168 

 BACILLUS PYOCYANEUS. Gessard (1882). 



BACILLUS OF GREEN OK BLUE PUS. 



Origin. In green pus. The color forms on exposure 

 to air. Several varieties have been described. 



Form. Small narrow rod resembling that of blue 

 milk. At times it has almost a coccus form. The ends 

 are rounded ; mny form short threads of 4-6 cells. 



Motility. Actively motile. 



Sporulation. Has not, been observ-ed. 



AnilinDyes. Stains easily also by Gram's method. 



Growth. Is rapid and abundant. Oxygen is neces- 

 sary to the formation of the pigment. 



Plates. On gelatin plates a green fluorescing pigment develops quite 

 early. The surface colonies at first tend to spread then produce funnel-shaped 

 liquefactions. The deep colonies appear as round^granular masses with ser- 

 rated borders. 



Mich Cultures. In gelatin tubes funnel-shaped liquefaction results. The 

 upper layer is at first green but later the entire contents are colored. In very 

 old cultures the color changes to a brownish black. A scum forms on the sur- 

 face. 



Streak Cultures. On agar a moist, slimy, yellowish growth develops 

 and the medium itself becomes bright green. When very old the agar be- 

 comes dark colored and the growth has a peculiar scaly, metallic appearance. 

 On potatoes a yellowish green or brownish slimy growth forms. 



Milk. Grayish yellow spots form on the surface; the casein is precipi- 

 tated and subsequently peptonized with production of ammonia. 



Oxygen requirements. Is a facultative anaerobe. 

 No growth under mica plates, but can grow in the body. 



Temperature. Grows at ordinary temperature, also 

 in the incubator. 



Behavior to Gelatin. Liquefies rapidly. 



Attenuation. Artificial cultures diminish in viru 

 lence. 



Immunity. After recovery from the effects of in- 

 jection of small amounts of the culture the animal is 

 immune. Sterilized cultures also induce immunity. 



Pathogenesis. Subcutaneous injection, in guinea- 

 pigs and rabbits, of about 1 c.c. of a fresh bouillon culture 

 produces a rapidly spreading oedema, purulent inflnmma- 

 tion and death. Bacilii present in the tissues, blood, 

 organs, etc. Intra peritoneal injections produce purulent 

 peritonitis and death. Sin* 11 amounts produce less marked 

 results and recovery. Cure of animals infected with an- 

 thrax by inoculation with B. pyocyaneus. 



