and when 

 inoculated under the skin usually die. The virulent organism is invariably fatal 

 for pigeons. W. Rindfleisch has pointed out that this constant fatality for 

 pigeons is a valuable criterion for the differentiation of this spirillum from that 

 •of cholera, as the subcutaneous injection of the most virulent cholera cultures is 

 never fatal to pigeons, the birds only dying when the injections are rnade into the 

 muscles in such a manner that the muscular tissue is injured and becomes a locus 

 ininoris resistentia. When guinea-pigs are treated by Koch's method of narco- 



* "Ann. de I'Inst. Pasteur," 1888. 

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