THE PRESENCE IN MILK OF CERTAIN ORGANISMS 247 



of milk obtained fresh from the farm and examined within three 

 hours, streptococci were found in all. 



It is not necessary to adduce further evidence to show that 

 streptococci are widely distributed in the milk supply of most 

 countries. 



The sources of the organism have been studied by numerous 

 observers, and it has been shown that streptococci can be obtained 

 from the udder, mouth, faeces, and milk of the cow, 1 and that they 

 are found on the human body * and in numerous other localities. 

 Roger found that most of the varieties of streptococci present in 

 the milk were derived from the udder of the cow. 



It has long been known that there are many different varieties 

 of streptococci, and numerous efforts have been made to classify 

 them as pathogenic or non-pathogenic, according to the appearance 

 and cultural properties of the different strains. 



Streptococci are responsible for a number of diseases or affections 

 in man, and for a large proportion of the cases of mastitis, or 

 inflammation of the udder, in cows. It is clearly important to 

 determine whether the streptococci found so generally in milk, 

 are liable to produce disease in those who consume the milk. 



With this object prolonged investigations have been carried 

 out upon the pathogenicity or otherwise of the strain of streptococci 

 found in milk, and also those obtained from the sufferers in milk- 

 borne epidemics of sore throat. 



The classification of streptococci found in milk in relation 

 to their cultural properties cannot be regarded as having been very 

 successful. 



Savage endeavoured to classify them according to the lines 

 suggested by Gordon, but without success. 



Miiller, who investigated the streptococci found by Kaiser in 

 his investigations in Gratz, believed that there was a close relation- 

 ship between the streptococci found in milk and those which are 

 pathogenic to animals. Of the strains examined, three appeared 

 to be identical with the pathogenic varieties, and produced 

 haemolysis of red corpuscles when cultured. 



Ruediger considers it possible to differentiate the Streptococcus 

 commonly found in milk from the Streptococcus pyogenes, by 

 means of blood agar plates. He believes that the Streptococcus 

 lacticus has no sanitary significance. The Streptococcus pyogenes 

 does not occur commonly in milk, but when found it denotes 

 an inflammatory condition of the cow's udder. Thirty-five strains 

 were examined. 



Heinemann (i), however, considers that the Bacillus acidi lactici 

 is in reality the Streptococcus lacticus, and that it agrees in cultural 

 and coagulative properties with the pathogenic streptococci obtained 

 from sewage and faeces. The Streptococcus lacticus was found by 



1 Cp. Roger. Cp. Zangmeister. 



