49° . MICROBIOLOGY OF SPECIAL SIGNIFICANCE 



The last three classes comprise the microbial food poisonings, and 

 these are the kinds of food poisoning mth which we are at present more 

 particidarly concerned. 



Infections of Food-producing Animals Transmissible to Man 



Animals dead of infectious diseases or slaughtered in the last stages 

 of disease are not ordinarily used for food, nor is the milk of such 

 animals ordinarily considered wholesome. This custom is certainly 

 an ancient one, and is, doubtless founded upon observation of -un- 

 favorable results following the consumption of such food. Exact 

 knowledge of the nature of the diseases transmitted in this way is a 

 more modern development, and this more exact knowledge is now 

 being apphed to some extent through food-inspection regulations to 

 prevent the transmission of such diseases. 



Tuberculosis of cattle has been shown by Smith to be due to a germ 

 somewhat dififerent from that causing the ordinary human tuberculosis, 

 and this discovery has called into question the necessity of avoiding 

 the use of food products from tuberculous animals. After a con- 

 siderable amount of controversy it may now be regarded as definitely 

 established that the bovine tj^e of tubercle bacillus is capable of 

 infecting man, and that a very considerable proportion of cases of 

 tuberculosis in children are due to this type of organism, the infection 

 probably arising through the use of milk from tuberculous animals. 

 Anthrax, glanders, actinomycosis, and acute enteritis of animals are 

 also transmissible to man. . Food products from animals afflicted with 

 these diseases should not be used until they have been passed upon by 

 competent authority. Further information concerning them will be 

 found in the sections dealing with these particular diseases. 



The human disease known as septic sore throat may be due to in- 

 fection with streptococci present in cow's milk. Whether these virulent 

 streptococci are derived from an inflamed udder of the cow or from the 

 throats of persons who handle the milk is not fully ascertained, but 

 the inflamed udder is to be looked upon with suspicion. 



In this connection it may be mentioned that some of the animal 

 parasites, especially trichinae and various sorts of tapeworms, gain 

 access to the human body with the food. Thorough cooking usually 

 serves to kill these parasites, as well as the pathogenic bacteria, but 



