THE STREPTOCOCCUS GROUP 273 



ammonia, methylamine, propyl pyridin, succinic acid, butyric acid 

 and other volatile acids among the anaerobic decomposition products 

 of fibrin by this organism, but no aromatic derivatives. 



Toxin. A soluble toxin has not been demonstrated in cultures of 

 streptococci, although substances have been isolated by Marmorek 1 

 and others which will kill guinea-pigs. These substances do not 

 exhibit sufficient potency to warrant the assumption that they are 

 important factors in the production of the grave symptoms charac- 

 teristic of severe streptococcus infections. Attempts to demonstrate 

 endotoxin have also been unsuccessful; the bodies of the organisms 

 are but slightly toxic to experimental animals. The manifestations 

 of toxemia in streptococcal infections, however, are too striking to 



FIG. 34. Streptococcus in pus. X 800. 



be reconciled with the negative results of these investigations; the 

 nature of the mechanism of streptococcus infection remains to be 

 elucidated. 



Hemolysin Streptocolysin. Bordet 2 and Besredka 3 have shown 

 that filtered broth cultures of streptococci will dissolve red blood 

 corpuscles, liberating hemoglobin, and that this hemolytic substance 

 streptocolysin is active both in mw and in vitro. Frequently the 

 blood of rabbits injected with streptocolysin was found to be u laked" 

 just before death. Besredka's observations would indicate that the 

 substance is rather firmly bound to the organisms and does not appear 

 in the medium to any considerable degree. M'Leod, 4 M'Leod and 



1 Berl. klin. Wchnschr., 1902, xiv, 253. 



2 Ann. Inst. Past., 1897, xi, 177. 

 a Ibid., 1901, xv, 880. 



4 Jour. Path, and Bact., 1912, xvi, 321. 



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