Streptococcus Pyogenes 357 



mained unchanged upon artificial culture -media for eight 

 years without any particular precautions having been taken 

 to maintain the virulence. 



Dried streptococci are said by Frosch and Kolle * to retain 

 their virulence longer than those growing on culture-media. 



Marmorek f and Lubenau J found that cultures of the strep- 

 tococcus when grown in bouillon containing glucose, produced 

 a hemolytic substance streptokolysin not seemingly pres- 

 ent in cultures grown in ordinary bouillon. Besredka 

 found that streptokolysin was produced only by highly viru- 

 lent cultures of the streptococcus and not by saprophytic 

 organisms that have been for some time under cultivation in 

 the laboratory. 



Levin |1 investigated the subject thoroughly and found 

 that different strains of streptococci produced strepto- 

 kolysin in varying quantities, that its production is entirely 

 independent of virulence, that it is destroyed by heat 

 (37 C. in some days; 55 C. in one-half hour); that acidity 

 of the nutrient media hinders its formation, and that it is 

 intimately associated with the bodies of the streptococci 

 by which it is produced, so that in the sediment obtained by 

 filtration or by centrifugation there is nearly one thousand 

 times as much as in the filtered fluid culture. The strepto- 

 kolysin is not destroyed by the death of the bacteria. An- 

 tistreptokolysin is present in antistreptococcus serum. 



Toxic Products. The toxic products of the strepto- 

 coccus are not well known. Cultures from different sources 

 vary greatly in the effects produced by hypodermic or intra- 

 venous injection after filtration through porcelain. Killed 

 cultures produce a much more marked effect than filtered 

 ones, so that the important product must be an endotoxin. 



Simon** found that the toxic quality of the bodies of 

 streptococci of different stocks had nothing to do with their 

 virulence. Simon ft also found that the toxic products of 

 the streptococcus were diverse and peculiar. The bodies 

 of the cocci contained an intracellular toxin the activity of 



* Flugge's "Die Mikroorganismen." 



t "Annales de 1'Inst. Pasteur," 1895, 593. 



t "Centralbl. f. Bakt.," etc., 1901, Bd. xxx, Nos. 9 and 10. 



"Ann. de 1'Inst. Pasteur," 1901, p. 880. 



|| "Nord. Med. Ark," 1903, n, No. 15, p. 20. 

 ** "Centralbl. f. Bakt.," xxxv, No. 3, p. 308, Dec. 18, 1903. 

 tt Ibid., xxxv, No. 4, p. 350, Jan. 16, 1904. 



