Bacillus Pyocyaneus 323 



been made the subject of a careful investigation by Jordan.* Its 

 formula, according to Ledderhose,f is Ci 4 Hi 4 N 2 O. 



A well-known feature of the growth upon fresh agar-agar, upon 

 which much stress has recently been laid by Martin, { is the forma- 

 tion of crystals in fresh cultures. Crystal formation in cultures of 

 other bacteria usually takes place in old, partially dried agar-agar, 

 but Bacillus pyocyaneus often produces crystals in a few days upon 

 fresh media. Freshly isolated bacilli show this power more markedly 

 than those which have been for some time part of the laboratory 

 stock of cultures and frequently transplanted. 



Bouillon. In bouillon the organism produces a diffuse cloudi- 

 ness, a fluorescence, and sometimes an indefinite thin pellicle on the 

 surface. 



Potato. Upon potato a luxuriant greenish or brownish, smeary 

 layer is produced. 



Milk. Milk is coagulated and peptonized. It is slightly acid 

 for the first day or two, then becomes alkaline again. 



Metabolic Products. Apart from the pyocyanin and fluorescin, 

 the former blue, the latter green, cultures of this organism frequently 

 turn red brown. This suggested the formation of a third pigment, 

 but the work of Boland has shown this to be a transformation prod- 

 uct of pyocyanin common in old cultures. 



The organism produces a curdling ferment, a fibrin- and casein- 

 dissolving ferment, a gelatin-dissolving ferment, and a bacteriolytic 

 ferment, the pyocyanase of Emmerich and Low. 



It also produces, under favorable conditions, a toxin which has 

 been studied by Wassermann, who found it fatal in doses of 0.2 

 to 0.5 cc. when intraperitoneally injected into guinea-pigs. The 

 animals show peritonitis and punctiform hemorrhages on the serous 

 membranes. 



Bullock and Hunter|| found that Bacillus pyocyaneus also pro- 

 duces a hemolytic substance, pyocyanolysin, by which corpuscles of 

 man, oxen, sheep, apes, rabbits, cats, rats, dogs, and mice are dis- 

 solved. The peculiar substance was produced in greatest quantity 

 in virulent cultures three or four weeks old. Jordan** believes that 

 this hemolytic property depends solely upon the intense alkali 

 formed in old cultures. Gheorghewskiff found a leukocyte-destroy- 

 ing substance in the cultures. 



In addition to the metabolic pigments mentioned, the organism 

 produces toxins. Wassermann tt found that filtrates of old cultures 

 were more toxic for guinea-pigs than the endotoxins made by lysis 



* "Journal of Experimental Medicine," 1899, vol. rv. 



t "Deutsche Zeitschr. f. Chirurgie," 1888, Bd. xxvm. 



j "Centralbl. f. Bakt.," April 6, 1897, xxi, p. 473. 



"Centralbl. f. Bakt.," 1899, Bd. xxv, p. 897. 



|| Ibid., xxvm, 1900, p. 865. 

 ** Ibid., Bd. xxxm, Ref. 1903. 

 ft "Ann. de 1'Inst. Pasteur," 1899, xm. 

 Jt "Zeitschrift fur Hygiene, 1896, xxn. 



