Bacillus Prodigiosus. 

 MONAS PRODiGiosA, of Ehrenberg'. micrococcus prodigiosus. 



Origin. — Found 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'" 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. 



Oelatin 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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