494 PATHOGENIC AEROBIC BACILLI 



107. BACILLUS OF DEMME. 



Obtained by Demme (1888) from the fluid contents of the tumors and 

 pustules of erythema nodosum, and also from the blood of the affected indi- 

 vidual. 



Morphology. Bacilli with round ends, from 2.2 to 2.5 // long and 0.5 to 

 0.7/u broad; usually collected in smaller or larger groups. 



Stains with the usual aniline colors and by Gram's method. 



Biological Characters. An aerobic (facultative anaerobic?) bacillus, 

 which does not grow in nutrient gelatin at the room temperature. Grows 

 in nutrient agar at 35 to 37 C. Forms spores. In agar plates, at 35 to 37 

 C., smooth, spherical, shining white colonies are formed in from forty-eight 

 to sixty hours, whicli at the end of six or seven days may have the size of a 

 small coin five centimes; these are marked by lines radiating from the 

 centre, which are slightly elevated above the surface of the colony and have 

 a silvery lustre by obliquely reflected light; the margins of the colony are 

 fringe-like, and after ten or twelve days conical offshoots are given off from 

 this thready margin. In agar stick cultures growth occurs along the line 

 of puncture in the form of a thorny column which has a paraffin-like 

 lustre. 



Pathogenesis. According to Demme, when injected subcutaneously into 

 guinea-pigs, or by rubbing pure cultures into the scarified skin, an eruption 

 occurs which resembles that of erythema nodosum and is followed by a 

 gangrenous condition of the skin. Rabbits, dogs, and goats proved to be 

 refractory. 



108. BACILLUS CEDEMATIS AEROBICUS. 



Synonym. A new bacillus of malignant osdema (Klein). 



Obtained from garden earth by inoculation in guinea-pigs. 



Morphology. Bacilli from 0.8 to 2.4 // in length and 0.7 u thick; grow 

 out into long filaments. 



Stains with the usual aniline colors, but not by Gram's method. 



Biological diameters. An aerobic and facultative anaerobic, non-lique- 

 fying, motile bacillus. Does not form spores. Grows at the room tempera- 

 ture in the usual culture media. Upon gelatin plates, at the end of twenty- 

 four hours, small, gray, punctiform colonies are developed ; at the end of 

 forty-eight hours the superficial colonies are seen as flat, grayish, transparent 

 plaques, the margins of which are thin and irregularly notched ; these attain 

 a diameter of several millimetres in the course of a few days. The deep colo- 

 nies do not exceed the diameter of a pin's head ; they remain spherical, and 

 by transmitted light have a brownish color. In gelatin stick cultures a, 

 white line of growth is developed along the track of the inoculating needle, 

 and at the bottom of this isolated, punctiform colonies are seen ; upon the 

 surface a flat, thin, transparent, grayish layer with a dentate margin is 

 developed. Upon the surface of agar a smeary, grayish-white stripe is de- 

 veloped along the impfstrich. Alkaline bouillon, at the end of twenty-four 

 hours at 37 J C., is densely clouded, and later contains numerous flocculi, but 

 no pellicle upon the surface ; at the end of twenty-four hours the reaction 

 becomes strongly alkaline. Upon potato a viscid, yellowish stripe is devel- 

 oped along the line of inoculation. In deep cultures in nutrient gelatin gas 

 bubbles are developed in from twenty-four to forty-eight hours; these are 

 attached to the isolated colonies. 



Pathogenic for guinea-pigs, rabbits, and white mice. The animals die 

 within twenty four hours when very small quantities are injected subcu- 

 taneously into guinea-pigs they may live for two or three days and sometimes 

 recover. The lethal dose of a bouillon culture is from one-fourth to one- 

 half cubic centimetre, but one drop of the cedematous fluid from the subcu- 

 taneous connective tissue of an inoculated animal is infallibly fatal. In 

 guinea-pigs an extensive inflammatory oedema is produced by subcutaneous 

 inoculations ; the spleen is but slightly enlarged. In rabbits but slight oedema 



