ANTHRAX 



75 



(2) Nonmotile. 



B. aerogenes capsulatus, B. phlegmonis emphysematosse (Frankel) or 

 B. perfringens. 



SPORE-BEARING AEROBES 



Bacillus anthracis (Pollender discovered 1849. Davaine recognized 

 nature 1863. Koch proved 1876). Of the aerobic_spore-bearing 

 bacilli this is the only one of particular medical importance"" 



Anthrax is an important disease in domesticated animals, especially sheep andcattle. 

 The characteristic postmortem change in animals is the greatly enlarged, friable, 

 mushy gpleen. Man is much less susceptible than these animals, but is more so 

 than the goat, horse, or pig. The 41gerian^sheep has a high degree of immunity, 



FIG. 17. Anthrax bacilli. Cover-glass has been pressed on a colony and then fixed 

 and stained. (Kolle and Wassermann.) 



as has the white rat. The brown rat is quite susceptible as are also guinea-pigs, mice 

 and rabbits. The disease in man chiefly occurs among those working with hides, 

 wool, or meat of infected cattle. The two chief types in man are: i. Malignant 

 pustule and 2. Woolsorter's disease. An intestinal type is also recognized. 



Malignant pustule results from the inoculation of an abrasion or cut; 

 thus it frequently shows on the arms and the backs of those unloading 

 hides. It first appears as a pimple, the center of which becomes vesicu- 

 lar, then necrotic. 



A ring of vesicles surrounds this central eschar and a zone of congestion, the 

 vesicles. The lymphatics soon become inflamed as well as neighboring glands. 

 If the pustule is not excised andtleath occurs, there is not much enlargement of the 



