92 



Effect of Internal Influences. 



group of pathogenic streptococci. Of the pyogenic strains of man, 

 according to Andrewes, the Streptococcus pyo genes and the Strep- 

 tococcus mitis produce acidity without coagulation. Sven Wall 

 proved these characteristics from the mastitis strains isolated by 

 him. According to Adametz, the mastitis cocci sometimes coagulate 

 very intensely, the same as is the case with the streptococci of 

 enteritis of sucklings (Petruschky). The fermentation in various 

 sugars using Gordon's bouillon mixtures, varies greatly with the 

 different pathogenic streptococci and milk streptococci, so that the 

 possibility of differentiation by this means is quite impossible, 

 which is likewise the case by testing their virulence on small test 



animals. Pathogenic 

 strains may at times show 

 great variations of viru- 

 lence, while according to 

 Heinemann strains of the 

 Streptococcus lacticus 

 may become virulent by 

 passage through rabbits, 

 until they will produce 

 changes in rabbits which 

 correspond in their ap- 

 pearance, extension and 

 character, to those caused 

 by pyogenic strains re- 

 covered from man. 

 Through their action on 

 animal bile, or on sodium 

 taurocholate, Mandel- 

 baum differentiates the 

 Streptococcus mucosus 

 and Pneumococcus from 

 Streptococcus pyogenes 

 and other streptococci 

 (Neufeld, v. Levy). The 

 author used the mastitis 

 strains he had on hand 

 on cattle, hog, horse and 

 chicken bile, but failed to observe either a clearing of the culture 

 media or an influence upon the form and appearance as shown by 

 the microscope. 



The establishment of the "virulence number" through phag- 

 ocytic experiments also fails to yield the desired result. 



In short up to the present time the absolute separation of 

 culture strains of varied origin, the differentiation of saprophytic 

 streptoccoci from mastitis streptococci, and these from pathogenic 

 streptococci of man has not been successfully accomplished. We 

 have, however, in certain morphologic indications, for instance 



Sediment of milk from an udder with acute inflammation. 

 Short forms of streptococci. 1 X 1000. 



