SPORE-FORMING PATHOGENIC ORGANISMS 83 



Bacillus (Clostridium) Ckauvcei. 



Black-leg, quarter-evil, or symptomatic anthrax is un- 

 known in man, but in sheep and oxen a fatal termination 

 is to be apprehended one or two days after infection. 

 Localised swellings appear on the neck, shoulders, or 

 thighs, and the affected muscles become discoloured. 

 Puncture of infected muscle produces a frothy, sanguineous 

 fluid, which contains the organism. The organism is a 

 rod about 4 JLI long, and is actively motile. The large 

 spores give it club- and spindle-shaped appearances. It 

 is a strict anaerobe, and is usually Gram-negative. It 

 grows in agar and gelatin cultures with the production 

 of a foul gas. Gelatin is slowly liquefied. Kitt says the 

 odour is due, not to B. Chauvwi, but to contamination 

 with ' cadaver bacilli.' By drying an affected muscle at 

 35 C. and then heating to 85 or 90 C., attenuation in 

 virulence is effected, and the materials injected for the 

 production of immunity. 



Red Braxy in sheep is associated with an organism 

 similar to B. Chauvcei, which, however, differs in its action 

 on other animals. The bacilli are very numerous in the 

 intestine and in the reddish-brown blood-stained mucus 

 that collects in the last and true digestive stomach. 

 After death, decomposition is very rapid, and the crimson 

 colour of the fourth stomach is sometimes mistaken for 

 a symptom of irritant poisoning. Hamilton found that 

 during July and August the serum of healthy sheep did 

 not allow multiplication of braxy bacilli. Very satis- 

 factory immunity is obtained by dosing lambs by the 

 mouth when their blood is most refractory to the organism. 



Bacillus Botulinus. 



Morphology. A large bacillus (4 ft to 10 /LI long), with 

 rounded ends, and a tendency to form short chains. 

 It is an obligatory anaerobe, exhibits a slight motility, 

 and forms spores. The spores are often destroyed by a 

 temperature of 80 C. The position of the spores is 

 generally terminal, and the flagella number from four to 

 eight. The organism is Gram-positive. 



Cultural Characters. Cultures must be grown in the 

 dark. Milk is not curdled; glucose is fermented with 

 production of acid and gas; saccharose and lactose are 



