524 A MANUAL OF BACTERIOLOGY 



and producing acid but no gas in glucose media. It clots milk 

 with an intense acid reaction. 



Bacillus botulinus [Clostridium botulinum] 



Van Ermengem isolated this anaerobic bacillus in cases of 

 poisoning associated with the consumption of sausages. It has 

 also been met with in forage poisoning ^mules) and in certain 

 vegetable products (see Chapter XXI.). The symptoms are 

 caused by the absorption of toxin, which has a special effect on the 

 nerve centres. 



The organism is a large Gram -positive sporing anaerobic 

 slightly motile bacillus, often occurring in pairs or in short chains. 

 The spores are small and oval, and generally sub-terminal. The 

 organism is difficult to cultivate as the slightest acidity inhibits 

 growth. The best results are obtained in media containing fresh 

 tissue or glucose : strict anaerobiosis is necessary. In glucose 

 gelatin it forms a whitish streak in the line of the stab, with lateral 

 outgrowths, liquefaction of the medium, and gas-formation. The 

 cultures have a rancid odour, due to butyric acid production. 

 Serum is not liquefied. Colonies in glucose-agar shakes are 

 lenticular or reniform. CHycerol, glucose, maltose, lactose and 

 starch are alone fermented. Milk is unchanged. The optimum 

 growth is from 20-30 C. 



The B. botulinus in broth cultures forms a potent extra-cellular 

 toxin, which is toxic both by injection and by ingestion. The 

 toxin is also produced in the infected food. With the toxin an 

 antitoxin can be prepared. The organism is somewhat pathogenic 

 for guinea-pigs. Kabbits, guinea-pigs, mice, cats and monkeys 

 are very susceptible to the toxin. B. botulinus has never been 

 recovered from wounds. 



Black Quarter 



Synonyms. Black Leg, Quarter Evil, Symptomatic Anthrax, 

 Eauschbrand, Charbon symptomatique. 



Black quarter is a disease affecting sheep and oxen, and is un- 

 known in man. The names black quarter, black leg, and quarter 

 evil are derived from the dark discoloration of the muscles of the 

 leg and flanks or quarters of the affected animals. When the 

 muscles are cut into, a thin sanguineous fluid exudes, and in this 



