178 BACTERIOLOGICAL METHODS 



large anaerobic sporogenous saprophyte especially common in 

 sausages and sausage meats, particularly in liver sausages, blood 

 sausages, jelly sausages, in hams, in liver pate, canned meats, 

 etc., etc. The bacillus, inclusive of the spores and the highly 

 virulent toxins which it forms, are destroyed by boiling and 

 thorough cooking. The digestive ferments do not destroy the 

 toxin. The usual smoking of hams and sausages does not de- 

 stroy the toxin or the' bacillus. The bacillus is killed by strong 

 brines, but this does not also destroy the toxin. The oval spores 

 are quite readily killed by heat and chemicals. Heating to 80 

 C. for i hr. kills them. Ichthyotoxism (fish poisoning) and 

 mytilotoxism (shellfish poisoning) are closely akin to botulism 

 and are in all probability caused by the same bacillus or perhaps 

 a varietal form of B. botulinus. The occurrence of the Bacillus 

 botulinus is, however, not limited to pork and sausage meats. 

 Well-authenticated cases are on record of the occurrence of this 

 bacillus in canned vegetables and in domestically prepared string 

 beans served without previous heating. There is no doubt 

 that the heat employed in the canning process destroys the toxin 

 formed, but the temperature may not always be high enough to 

 kill all of the bacilli and their spores even though the spores are 

 not very resistant to heat (80 C.). Bacillus botulinus does not 

 multiply in the living organism. It grows readily in slightly 

 alkaline media at a temperature of 18 to 25 C. At higher tem- 

 peratures (35 to 37 C.) it grows only sparingly and without 

 the formation of toxin. Cultures give out an odor of butyric 

 acid. 



In pickled, canned and otherwise prepared and preserved 

 meats, and mixtures of meat and vegetables (chop suey, pork and 

 beans, etc.), the processes of bacterial development are greatly 

 modified. The use of deodorants, of preservatives and color- 

 ing agents mask or obscure many of the decomposition changes 

 in meats. Very frequently the only cause for suspicion is an 

 unusually heightened color or a lack of the normal meat flavor. 



