ANAEROBIC BACTERIA 



185 



Properties. Very motile; liquefies gelatin; gas is produced 

 in cultures but very little in the body. 



Growth. Grows rapidly, but only when the air is excluded, 

 and best in incubator at 37 C. 



Roll Cultures (After Esmarch's 

 Method). Small, round colonies with 

 fluid contents, under low power, a mass 

 of motile threads in the center, and at 

 the edges a wreath-like border. 



High Stab-culture. With glucose 

 gelatin, the growth at first seen in the 

 bottom of the tube, with a general 

 liquefaction of the gelatin; gases de- 

 velop and a somewhat unpleasant odor. 



A gar. The gases develop more 

 strongly in this medium, and the odor 

 is more prominent. 



Guinea-pig Bouillon. In an atmos- 

 phere of hydrogen clouding of the en- 

 tire culture-medium without any floc- 

 culent precipitate until third day. Milk 

 coagulated. Glucose media marked gas 

 fermentation. 



Staining. Are stained with the ordi- 

 nary dyes, but Gram's method negative. 



Pathogenesis. When experiment ani- 

 mals, mice or guinea-pigs, are injected 

 with a pure culture under the skin, they 

 die in eight to fifteen hours, and the 

 following picture presents itself at the 

 autopsy : In guinea-pigs from the point 

 of infection, spreading over a large area, 

 an edema of the subcutaneous tissues 

 and muscles, which are saturated with 

 a clear red serous exudate, free from odor, and containing 

 great quantities of bacilli. 



The spleen is enlarged, especially in mice. The bacilli are 



Fig. 93. Bacillus 

 of malignant edema 

 growing in glucose- 

 gelatin (Frankel and 

 Pfeiffer). 



