12 MASS. EXPERIMENT STATION BULLETIN 426 



Type B: Capable of producing a toxin of high potency. According to some 

 authors it is associated with manured soils and soils cultivated for a 

 long time. Soils of Mississippi Valley, Great Lakes region, and Atlan- 

 tic Coast States are characterized by a predominence of Type B. 

 Associated with many outbreaks from home-canned foods. 



Type C: Reported to be cause of so-called "duck disease" and fowl "limber- 

 neck." Has not been associated with botulism outbreaks affecting 

 humans. 



Type D: A relatively rare type. It is believed that the susceptibility of man to 

 its toxin is low. 



Type E: Widely distributed but overlooked in the past. Isolated from Nova 

 Scotia smoked salmon and German canned sprats. Cause of fatal 

 cases of botulism in New York (Damon, 1928). Isolated from stur- 

 geon and seal meat in Europe. It has not been associated with home- 

 canned foods in the United States. 



In 1922, Meyer, Dubovsky, Coleman and Schoenholz reported the results of a 

 comprehensive surve>' on the distribution of the spores of CI. bottdinum in the 

 United States. In this investigation 2,162 samples of soil and soil products 

 were obtained from forty-seven states — from 1 to 624 samples from every state 

 of the Union with the exception of Virginia. Approximately 26 percent of the 

 specimens contained botulinum spores. A detailed study of the specimens 

 according to their source (soil type) emphasized the predominance of CI. botu- 

 linum in virgin and pasture soil. Earth contaminated with manure or animal 

 excreta rareh- carried the spores of this organism. On a basis of these data it 

 was suggested that cultivation and cropping of the soil reduces or dilutes the 

 number of spores to such a degree that the methods employed for detection failed 

 to demonstrate their presence. The authors concluded that, while there is no 

 doubt that every soil product may sometimes carry the spores of CI. botulinum 

 it is significant that string beans and leaves furnished the highest percentage of 

 toxic and identified cultures. In this connection reference might be made to 

 Table 2 which shows that string beans have been the most important cause of 

 botulism outbreaks from home-canned foods. 



It is also important to note that plant material undergoing decay and fermen- 

 tation supplied a high percentage of toxic cultures and isolations of CI. botulinum. 

 The authors point out that this organism, being a spore-former, rarely meets in 

 nature the conditions suitable for its growth. In soil, conditions favorable to 

 growth probably occur when decaying vegetation furnishes the necessary food 

 material. It is quite possible that the most heat-resistant spores do not occur 

 on fresh and sound vegetables and fruits, but only on produce which is partly 

 decayed or on that which has spoiled portions. With this in mind the recom- 

 mendation that only fresh, sound vegetables be used in home canning assumes 

 increased importance. On a basis of the survey- discussed above the authors drew 

 the following conclusions: 



1. CI. botulinum is a common soil anaerobe of the Western States of 

 the Cordilleran system. It is less frequently encountered in the Atlantic 

 States and is relatively rare in the Middle States, the Great Plains and the 

 Mississippi Valley. 



