410 GLANDERS, ANTHRAX, PYOCYANEUS 
small ainoiuits of leucin and tyrosin in a serum culture of B. anthracis. 
Xo acid or gas is produced in any sugar media. The albumoses and 
peptone caused a febrile reaction in animals, and the alkaloidal sub- 
stance (anthrax-alkaloid) caused edema and congestion. These results 
have never been repeated. ^ 
Enzymes.— Bacillus anthracis produces a proteolytic enzyme which 
liquefies gelatin, blood serum and casein. No other enzymes are 
known. 
T'o.ri?? 5.— Soluble toxins have not been demonstrated in cultures 
of anthrax bacilli, and the nature of the endotoxin is unknown— the 
cellular substance of the organism is not as toxic as that of many other 
pathogenic bacteria, and the nature of the pathogenic action of the 
bacillus is not clearly determined. 
Pathogenesis. — .4 nima^.— Anthrax is a disease of cattle, sheep- and 
horses. Swine are less susceptible. Guinea-pigs, rabbits and white 
mice are very susceptible to inoculation. Rats and dogs succumb to 
large doses. Birds and cold-blooded animals are naturally immune, 
although, as Pasteur showed, the immimity may be overcome by 
reducing the body temperature of birds and by raising the body tem- 
perature of cold-iilooded animals. 
The artificially-induced disease in small laboratory animals is 
usually a rapidly fatal septicemia; the organisms swarm in the blood- 
vessels and appear upon section to almost occlude the capillaries. 
The spleen is greatly enlarged and there is congestion of the other 
glandular organs. Cattle and sheep readily succumb to infection 
with pure cultures of the organism. The natural infection in cattle 
and sheep appears to be chiefly through the intestinal tract. In horses 
infection may take place through the skin as well. Less commonly 
cutaneous infection may occur through wounds in cattle and sheep. 
A localized severe inflammation results which may heal spontaneously 
or lead to a generalized infection. It is stated that flies, particularly 
the horse flies (Tabanidese) may transmit the virus to animals. The 
disease may also be transmitted experimentally by the inhalation of 
spores; this method of infection is probably not common in animals. 
II union. —Anthrax bacilli or their spores may cause disease in man 
either by gaining entrance to the body through abrasions of the skin, 
by inhalation, or by ingestion. Inoculation through the skin may 
give rise to malignant pustule, characterized by a small papule at the 
site of infection, wdiich soon becomes vesicular. The process may 
stop spontaneously with the formation of a scab and the gradual 
drying up of the vesicle, or the inflammation may spread, producing 
a wide area of induration in which vesicles appear, often in consider- 
able numbers. The involved area becomes edematous, and the 
regional glands become enlarged. Death may ensue within five to 
1 It is probable that these substances were produced from the serum by the action of 
the organism; they cannot be regarded as specific toxic products. 
■^ Algerian sheep are said to be more resistant to infection than ordinary sheep. 
