564 Micro-organisms of the Plague Group 



Bacillus Cholera Gallinarum (Perroncito) ; Bacillus 

 Cholera; Bacillus Avicidum; Bacillus Avi- 

 SEPTicus; Bacillus of Rabbit Septi- 

 cemia; Bacillus CuNicxn-icroA 



General Characteristics. — A non-motile, non-flagellated, non-sporogenpus, 

 non-liquefjang, non-chromogenic, aerobic bacillus, pathogenic for birds and 

 mammals, staining by the ordinary methods, but not by Gram's nethod, pro- 

 ducing acids, indol, and phenol, and coagulating milk. 



The barnyards of both Europe and America are occasionally visited by an 

 epidemic disease known as "chicken-cholera," Buhnercholera, or cholera de poule, 

 which rapidly destroys pigeons, turkeys, chickens, ducks, and geese. Rabbit- 

 warrens are also at times affected and the rabbits killed. 



The bacillus responsible for this disease was first observed by Perroncito* 

 in 1878, and afterward thoroughly studied by Toussaint and Pasteur.t 



Morphology. — The organisms are short and bioad, with rounded ends, measur- 

 ing I X 0.4 to 0.6 n, sometimes joined to produce chains. Pasteur at first 

 regarded them as diplococci, because the poles stain intensely, a narrow space 

 between them remaining almost uncolored. This peculiarity is very marked, 

 and careful examination is required to detect the intermediate substance. The 

 bacillus does not form spores, is not motile, and has no flagella.J 



Staining. — The organism stains with ordinary anilin dye solutions, but not by 

 Gram's method. 



Cultivation. — Colonies. — Colonies upon gelatin plates appear after about two 

 days as small, irregular, white points. The deep colonies reach the surface slow- 

 ly, and do not attain to any considerable size. The gelatin is not liquefied. The 

 colonies appear under the microscope as irregularly rounded yellowish-brown 

 disks with distinct smooth borders and granular contents. Sometimes there is a 

 distinct concentric arrangement. 



Gelatin. — In gelatin puncture cultures a delicate white line occurs along the 

 entire path of the wire. Upon the surface the development is much more marked, 

 so that the growth resembles a nail with a good-sized flat head. If the bacUli be 

 planted upon the surface of obliquely solidified gelatin, a much more pronounced 

 growth takes place, and along the line of inoculation a dry, granular coating is 

 formed. There is no liquefaction of the medium. 



Bouillon. — The growth in bouiUon is accompanied by a slight cloudiness. 



Agar. — This growth, like that upon agar-agar and blood-serum, is white, 

 shining, rather luxuriant, and devoid of characteristics. 



Potato. — Upon potato no growth occurs except at 37°C. It is a very insig- 

 nificant, yellowish-gray, translucent film. 



Milk is acidulated and slowly coagulated. 



Vital Resistance. — The bacillus readily succumbs to the action of heat and 

 dryness. The organism is an obligatory aerobe. 



Metabolic Products. — Indol and phenol are formed. Acids are produced in 

 sugar-containing media, without gas formation. 



Pathogenesis.^ — The introduction of cultures of this bacillus into chickens, 

 geese, pigeons, sparrows, mice, and rabbits is sufficient to produce fatal septice- 

 mia. Feeding ^hickens, pigeons, and rabbits with material infected with the 

 bacillus is also sufficient to produce the disease. Guinea-pigs, cats, and dogs 

 seem immune, though they may succumb to large doses if given intraperitoneally. 

 The organism is probably harmless to man. 



Fowls ill with the disease fall into a condition of weakness and apathy, which 

 causes them to remain quiet, seemingly almost paralyzed, and the feathers rufiled 

 up. The eyes are closed shortly after the illness begins, and the birds gradually 

 fall into a stupor, from which they do not awaken. The disease is fatal in from 

 twenty-four to forty-eight hours. During its course there is profuse diarrhea, 

 with very frequent fluid, slimy, grayish-white discharges. 



* "Archiv. f. wissenschaftliche und praktische ThierheUkunde," 1879. 

 t " Compte-rendu de I'Acad. de Sci. de Paris," vol. xc. 

 % Thoinot and Masselin assert that the organism is motile. " Pr6cis de Mi- 

 crobie," 2d ed., 1893. 



