BACILLUS CAPSULATUS 227 



THE DRUMSTICK BACTERIA. 



(Ger. Trommelschlagerbacillen. ) 



This is a group of saprophytic organisms which form spores at the end 

 of the bacillus, which thus acquires the form of a drumstick. (See Photo- 

 micrograph, Fig. 82.) These bacilli are widely distributed organisms. 



Microscopical Appearances. Very small rods, strongly motile. 



Gelatine Media are liquefied. 



Grether describes a variety that is non-motile,, and does not liquefy 

 gelatine. 



BACILLUS CAPSULATUS (PFEIFFER). 



Pfeiffer isolated the organism from a purulent exudate found in 

 the peritoneal cavity of a dead guinea-pig, also present in the blood. 



Microscopical Appearances. It is a plump bacillus with rounded 

 ends, possessing a well-defined ovoid capsule. 



Motility. Non-motile. 



Spore Formation has not been confirmed. 



Staining Reactions. The reaction with the Gram method is 

 negative ; the capsules are easily demonstrated when stained by Johne's 

 method. (See Techniqne, 22.) 



Biological Characters. Facultative anaerobe growing on the 

 ordinary nutrient media, better at 37 C. than at ordinary room 

 temperature. 



In Gelatine Stab Cultures a slimy, white, nail-formed growth develops, 

 and an inodorous gas is formed ; the gelatine is not liquefied. 



On the Surface of A gar it forms a thick, moist, white viscid coating. 



On Potatoes, a yellowish-white viscid covering. 



Pathogenesis. White and house mice inoculated subcutaneously 

 die in from two to three days. The spleen of the dead animals is found 

 greatly enlarged, and the bacilli are present in the blood and organs, 

 with well-defined capsules. Guinea-pigs, pigeons, and rabbits are also 

 susceptible, guinea-pigs and pigeons only by intraperitoneal infection, 

 and rabbits only when large quantities of the culture are introduced intra- 

 venously. The bodies of the dead animals undergo putrefactive changes 

 very quickly. The blood and tissue juices exhibit a stringy consistence. 



