806 Actinomycosis 



The fungus is of sufficient size to be detected in pus, 

 etc., by the naked eye. It can be colored, in sections of 

 tissue, by the use of Gram's or Weigert's stain. Tissues 

 pre-stained with carmin, then by Weigert's method, show 

 beautifully. 



Cultivation. The actinomyces fungus may be grown 

 upon all the artificial culture media, as has been fully shown 

 by Israel,* Wolff, and others. 



To obtain a pure culture, material containing the actino- 

 myces granules, secured so as to be as free as possible from 

 contaminating micro-organisms, is crushed between glass 

 plates or in a mortar, and the crushed fungi transferred 

 to plates or tubes as desired. The colonies appear as small 

 gray dots, and consist of a translucent, radiating filamentous 

 network. If kept for a few days at 37 C. they become 

 opaque and nodular, with radiating processes about the 

 periphery. Still later they develop a whitish downy ap- 

 pearance from the formation of short aerial hyphae. The 

 best growth occurs when free access of oxygen is permitted. 



Blood-serum. Upon blood-serum the nodular growths 

 present a yellowish or rust-red color, and are surrounded 

 with a whitish down of fine threads. The colonies adhere 

 closely to the culture media and are so firm that they crush 

 with difficulty. If the surface be scraped, spores and fine 

 threads may be secured. If the mass be crushed, branched 

 filaments may be secured. The colonies become confluent 

 in the course of time, and a thick wrinkled membrane is 

 produced. The growth liquefies blood-serum. 



Gelatin. In gelatin puncture cultures an arborescent 

 growth occurs and the gelatin is liquefied. 



Agar-agar. Upon agar-agar and glycerin agar-agar the 

 growth is similar to that upon blood-serum. The agar-agar 

 turns brown as the culture ages. 



Bouillon. In bouillon the growth occurs in the form 

 of large granules if allowed to stand quietly; of numerous 

 small granules if frequently shaken up. The granules are 

 similar in structure to those formed upon the dense media. 

 The bouillon does not become clouded. 



Potato. Upon potato the growth resembles that upon 

 blood-serum, but is slower in developing. The color is red- 

 dish-yellow and the white down early makes its appearance. 



Eggs. The organism can also be grown in raw eggs, into 

 * "Virchow's Archives," cxv. 



