138 BOTULISM 



same organism. Later still, other small outbreaks have been studied 

 and the bacillus botulinus found in all. 



The Bacillus. This is a rod (from 4 to 6 microns long by 0.9 to 

 1.2 of a micron broad) with imperfectly rounded ends. It often 

 appears in chains formed of two or more rods, attached end to end. 

 It is slightly motile, carrying from four to eight flagellae. It forms 

 spores, which for the most part are terminal, rarely central. It takes 

 ordinary stains easily and is strictly anaerobic. In pure cultures it 

 will not grow in the presence of air, but in mixed cultures it may 

 do so, the other organisms consuming the oxygen. It develops gas, 

 especially in media containing grape-sugar or other carbohydrate. 

 It grows only feebly at the temperature of the animal body. Special 

 interest attaches to this bacillus because it is not a pathogenic, but 

 is a toxicogenic organism. When grown outside the body as in the 

 ham, it elaborates a poison or toxin and it is to this that its harmful 

 effects are due. It causes not an infection, but an intoxication. When 

 all the bacilli have been removed by filtration through porcelain, the 

 clear filtrate is just as poisonous as the original culture. Indeed, the 

 bacillus does not multiply in the animal body, or does so only to a 

 slight extent. Another very striking fact is that the soluble poison 

 affects many animals when taken by the mouth. Most toxins and 

 venoms are harmless when introduced into the alimentary canal, but 

 this is not. One one-thousandth of a cubic centimeter, and even a 

 smaller dose, of germ-free filtrate kills a rabbit. An effective anti- 

 toxin has been prepared and used. 



It is to be remembered that it is not this organism which causes 

 most instances of food poisoning, in which nausea, vomiting, and 

 purging are prominent symptoms. Bacillus botulinus apparently is 

 not widely distributed. So far it has been found only once except in 

 food, and that was in the feces of hogs. As has been stated, it grows 

 only in the absence of air and it has been found in canned foods. In 

 such, it produces gas which bulges the ends of the can. In brine of 

 more than 10 per cent, strength it will not grow. It is of especial 

 interest because it is essentially a saprophytic organism, producing in 

 food, in the absence of air, a most potent poison which affects man 

 when taken into the stomach. 



