CHAPTER XXII. 



THE BACILLUS OF MALIGNANT EDEMA AND SIMILAR BACTERIA 



BACILLUS OF GASTROMYCOSIS OVIS BACILLUS 



AEROGENES CAPSULATUS. 



BACILLUS OF MALIGNANT EDEMA. 



Occurrence and Historical. A spore-forming anaerobic bacterium, 

 causing a peculiar form of wound infection and inflammation, fre- 

 quently occurs in soil, sewage, dust, grasses, the intestinal contents of 

 animals, manure, and putrefying animal substances. Feser, in 1876, 

 working with "Rauschbrand," evidently saw these bacilli, but they 

 were first more exactly recognized by Pasteur, who was able to 

 produce in guinea-pigs and rabbits by the inoculation of putrid 

 material a disease characterized by an edematous inflammation at the 

 place of inoculation. Pasteur named the bacterium which produced 

 these changes "Vibrion septique." Robert Koch, in 1881, showed 

 that this disease was not a true septicemia, and he called it malignant 

 edema and the microorganism the bacillus of malignant edema. Its 

 pathogenic significance was later studied by a number of observers, 

 including Brieger and Ehrlich, Jensen and Sand, Kitt, and others. 

 It has been found to be the cause of wound complications in man and 

 domestic animals, among the latter particularly in horses, cattle, and 

 sheep, very rarely in hogs, dogs, and cats. 



Pathologic Lesions. At the place of infection with the bacillus of 

 malignant edema the tissues are swollen and considerably infiltrated 

 with a yellowish or reddish serous exudate. The fluid contains 

 numerous gas-bubbles. Hemorrhages are found here and there in 

 the tissues. The peritoneal cavity contains a moderate amount of 

 reddish serous fluid; the peritoneum is congested, dull, but does 

 not show any fibrinous deposit. In cases where malignant edema 

 follows delivery the uterus is found to be flaccid and insufficiently 

 contracted; the wall of the uterus and the pelvic connective tissue 

 are edematous. The cotyledons, according to Carl, are changed 

 into a mushy, dirty, ill-smelling mass. The spleen, as a rule, is not 

 much changed, but it may be swollen, edematous, and emphysema- 

 tous. The liver shows parenchymatous degeneration, the lymph 

 nodes are swollen, the lungs are edematous and congested, and the 

 heart muscle is soft and flabby; the blood, as in anthrax, does not 

 promptly and firmly coagulate, and putrefactive changes set in early. 

 If juice from an emphysematous organ or location is examined 



