BACTERIAL FLORA OF INTRA-MAMMARY MILK 95 



Kolle, 80 to 15,000 per c.cm. 



33 per cent less than 300. 



50 per cent less than 500. 



4.7 per cent 700-800 

 Willem and Minne, 1 to 5 per c.cm. 

 Willem and Miele, to 37 and 4 to 218 per c.cm. 



Siebald, (1) Without protective measures. Under 10 to 



several thousands. 



(2) After soaping the udder. to 85 per c.cm. 



(3) After soaping the udder and disinfecting with 



alcohol and milking through sterile tubes, 

 to 12 per c.cm. 



All these numerous experiments prove conclusively that some 

 intra-mammary contamination of milk exists and it will be 

 advisable next to consider the nature of this. 



Like Ward ^ Freudenreich ^ found that udder contamination 

 in healthy cows was mostly caused by cocci, but Str. lacticus 

 (Heinemann) was only found in three cases out of a total of 

 fifteen. B. coH was never found. The organisms found by 

 Henderson ^ were streptococci, staphylococci and pseudo diph- 

 theriae and similar results were obtained by Bergey.^^ 



From these and other results it would appear that cocci, 

 some of a proteolytic nature, form the prevailing type found in 

 udders and that the lactic acid producing bacteria, both coli- 

 form and Str. lacticus, are usually absent. Some of the strep- 

 tococci and staphylococci found in milk produced under strictly 

 aseptic conditions are biochemically similar to those usually 

 associated with inflammatory processes but are commonly of 

 much lower virulence. 



Experiments on the viability of various organisms in the 

 environment of milk ducts has shown that they rapidly die, 

 many bacteria disappearing within a few days. Savage ^^ 

 inoculated the teats of goats with streptococci of both bovine 

 and human origin and found that the infecting organism 

 usually died in a few weeks, although in one case the strep- 

 tococci persisted for over seven months. The streptococci 

 from human sources were usually less viable. 



