344 PATHOGENIC MICROORGANISMS 



Toxic Products.^ — In spite of extensive researches by many inves- 

 tigators upon the nature of the poisons produced by streptococci, 

 our understanding of these substances is still very incomplete. The 

 grave systemic symptoms so often accompanying comparatively 

 slight streptococcus lesions argue strongly for the production by these 

 microorganisms of a powerful diffusible poison. Toxic filtrates of 

 streptococcus cultures have indeed been obtained by Roger/ Marmier,^ 

 Baginsky and Sommerfeld,' Marmorek/ and many others; but these 

 have in no case been comparable in potency to the soluble toxins of 

 diphtheria or of tetanus. When injected into young guinea-pigs in 

 sufficient quantity, these filtrates produce rapid collapse and death. 

 The inability to produce strong toxins is generally attributed to the 

 difficulty of obtaining very abundant growth of these bacteria upon 

 fluid media, development being self-limiting, either because of the ex- 

 haustion of specific nutritive material (Marmorek '), or, more probably, 

 because of the inhibitory effects of the products of growth, chiefly acid 

 formation. This last factor can be partially overcome by the use of the 

 glucose-calcium-carbonate broth mentioned above, in which acid neutral- 

 ization is constantly taking place. For toxin production, Baginsky and 

 Sommerfeld * advise a strongly alkaline reaction of the media; Mar- 

 morek ' has used human blood-serum-bouillon with success. The 

 toxins so produced are relatively thermostable. According to v. 

 Lingelsheim, heating to 60° or 70° C. destroys them in part only. 

 The endotoxins contained within the cell-bodies of streptococci them- 

 selves have been found to possess but slight toxic qualities. 



Apart from these substances, some streptococci produce a hemolysin 

 which has the power of bringing about destruction of red blood cor- 

 puscles. The observation of this phenomenon for streptococci was first 

 made by Marmorek * in 1895. According to this author, there is a 

 direct relationship between virulence and hemolytic power. Other 

 investigators, however, notably Schottmiiller,' believe the hemolytic 

 power to be a constant characteristic of certain strains unchangeable by 



1 Roger, Rev. de m6d., 1892. 



" Marmier, Ann. de I'inst. Pasteur, ix, 1895, p. 533. 



' Baginsky und Sommerfeld, Berl. klin. Woch., 1900. 



* Marmorek, Berl. klin. Woch., 1902. 



' Marmorek, Berl. klin. Woch., xiv, 1902. 



^ Loc. cit. 



' Marmorek, Ann. de I'inst. Pasteur, 1895. 



' Marmorek, Ann. de I'inst. Pasteur, 1895. 



' Schottmuller, Munch, med. Woch., 1903. 



