Bacillus Prodigiosus. 



MONAS PRODIGIOSA, of Ehrenberg. M1CROCOCCUS PRODIGIOSUS. 



ORIGIN. Pound on starchy substances, rice, potatoes, 

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

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

 and sausages, which assume a pink or red color. "Bleed- 

 ing 1 " bread or wafers (p. 116). 



FORM A very short rod, slightly longer than its width. 

 May form short threads, especially in old cultures or in 

 slightly acid media. Usually single or in pairs. 



MOTILITY. Ordinarily shows no motion other than a 

 marked Brownian movement. In acid or very dilute media 

 the slimy character of the growth decreases and, as a 

 result, a slight motion is observed; whips have been 

 demonstrated. 



SPORULATION. Has not been observed. It possesses, 

 however, 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 center, and surrounded by clear, liquefied 

 gelatin. 



Stab culture. Rapid, funnel-shaped liquefaction, extending along 

 the entire line of inoculation. A red scum forms on the surface 

 of the liquid; this eventually settles and the entire contents of the 

 tube are colored bright red. 



Streak culture. On agar, it forms an abundant, moist, spreading 

 growth, having an intense red color which is non-diffusible. On. potato. 

 the growth is especially rapid, and slimy, with marked pigment pro- 

 duction. The pigment, when old, has a metallic, fuchsin-like luster, 

 Odor of trimethylamin. On blood-serum, growth as on agar, with liq- 

 uefaction. 



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

 the fat globules. Coagulation results. 



OXYGEN REQUIREMENTS. It is a facultative anaerobe. 



TEMPERATURE. Grows best at ordinary room temperature. In 

 the incubator it ceases to form pigment, and may temporarily lose 

 this property, i. e., becomes attenuated. 



BEHAVIOR TO GELATIN. Rapidly liquefies as the result of the 

 formation of a soluble peptonizing ferment. This liquefying property 

 may be diminished, or temporarily lost by growth in acid media. 



AEROGENESIS. Strong odor of trimethylamin on potatoes. It 

 ferments sugar solutions. 



PIGMENT PRODUCTION. On various media a bright red pigment 

 forms. This is soluble in alcohol, ether, chloroform, etc. It is formed 

 only in the presence of air, and at ordinary temperature; not at 37. 



PATHOGENESIS. It is not pathogenic. Its soluble products in 

 large amounts may have a toxic action. The cellular proteins may 

 induce suppuration. Animals insusceptible to malignant edema are 

 rendered susceptible by an injection of this bacillus. Rabbits inocu- 

 lated with anthrax are saved by the injection of Bacillus prodigiosus. 



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