POISONOUS BACTERIAL PROTEINS 131 



POISONOUS BACTERIAL PROTEINS 



If we filter a bouillon culture of diphtheria bacilli through porce- 

 lain, wash thoroughly with salt solution the bacteria remaining, and 

 collect them thus freed from their secretion products, it will be found 

 that extracts of the bacterial substance or the bodies of the killed bac- 

 teria themselves are quite free from the typical toxin. This indicates 

 that the toxin is eliminated from the bacteria as fast as it is formed, 

 and no considerable quantity is retained within the cell. The bac- 

 terial substance, however, or proteins isolated from it, is found to pro- 

 duce severe local changes when injected into the bodies of animals, 

 necrosis and a strong inflammatory reaction with pus-formation being 

 the chief features. This local effect is not a specific property of the 

 diphtheria bacillus, for other bacterial proteins, including proteins 

 from non-pathogenic bacteria, will produce the same changes; in- 

 deed, many proteins that are derived from vegetable and animal 

 sources have equally marked pyogenic properties. All foreign pro- 

 teins when introduced into the circulation of animals are more or less 

 toxic, and the toxic effects of the bacterial proteins are, for the 

 most part, neither specific nor particularly striking. There are a few 

 pathogenic organisms, however, which seem to produce neither true 

 toxins nor endotoxins, notably the tubercle bacillus and the anthrax 

 bacillus, and with these there may be a relation between their protein 

 constituents and their specific effects. 



Numerous protein substances have been extracted from bacterial 

 cells, particularly nucleoproteins, but also proteins resembling al- 

 bumins, nucleo-albumin, and globulins. In all probability the chief 

 proteins of the bacterial cell are nuelein compounds, wliicli is indi- 

 cated both by their nuclear staining and by the analyses of Iwanoff ; * 

 and many of the nucleoproteins, both of bacterial and non-bacterial 

 origin, cause considerable local inflammatoiy reaction when injected 

 into animals. Tiberti * claims that vaccination with non-lethal doses 

 of the nucleoproteins of anthrax bacilli will protect animals against 

 inoculations of virulent anthrax bacilli. Some of the earlier observa- 

 tions on the toxicity of bacterial proteins were erroneous because im- 

 pure proteins, containing toxins, endotoxins, and ptomai'ns were used. 

 Schittenhelm and Weichardt ^ have found, however, that bacterial 

 proteins are much more toxic than any ordinary proteins, as indi- 

 cated by loss of nitrogen, temperature changes and alterations in the 

 leucocytes of injected animals. 



Vaughan and his students have been able to split off from the 

 bodies of various pathogenic bacteria toxic materials which are stated 

 to resemble in some respects the protamins,^^ although they do not all 



3 Hofmeister's Beitr., 1002 (1), 524. 



4 Cent. f. Bakt., 1006 (40), 742. 

 sMiinch. med. Woch., 1011 (58), 841. 



5a A full review of this work is given in Vaucrhan's "Protein Split Products," 

 Philadelphia, 1013; and in Jour. Lab. Clin. Med., 1916, Vols. 1 and 2. 



