34 Maligaaat Edema. 



Probably there are also other bacteria capable of producing a dis- 

 ease resembling malignant edema. Thus, Novy observed the appear- 

 ance of a similar disease in guinea pigs following subcutaneous injec- 

 tions of milk nuclein, and he proved that an organism closely resembling 

 the above-described bacillus was the cause. However, it was somewhat 

 more slender and provided with strikingly long and thick flagella. It 

 is also an anaerobic but sporeless bacillus (Bac. oed. maligni .II). 

 Klein isolated from garden soil (Bac. oed. sporogenes) and Sanfelice 

 from guinea pigs inoculated with dirt containing putrid organic sub- 

 stances, a similar, although only facultative anaerobic, bacillus (Bac. oed. 

 aerogenes). According to Fraenkel the Bac. phlegmones emphysema- 

 tosffi produces in man a similar disease (gangrene foudroyante). On 

 the other hand, according to Kirsten the edema bacilli, like most of the 

 species of bacteria, form groups of varieties which may be distinguished 

 from 6ach other by their morphological and biological characteristics. 

 However, in their clinical relation the most important characteristic is 

 the absence of pathogenicity in most of the varieties. 



For natural infection of domestic animals solipeds are 

 most susceptible, vs^hile cattle, sheep and goats are less sus- 

 ceptible. Hogs, dogs and cats are rarely affected. 



The infection results in most instances from the entrance 

 of the edema bacillus into the deeper parts of the subcutaneous 

 or submucous tissue through breaks in the continuity of the 

 skin or the mucous membrane of the mouth and esophagus. 

 There are many opportunities for such infections as the bacilli 

 are widely disseminated in the dirt, especially in dust of hay, 

 in garden or field soil, in street dust, in household drainage, 

 in putrid organic material, and in excrement of healthy animals. 

 These substances are very prone to come in contact with wounds 

 on the body, and yet the rare occurrence of the disease can be 

 explained by the fact that successful infection occurs only when 

 large masses of bacilli enter the lymph spaces of the connective 

 tissue which contain but little oxygen. On the other hand, where 

 the infectious material enters superficial wounds on the skin, 

 granulating ulcerations, or even directly into the blood stream, 

 the bacilli cannot propagate on account of the presence of 

 oxygen. Hence the infection occurs either through contused or 

 lacerated wounds or during parturition by means of contami- 

 nated hands or instruments. In other cases the infection may 

 also follow vaccination, castration, shearing, bleeding, intro- 

 duction of seatons, subcutaneous injections with unsterilized 

 medicines (eserine, morphine, creolin, arecoline), unclean 

 syringes, bites, penetration of straws into the canthus of the 

 eye, etc. The disease has also developed in association with 

 necrotic processes. 



Lembeken observed 50 out of 600 and Gilruth 300 out of 4,000 sheep dying 

 from malignant edema during or after shearing. 



Infection may also occur through injuries or necrotic ulcer- 

 ations on the mucous membrane, whereas the healthy mucous 



