214 VETERINARY BACTERIOLOGY 



frequent transplantations being necessary to maintain it. It is 

 easily destroyed by disinfectants. 



Pathogenesis. Ostertag succeeded in producing abortion in a 

 pregnant mare by an intravenous injection. The organism is 

 not pathogenic to the common laboratory animals. Like the 

 preceding, it seems to be a case of specialized parasitism. Not 

 enough critical work has been done upon the disease to satis- 

 factorily establish the causal relationships of this organism. 



Immunity. No work is recorded relative to immunity to this 

 disease. Transmission is probably through coitus. 



Other Streptococci of Uncertain Significance 



Streptococcus mastitidis sporadicae. (Str. agalactice conta- 

 giosce, Str. der infektiosen Induration des Euters). 



Organisms of mammitis or mastitis in cattle have been found 

 in all parts of the world, frequently associated with the disease in 

 epidemic form. This organism was originally reported as gram- 

 negative, but the Str. mastitidis, gram-positive, is reported by the 

 local government board in England as the commoner type. There 

 are no good differential characters other than pathogenesis to 

 separate this latter form from Str. pyogenes and Str. lacticus. 

 On account of the general occurrence of this latter species in milk, 

 direct microscopic examination of the milk is often insufficient 

 for the purpose of determining the condition of the udder, i. e., 

 whether or not it is infected with garget. 



Streptococcus Sp. Epizootic pleuropneumonia in equines. 

 Stable pneumonia. 



A number of investigators have demonstrated a Streptococcus 

 present in the lesions of certain pneumonias in the horse. The 

 organisms isolated by different investigators have not always the 

 same cultural, morphologic, and physiologic characteristics. By 

 some the organism is regarded as identical with Str. equi, by 

 others as a specific type, and by still others it is believed that 

 the specific organism is still unknown, and the Streptococci de- 

 scribed are but secondary invaders. An organism resembling the 

 human pneumococcus, if not identical with it, has been isolated 

 from some cases of equine pneumonia, and will be considered in 

 connection with that organism. 



