PYOCYANEUS BACILLUS l8l 



PYOCYANEUS BACILLUS 



Bacterium pyocyaneus. 



Bacillus Pyocyaneus (Fig. 50). 



Bacillus of Blue Pus. Also called Pseudomonas pyocyanea. 



An organism of minor importance as a pathogenic agent, that 

 is often met with in groin or axilla. 



Morphology and Stains. Slender rods, often growing into 

 thread-like forms. Exhibits pleomorphism. Sometimes is 

 rounded and cocci-like, is motile, has a polar flagellum, and 



FIG. 50. Bacillus pyocyaneus. ^(Kolle and Wassermann.) 



no spores. Stains with all the basic aniline dyes, but not with 

 Gram's method. 



Oxygen Requirements. Usually a strict aerobe. 



Cultures. Grows on all the common culture media luxuriantly, 

 at room and incubator temperatures. It elaborates two pig- 

 ments, a water-soluble greenish bacteriofluorescein, and a chloro- 

 form soluble pigment, a beautiful blue in color, called pyocyanin. 

 On gelatine plates it produces yellowish-white to greenish, yellow 

 colonies which liquefy the gelatine, causing crater-like excavations 

 about the colonies. Gelatine stab cultures rapidly liquefy along 



