THE SPORE-BEARING RODS 365 



ticularly in meat foods and sausages. In the United States 

 practically all of the cases reported have been from the 

 eating of imperfectly preserved canned foods. A consider- 

 able variety of these have been found to be at fault. Cases 

 of poisoning from canned asparagus, canned beans and ripe 

 olives have been reported. Most of the cases have been 

 from the Pacific coast. 



Morphology. The Clostridium botulinum is a relatively 

 large bacillus, usually single, occasionally in pairs or chains. 

 It is '.9-1. 2/z X 4-6/4. It is actively motile by means of 

 from 4 to 8 peritichous flagella. Oval or elliptical spores 

 are produced, one near the end of each cell. The organism 

 stains readily and is Gram-positive. 



Culture. Care must be taken to exclude oxygen in the 

 growth of Clostridium botulinum. It grows fairly readily 

 in ordinary cultural media. 



Physiology. The organism is an obligate anaerobe. 

 Some strains grow best at room temperatures, others at 

 body temperature. Apparently there are several distinct 

 varieties of this organism which show minor differences in 

 physiological reactions Gas is generally produced from 

 dextrose but not from sucrose or lactose. 



Pathogenesis. When growing under favorable condi- 

 tions, the Clostridium botulinum produces a highly potent 

 toxin. Usually this is accompanied by the formation of 

 malodorous substances, particularly butyric acid. Usually 

 food in which this organism has been growing can be 

 detected by having an "off" odor. Such foods must be 

 carefully avoided as even a small portion of such food, 

 sometimes not more than a mere taste, has proved sufficient 

 to be fatal. 



The toxin produced by growing the organism in culture 

 media is quickly fatal to laboratory animals when fed or 

 injected. It is also fatal frequently to man. In man the 



