BACTERIOLOGY OF MEAT AND MEAT PRODUCTS 129 



III. Bacterial food infections and food poisoning. 



Attacks of food poisoning due to bacteria vary greatly in 

 seventy and in extent, ranging from mild attacks limited to a 

 few individuals to extensive outbreaks involving a large pro- 

 portion of the consumers of the infected food and causing 

 amongst those affected severe symptoms and some deaths. The 

 food eaten is generally meat in some form but not invariably so, 

 and there are many outbreaks on record following the consump- 

 tion of ice-cream, potatoes, milk, etc. The meat has frequently 

 been eaten in the form of pies, brawn, sausages, tinned foods, or 

 other made up meat food 1 . 



The bacteria concerned in these outbreaks may be con- 

 veniently classed into three groups : 



(1) Putrefactive and intestinal bacteria such as B. proteus, 

 B. coli. 



(2) B. botulinus. 



(3) Organisms of the Gaertner group. 



The respective parts played by these three groups in food 

 poisoning must be briefly considered. 



Putrefactive and intestinal bacilli. 



At one time most cases of food poisoning were ascribed to 

 the chemical activities of putrefactive and intestinal bacilli, 

 particularly one or other of the organisms described as Proteus 

 vnlgaris, Proteus mirabilis, etc. 



This conception was largely based upon a series of interesting 

 investigations upon the chemical products of putrefaction. It 

 was ascertained that when meat was allowed to putrefy certain 

 basic bodies (called ptomaines by Selmi), which closely resemble 

 the vegetable alkaloids, could be isolated, and that these bodies 

 were possessed of highly poisonous properties as shown by their 

 injection into laboratory animals. The symptoms produced 

 were in some ways similar to those met with in cases of food 



1 For a detailed consideration of the etiology, epidemiology and pathology of Food 

 Poisoning see "Report to the Local Government Board on Bacterial Food Poisoning 

 and Food Infections" by W. G. Savage, 1913. New Series, no. 77. 

 S. \7. 



