Bacillus Cholerae Gallinarum, Perroncito, Pasteur (1880). 



CHICKEN OE FOWL CHOLERA; CHOLERA DES POULES {-Fr.); 

 HUHNEE-,GEFLUGEn>-CHOLERA (Oerm.). 



Origin. — In the blood, org'ana and excreta of chickens which have 

 the disease. A somewhat similar disease of chickens, occurring in 

 Russia, has been shown to be due to the Vibrio Metchnikovi which 

 resembles very closely the vibrio of Asiatic cholera. A similar, if 

 not identical organism has been isolated by Koch from water and de- 

 signated as the B. of rabbit septicemia. 



Form. — Small short rods which have rounded ends and are fre- 

 quently in pairs, rarely in long threadsv At times the form is almost 

 that of a coccus. 



Motility.— It has no motion. 



Sporulation. — Spores have not been observed. Nevertheless, it 

 possesses considerable power of resistance and can withstand the 

 acidity of the gastric juice. 



Aniijn dyes. — Usually stain the ends first while the center re- 

 mains uncolored — bi-polar stain. The appearance then is that of a 

 diplococcus. On more intense staining the entire rod becomes col- 

 ored. Gram's method is not applicable. 



Growth." Is rather slow. 



/V«^^j.— Colonies appear in a few days on gelatin plates as%iinute white dots which, 

 under the microscope, are seen to be roundish plates with sharp, smooth borders. The 

 contents are finely granular, show concentric rings and are yellowish in color. No lique- 

 faction. * 



Siab culture. — Forms in gelatin, a delicate white line or row of dots along the line of 

 inoculatiop. On the surface it forms a delicate whitish growth which spreads very slowly. 



Streak culture. — On agar it develops as a thick, glistening, grayish-white mass. No 

 growth on potato at ordinary temperature, but in the incubator in a few days it gives rise 

 to a yellowish-gray. transparent wax-like covering. 



Bouillon. — Diffuse cloudiness and a slight deposit. Indol is formed. 



Milk. — Is slowly coagulated — acid production. 



Oxygen requirements. — Is a facultative anaerobe. ^ 



Temperature. — Grows at ordinary temperature and also in the 

 incubator. 



Behavior to gelatin. — Does not liquefy. 



Attenuation. — Artificial cultures soon lose their virulence. The 

 virulence can be increased remarkably by successive passage through 

 animals, and by the coUodium sac method. In sealed tubes (Figs. 61, 

 62) the virulence is preserved. 



Immunity. — Is produced in chickens and pigeons by inoculation 

 with first and second vaccines. It was in connection with this dis- 

 ease that vaccination by means of attenuated cultures was discovered 

 (Pasteur, 1880). 



Pathogenesis. — Chickens, geese, pigeons, sparrows, mice and rab- 

 bits are susceptible, to subcutaneous inoculation. Guinea-pigs, sheep, 

 horses are less susceptible and only local abscesses form. Dogs and 

 cats are immune. After death the bacilli are found distributed 

 throughout the body — a true septicemia. 



Infection. — Usually results in chicken through the food. It may 

 possibly occur through scratches and wounds. 



Diagnosis. — Stained preparations of the blood (p. 281) will show 

 the typical short rods in enormous numbers. Absence of motion, the 

 behavior to milk, etc., and the animal experiment will distinguish it 

 from similar organisms. 



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