CHAPTER XXXV. 

 . BACILLUS ANTHRACIS. 



Introduction. 



Section I. The experimental disease, p. 518. 



1. Susceptible and immune animals, p. 518. 2. Methods of inoculation, p. 519. 

 3. Symptoms and lesions in experimental animals, p. 519. 

 Section II. Morphology, p. 520. 



1. Microscopical appearance and staining reactions, p. 520. 2. Cultural charac- 

 teristics, p. 524. 

 Section III. Biological properties, p. 525. 



1. Viability and resistance, p. 525. 2. Virulence, Attenuation, Pasteur's vac- 

 cination, p. 527. 3. Toxin, p. 529. Vaccination with toxin, p. 530. 4. Serum 

 therapy, p. 530. 5. Agglutination, p. 533. 

 Section IV. Detection, isolation and identification of the anthrax bacillus, p. 533. 



Distribution of the bacillus, p. 533. Methods of examination, p. 534. 

 Examination of carcases dead of anthrax, p. 534. Isolation of the bacillus from 

 soil, p. 535. 



THE anthrax bacillus is the cause of anthrax in man and the lower animals. 



In man three forms of the disease are commonly recognized viz. malignant pustule, 

 pulmonary anthrax or woolsorter's disease, and intestinal anthrax. These three 

 clinical types correspond to the three channels of infection. The skin infection 

 (malignant pustule) follows contamination of an abraded surface when handling 

 the hides or flesh of animals dead of the disease. [In England malignant pustule 

 is seen chiefly among the hide porters at the various ports, and in the tanneries 

 of South London. ] Infection of the respiratory passages results from the inhala- 

 tion of dust containing the spores of the bacillus ; [it is the characteristic infection 

 in the wool- combing sheds of Yorkshire] and is hence sometimes known as the 

 Bradford disease. Intestinal anthrax is very uncommon ; when it occurs it is due 

 to the consumption of meat from anthrax-infected animals. 



In the lower animals the disease is variously designated : the commonest descrip- 

 tion being " splenic fever " or " splenic apoplexy " of sheep and cattle. Anthrax 

 in cattle and pigs in Brazil is known as garotilho. 



Infection of domestic animals takes place, as a rule, via the alimentary canal by 

 means of food contaminated with the spores of the bacillus. When anthrax-infected 

 carcases are buried the bacilli which are very numerous in the blood form spores. 

 These are brought to the surface in worm casts and being washed over the ground by 

 rain are subsequently taken up by animals grazing over the infected area, and 

 should the epithelial lining of the alimentary canal be abraded by thorns, splinters 

 of wood or other similar substance present in the food-stuff, the spores find a point 

 of entry into the tissues and multiplying under the favourable conditions of their 

 environment give rise to the disease (Pasteur). In Brazil, the carcases of anthrax-, 

 infected animals are devoured by vultures, and the latter disseminating the spores 

 in their excreta are, according to March oux and Salimbeni, the chief agents in the 

 spread of garotilho. 



