802 PATHOGENIC MICROORGANISMS 



does not produce gas or acid, but renders broth slowly alkalin. 

 He states that in its bio-chemical aspects it approaches the pyo- 

 cyaneous group, especially in regard to its strict aerobiosis and its 

 lack of activity on sugars. In this respect, Smith calls attention 

 to the fact that it is similar to the bacillus of cattle abortion. Smith 

 compared the organism with a culture of the B. bronchisepticus sent 

 him by Torrey which was supposed to be the cause of distemper 

 in dogs, and found that his bacillus agreed with Torrey 's strain 

 in every particular, in regard to morphology and cultural char- 

 acteristics. 



He also identified his guinea-pig bacillus with an organism 

 observed by Mallory in the ciliated epithelium of the air tubes in 

 fatal cases of whooping cough. 



In his description of the growth of his guinea-pig organism on 

 potato, Smith calls attention to the similarity of this bacillus to 

 the growth on potato of the bacillus of cattle abortion of Bang. 



Bacillus Pyocyaneus. It is a matter of common surgical ex- 

 perience that many suppurating wounds, especially sinuses of long 

 standing, discharge pus which is of a bright green color. The fact 

 that this peculiar type of purulent inflammation is due to a specific 

 chromo genie microorganism was first demonstrated by Gessard 22 in 

 1882. The bacillus which was described by Gessard has since become 

 the subject of much careful research and has been shown to hold a 

 not unimportant place among pathogenic bacteria. 23 



Morphology and Staining. Bacillus pyocyaneus is a short rod, 

 usually straight, occasionally slightly curved, measuring, according 

 to Fliigge, about 1 to 2 micra in length by about 0.3 of a micron 

 in thickness. The bacilli are thus small and slender, but are subject 

 to considerable variation from the measurements given, even in one 

 and the same culture. "While ordinarily single, the bacilli may be 

 arranged end to end in short chains of two and three. Longer 

 chains may exceptionally be formed upon media which are especially 

 unfavorable J!or its growth, such as very acid media or those con- 

 taining antiseptics. 



Spores are not found. The bacilli are actively motile and possess 

 each a single flagellum placed at one end. 



Bacillus pyocyaneus is stained easily with all the usual dyes, but 

 is decolorized by Gram's method. Irregular staining of the bacillary 



22 Gessard, Th&se de Paris, 1882. 



in, "La maladie pyocyanique, " Paris, 1889. 



