286 STREPTOCOCCUS-PNEUMOCOCCUS GROUP 



Enzymes have not been demonstrated in cultures of the pneumo- 

 coccus. 



Toxins. Soluble toxins have not been detected in cultures of 

 pneumococci, although the filtrates obtained by Klemperer, 1 Wash- 

 bourn, 2 and Isaeff 3 were toxic for small laboratory animals. The 

 toxicity observed in these preparations was probably due to the 

 liberation of endotoxins as the result of autolysis of pneumococci in 

 the medium. Macfadyen 4 has obtained toxic substances from two- 

 to three-day agar cultures of virulent pneumococci, which were 

 ground finely after freezing with liquid air (method of Macfadyen 

 and Roland), then extracted with 1 to 1000 potassium hydrate, 

 centrifugalized to remove fragments of the organisms and filtered. 

 A small amount of the filtrate, 0.5 to 1 c.c. in rabbits, 0.1 to 1 c.c. in 

 guinea-pigs, produced death when injected intravenously or intra- 

 peritoneally. The toxicity of the filtrate was roughly proportional 

 to the virulence of the organisms for rabbits. Heating the filtrate 

 to 55 C. for an hour, or exposure to chloroform vapor for the same 

 time reduced the toxicity of the preparation very considerably. Neu- 

 feld and Dold 5 and Rosenow 6 obtained toxic substances from pneumo- 

 cocci, the former by extraction of the organisms in 0.1 per cent, 

 lecithin in physiological salt solution, the latter by simple autolysis, 

 which induced symptoms in guinea-pigs suggesting acute anaphy- 

 laxis. Cole 7 has repeated these experiments with results that were 

 irregular: thus, of 213 guinea-pigs injected with extracts of pneumo- 

 cocci in salt solution, 8 died acutely with symptoms resembling acute 

 anaphylactic shock, 83 died within twelve hours, the remainder were 

 negative. Cole concludes that extracts of pneumococci in salt solu- 

 tion may be toxic, but not uniformly so. The exact conditions under 

 which these solutions become toxic are unknown. Solutions of 

 pneumococci dissolved in dilute solutions of bile salts were found to 

 be very constantly toxic. 8 The intravenous injection of these solu- 

 tions into rabbits and guinea-pigs elicits symptoms resembling closely 

 those of acute anaphylaxis. Many of the animals die acutely. 



1 Zeit. klin. Med., 1891, xx, 165. 



2 Jour. Path, and Bact., 1897, iii, 214. 

 . 3 Ann. Inst. Past., 1892, vii, 259. 



4 Cent. f. Bakt., Orig., 1907, xliii, 30. 



5 Berl. klin. Wchnschr., 1911, xlviii, 1069. 



6 Jour. Infec. Dis., 1911, ix, 190. 



7 Jour. Exp. Med., 1912, xvi, 644. 



8 Casagrandi (quoted by Pribram: Kolle and Wassermann Handb., 2 ed., 1913, iia, 

 1350) states that normal rabbit blood contains antihemolysins. 



