290 Microbes and You 



In the first place, anaerobic conditions are lacking, and Clostridium 

 botulinwn grows only in the absence of free atmospheric oxygen. 

 Secondly, the low temperature at which the food is stored allows 

 little microbial activity to occur, and the toxin must be pre- 

 formed in the food before clinical symptoms will occur in persons 

 who consume the food. Frozen foods may cause poisoning, how- 

 ever, if large numbers of specific organisms were present in the 

 food which was held too long at warm temperatures prior to 

 freezing, or if the thawed product becomes contaminated and is 

 allowed to remain too long at warm temperatures before being 

 consumed. Freezing generally does not destroy bacteria; it merely 

 preserves them. 



Because true exotoxins are produced by the botulinum organ- 

 isms, antitoxins are available and are indicated for use if the 

 disease can be diagnosed early enough. The more time that 

 elapses before the administration of antitoxin, however, the less 

 promising results can be expected. Five specific toxins are 

 produced by different strains of Clostridium botulinum, and five 

 specific antitoxins are available to counteract these poisons. Since 

 antitoxins are specific only for the particular toxin against which 

 they are produced, it is necessary to administer a mixture of 

 antitoxins, called a bivalent or polyvalent antitoxin, to meet any 

 eventuality. Time cannot be taken to determine the specific type 

 of poison involved in a given case, or the injection of antitoxin 

 may be delayed too long to do the patient any good. 



STREPTOCOCCUS AND OTHER BACTERIAL POISONINGS 



While streptococci are not found as com.monly in food-borne 

 outbreaks as staphylococci or Salmonella species, they can cause 

 severe illness. The alpha (green) streptococci are usually in- 

 volved if this organism is the cause of the poisoning. Since these 

 bacteria are normal inhabitants of our nasopharynx, persons who 

 cough and sneeze over food may spray enough streptococci to 

 serve as an inoculum which can grow in food under proper 

 temperature conditions. Following an incubation period of from 



