20 Anthrax. 



is certain proof of anthrax, particularly when by staining the 

 presence of a capsule can be demonstrated. If, however, a 

 longer time has elapsed after death, especially in summer time, 

 other bacilli, first in importance bacilli of malignant edema, 

 may have migrated from the intestines into the blood, and 

 these in many instances can only be differentiated from anthrax 

 bacilli by cultural methods and animal inoculations. 



Bacteriological diagnosis. Relative .to distinguishing anthrax 

 bacilli from other bacteria more or less closely resembling them the 

 following is to be noted : 



1. Anthrax bacilli are present in the blood of fresh carcasses; 

 they are thick, rounded at the ends or squarely cut. They usually have 

 a distinctly recognizable capsule and form chains of 2 to 4, rarely 

 more, segments, in which the individual segments are separated from 

 one another by light cross lines; they are aerobic and never produce 

 spores inside the animal tissues and body fluids. Subcutaneous or 

 intravenous injections kill mice, guinea pigs and rabbits, in which 

 after death the blood usually contains the bacilli in great numbers. 



2. The bacilli of malignant edema are more slender, motile, rounded 

 at the ends, and besides, the edematous swelling, fluid of the abdominal 

 cavity and blood of- the portal vein contain curved thread-like forms 

 of various lengths, some homogenous, others beaded. In older car- 

 casses many of the bacilli contain in the center one oval spore each; 

 they are strictly anferobic, liquefy gelatin, and form gases even in 

 coagulated blood serum. Intravenous inoculations are harmless.; sub- 

 cutaneous inoculations into test animals produce a rapidly extending 

 edematous inflammation with gas formation. 



3. Blackleg bacilli are present only in the serous fluid of the 

 crepitating swelling in a fresh carcass; they are comparatively short 

 and thick, motile, never grow in form of threads, and produce in the 

 animal body shortly after death, oval spores located either at the end 

 or in the center of the bacillus. They may be grown anaerobieally but 

 also aerobically ; liquefy gelatin slightly ; and in coagulated blood serum 

 they do not produce gas. Intravenous inoculations are harmless; sub- 

 cutaneous or intramuscular inoculations kill the guinea pig and mouse, 

 but rabbits only as an exception. 



In the examination of material which is no longer fresh, various 

 putrefactive bacilli (Bac. subtilis, Bac. termo) come into consideration, 

 particularly those resembling saprophytes, the Bac. pseudoanthraeis 

 described by Burri & Baas, as well as the Bac. anthracoides found by 

 Hueppe & "Wood. They are found frequently in blood or parts of 

 organs that have been stored, and they have some characteristics in 

 common with the anthrax bacillus, but may be distinguished by the 

 absence of other characteristics of the true anthrax bacillus (Hoppe). 

 Further, they coagulate milk after a short time and do not form cap- 

 sules in inactivated horse blood serum. 



The anthrax bacillus may he demonstrated in most instances in sufficiently 

 fresh material by a microscopical examination for which the ■various capsule stain- 

 ing methods are especially adapted (according to Johne, staining with heated 2% 

 gentian violet solution followed by a quick discoloration with 2% acetic acid; 

 according to Olt with 3% safranin solution also with heating; according to Baebiger 

 staining of the air-dried smears with formol-gentian violet (100-150:10-15); 

 further, Gram's stain with subsequent eosin treatment). The material for exam- 

 ination should be taken from the blood or spleen of very fresh carcasses; later 



