CHAPTER XXXIX 



THE BACnil OF THE HEMORRHAGIC SEPTICEMIA GROUP 

 AND BACILLUS PESTIS. 



In many of the lower animals there occur violently acute bacterial 

 infections characterized by general septicemia, usually with petechial 

 hemorrhages throughout the organs and serous membranes and severe 

 intestinal inflammations. These diseases, spoken of as the "hemor- 

 rhagic septicemias," are caused by a group of closely allied bacilli, first 

 classified together by Hueppe '■ in 1886. Some confusion has existed 

 as to the forms which should be considered within Hueppe's group of 

 "hemorrhagic septicemia," a number of bacteriologists including in 

 this class baciUi such as LoefHer's BacilLus typhi murium, and Salmon 

 and Smith's hog-cholera bacillus, microorganisms which, because of 

 their motility and cultural characteristics, belong more properly to the 

 "Gartner." " enteritidis," or "paratyphoid" group, intermediate be- 

 tween colon and typhoid. 



The organisms properly belonging to this group are short baciUi, more 

 plump than are those of the colon type, and showing a marked ten- 

 dency to stain more deeply at the poles than at the center. They are 

 non-motile, possess no flagella, and do not form spores. They grow 

 readily upon simple media, but show a very marked preference for 

 oxygen, growing but slightly below the surface of media. By some 

 observers they are characterized as " obligatory aerobes," but this is 

 undoubtedly a mistake. 



While showing considerable variations in form and differences in 

 minor cultural characteristics, the species characteristics of polar stain- 

 ing, decolorization by Gram, immobility, lack of gelatin liquefaction, 

 and great pathogenicity for animals, stamp alike all members of the 

 group. Its chief recognized representatives are the bacillus of chicken 

 cholera, the bacillus of swine-plague (Deutsche Schweineseuche), 



' Hueppe, Berl. klin. Wocfi., 1886. 

 551 



