844 BACILLUS 



In the dry state the spores may remain alive for 12 years or more (Pasteur 

 1881a). According to Murray (1931), a saline suspension containing 1,000,000 

 spores per ml. is sterilized by moist heat at 90° C. in 15 to 45 minutes, at 95° C. 

 in 10 to 25 minutes, and at 100° C. in 5 to 10 minutes. 



The antigenic structure of the anthrax bacillus has received considerable atten- 

 tion. As early as 1921 Kramar obtained evidence that the capsule contained a 

 glycoprotein probably belonging to the class of pseudomucins. A soluble specific 

 carbohydrate, incapable of giving rise to antibodies on injection into animals, but 

 reacting to a high titre with anti-anthrax serum, was extracted from anthrax bacilli 

 by Combiesco, Soru, and Stamatesco (1929). A similar substance was prepared by 

 Schockaert (1929). It is, however, mainly to the work of Tomcsik (1930), Tomcsik 

 and Szongott (1932, 1933), Tomcsik and Bodon (1934, 1935), Bodon and Tomcsik 

 (1934), Sordelli and Deulofeu (1930, 1933) and Sordelli, Deulofeu, and Ferrari (1932) 

 that our knowledge of the antigenic structure of this organism is due. There appear 

 to be two main antigens ; one a protein-like substance present in the capsule, the 

 other a polysaccharide substance present in the body of the organism. Specific 

 precipitins for both the protein-like and polysaccharide constituents are found in 

 serum prepared by the injection of animals with capsulated bacilli, and each can 

 be differentially absorbed in the usual way. In animals infected with anthrax 

 both antigens can be demonstrated in the tissues by the use of precipitating sera. 

 Later observations by Ivanovics and Erdos (1937), and Ivanovics and Bruckner 

 (1937a, h, 1938), have shown that the capsular substance contains a group-specific 

 hapten common to B. anthracis and certain other members of the Bacillus group. 

 It appears to consist of a polypeptide of high molecular weight containing d{ — )- 

 glutamic acid. It reacts in high titre with a precipitating- serum prepared by the 

 inoculation of rabbits with heat-killed capsulated anthrax bacilli, but cannot by 

 itself stimulate the formation of antibodies (Tomcsik and Ivanovics 1938). The 

 somatic polysaccharide is said by Ivanovics (1940) to consist of glucosamine and 

 galactose with acetic acid attached to the molecule. 



The anthrax bacillus is naturally pathogenic mainly to the herbivora and to 

 man, but occasionally it attacks other animals. Experimentally it proves fatal to 

 the mouse, guinea-pig, and rabbit, less often to the rat. The larger the dose, 

 the shorter is the time to death. Subcutaneous injection of 1 loopful of an 18 hours' 

 agar culture kills mice, guinea-pigs, and rabbits in about 12 to 30 hours ; a smaller 

 dose, 1/100 of a loopful, kills them in 30 to 40 hours ; a still smaller dose, 1/2,000,000 

 of a loopful, kills mice in 96 hours, guinea-^^igs in 56 hours, and rabbits in 104 hours 

 (Sobernheim 1897). Other members of this group never kill in such small doses. 



Post mortem, there is a gelatinous hsemorrhagic local oedema ; the viscera are 

 congested, the blood is dark red and coagulates less firmly than usual ; the spleen 

 is enlarged, dark red, and very friable. Microscopically, the bacilli are found in 

 large numbers in the local lesion, in the blood, and in the thoracic and abdominal 

 viscera ; they are confined almost entirely to the interior of the capillaries, where 

 their numbers may be so great as to cause obstruction to the blood flow ; the 

 tissues themselves are rarely penetrated. Though the disease terminates in a 

 septicaemia, it is not till 4 or 5 hours before death, as a rule, that the bacilli 

 actually gain access to the blood stream. 



Infection may also be successfully achieved by cutaneous, intracutaneous, 

 intramuscular, intraperitoneal or intravenous injection, or by feeding. The most 

 certain route is the intramuscular, the least certain the oral (Sobernheim and 



