308 Wound Infection; Suppuration 



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

 agar, upon which much stress has recently been laid by 

 Martin,* is the formation of crystals in fresh cultures. 

 Crystal-formation in cultures of other bacteria usually takes 

 place in old, partially dried agar-agar cultures, but Bacil- 

 lus pyocyaneus often produces crystals in a few days upon 

 fresh media. In my experience 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 

 cloudiness, 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 Bolandf has 

 shown this to be a transformation product 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 0.2-0.5 c.c. when intraperitoneally injected into 

 guinea-pigs. The animals show peritonitis and punctiform 

 hemorrhages on the serous membranes. 



Bullock and HunterJ found that B. pyocyaneus also 

 produces a hemolytic substance, pyocyanolysin, by which 

 corpuscles of man, oxen, sheep, apes, rabbits, cats, rats, 

 dogs, and mice are dissolved. The peculiar substance was 

 produced in greatest quantity in virulent cultures three or 

 four weeks old. Jordan believes that this hemolytic 

 property of the cultures depends solely upon the intense 

 alkali formed in old pyocyaneus cultures. 



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



t Ibid., etc., Bd. xxv, 1899, p. 897. 



J Ibid., xxvm, 1900, p. 865. Ibid., Bd. xxxm, Ref. 1903. 



