58 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



ANTHRAX 



Anthrax occurs in man in three forms. The most common is 

 cutaneous anthrax, or, as it is sometimes called, malignant pustule. 

 Pulmonary anthrax, or wool-sorter's disease, is much rarer, and 

 intestinal anthrax rarer still. The practitioner will find the greatest 

 assistance from a bacteriological examination in the cutaneous 

 form of the disease ; he may search for the specific bacillus in 

 the sputum in a supposed case of wool-sorter's disease, but he 

 must be careful in his interpretation of his result, as bacilli which 

 might be mistaken by an untrained observer, relying on the 

 morphological appearances alone, sometimes occur in the sputum. 

 The search for bacilli in the faeces in a supposed case of intestinal 

 anthrax must be relegated to an expert. 



The true nature of a case which is examined post mortem can 

 easily be determined bacteriological ly ; the cut surface of the 

 liver or spleen should be rubbed upon a clean slide, and the films 

 treated secundum artem. They will probably show the bacilli in 

 large numbers. Sections may also be cut and stained by Gram's 

 method (see p. 191). 



In the later stages of any infection with anthrax the bacilli 

 may be found in the blood. They may be apparent on examina- 

 tion of stained films, or may be demonstrated by cultural methods 

 similar to those used in the diagnosis of malignant pustule. 



The anthrax bacillus varies considerably in length, but is 

 always a large organism, and may be considerably longer than 

 the diameter of a red blood-corpuscle. It is much thicker than 

 the bacilli which have been dealt with hitherto, and it is invariably 

 straight. The ends of these bacilli are cut sharply at right angles 

 to the sides of the organism, and may be even somewhat concave ; 

 this is a most characteristic feature. The anthrax bacillus stains 

 by Gram's method (Plate I., Fig. 4). 



In cultures the appearances are somewhat different. Here the 

 bacilli are frequently arranged in long chains which have an 

 appearance which has been compared to that of a bamboo ; chains 

 occur in the blood or in the inflammatory exudate, but are usually 

 much shorter than those seen in cultures. But the most important 

 features in cultures of the anthrax bacillus is the development 

 of spores, which are oval, highly refractile bodies, and lie in or 

 near the centre of the bacilli, one in each. These spores are 



