CHAPTER VI 



UDDER-STREPTOM YCOSIS ( STREPTOCOCCIC 

 MASTITIS) 



The infectious organism is one or more of the strep- 

 tococcic group of pathogenic type. 



Character. — The pathogenic streptococcus is a small 

 egg- or spherical-shaped organism which occm's regularly 

 as a chain of two or more individuals joined together. 

 It is easily stained with the common anilin dyes and also 

 with Gram's method. The cultures are light or thin on 

 the usual cultural media, especially surface growths. Gela- 

 tin and milk are unaltered. 



The last characteristic, the condition of the milk, 

 sharply differentiates the pathogenic streptococci from the 

 non-pathogenic lactic acid streptococcus, which is found in 

 milk, and which resembles the pathogenic streptococcus to 

 such a great extent culturally and morphologically. 



There are names for the different types of pathogenic 

 streptococci, as diplococcus pneumonia and streptococcus 

 pyogenes, both found in man, streptococcus equi and Schiitz 

 diplococcus, both in the horse, and also the streptococcus 

 mastitidis found in the cow.^ 



These groups of streptococci are differentiated princi- 

 pally through their various sources. Otherwise they show 

 very little morphological and biological difference. It is 

 clear that the place in which the organism was found, its 

 source, is no authentic and definite type characteristic, and 



* The galactococcus fulvus and galactococcus versicolor iso- 

 lated from mastitic milk by Guillebeau certainly belong to the 

 streptococcic group, while the galactococcus albus, which was only 

 once isolated by Guillebeau, perhaps belongs with the micrococcus 

 tetragenus (sarcina tetragena, Lehmann and Neumann). 

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