HEMORRHAGIC SEPTICEMIA GROUP IQI 



of affected persons a distinctive bacillus which has conformed 

 to all the conditions necessary to make it the cause of the 

 disease. 



Origin. In the tissues and all the body-fluids and secre- 

 tions of affected individuals. 



Form. Short, thick rods with an indistinct capsule and 

 rounded ends. Growing in chains in fluid media (Fig. 96) . 



Properties. Immotile. Stains readily. No spores. Cul- 

 tivated best in oxygen, but is facultative anaerobic. Stains 

 stronger at the ends, producing bipolar appearance. Gela- 

 tin not liquefied. Easily destroyed by sunlight and drying. 

 Very resistant to cold. 



Growth. Best at 30 C. ; aerobic, 



Gelatin. At 22 C., in twenty-four hours, white, point- 

 like colonies on the plates, with broad and flat surface, turn- 

 ing gray and then brown. Milk not curdled; slightly acid. 



Stab. Snow-white, spreading out on the surface to the 

 edge, and fluorescent. 



Bouillon. Granular precipitate, with clear fluid above. 

 When covered with oil and kept at rest, filaments hang down 

 from surface like stalactites. 



A gar and Blood-serum. Glass-like colonies like drops of 

 dew at first, then growing larger with iridescent edges. 



Potato. At 37 C. small white mass. Slow growth. 



No gas formation in glucose media. 



Staining readily with all basic dyes. Gram negative. 

 Capsule found in agar growths. 



Pathogenesis. After subcutaneous injection in rats death 

 follows in forty to sixty hours, with symptoms of severe toxe- 

 mia and convulsions. The point of infection shows a local 

 edema and inflammation of the lymphatics. All the organs 

 congested and surrounded by a bloody exudate. The charac- 

 teristic bacilli in all the tissues and secretions. Nearly all the 

 domestic animals are susceptible. Mosquitos and pigeons, 

 however, are immune flies are not; fleas are a very impor- 

 tant element in the transmission, and the rat-flea may com- 

 municate the disease to the rat from man or from the rat to 



