34 

 BACILLUS PRODIGIOSUS. 



MONAS PRODIGIOSA OF EHRENBERG. MICROCOCCUS PRODIGIOSUS 

 OF OLDER WRITERS. 



Origin. Found on starchy substances, rice, potatoes, 

 moist-bread ; also on meat, albumin, milk, etc. May form 

 at times local epidemics, infecting foods as bread, meat, 

 sausages, with production of pink or red color. " Bleed- 

 ing" bread or wafers. 



Form. Short rod, slightly longer than its width. 

 May form short threads, especially in slightly acid media. 

 Usually sinirle or in pairs. 



Motility. Ordinarily shows no motion, except a 

 marked Brownian movement. In acid or very dilute media 

 appears to have slight motion. 



Sporulation. Has not been observed. Possesses 

 marked resistance to desiccation. 



Anilin Dyes. Stain readily. 



Growth. Very rapid. 



Gelatin Plates. Deep colonies, round or oval, with sharp border and 

 light brown color. Surface colonies irregular, rough border, granular, with 

 reddish centre, and surrounded by clear, liquefied gelatin. 



Stich Cultures. Rapid, funnel-shaped liquefaction, extending along 

 entire line of inoculation. Red scum forms on surface of liquid, eventually 

 settles and entire contents of tube colored bright red. 



Streak Cultures. On agar, forms abundant, moist, spreading growth, 

 having an intense red color which is non-diffusible. On potatoes, especially 

 rapid, slimy growth, with marked pigment production. The pigment, when 

 old, has a metallic fuchsine-like lustre. Odor of trimethylamine. On blood 

 serum, growth as on agar, with liquefaction. 



Milk, Growth takes place and the pigment is held in solution by the fat 

 globules. 



Oxygen requirements. Is a facultative anaerobe. 

 Pigment is formed only in presence of oxygen. 



Temperature. Grows best at ordinary room tem- 

 perature. In incubator ceases to form pigment, and may 

 temporarily lose this property, i. e., becomes attenuated. 



Behavior to Gelatin. Rapidly liqueties as result 

 of formation of soluble ferment. This liquefying property 

 may be diminished or temporarily lost by growth in acid 

 media. 



Aerogenesis. Strong odor of trimethylamine on 

 potatoes. 



Pathogenesis. No pathogenic power. Its soluble 

 products in large amounts may have a toxic action. The 

 cellular proteids may induce suppuration. Animals in- 

 susceptible to malignant oedema are rendered susceptible 

 by injection of B. prodigiosus. Rabbits inoculated with 

 anthrax are saved by injection of B. prodigiosus. 



