184 



ACTINOMYCES. Bellinger (1877). 



SYNONYMS. RAY-FUNGUS. STRAIILENPILZ (Germ.}. 



Origin. From actinomycosis or lumpy-jaw in cattle, 

 hogs, and in man. 



Form. The exact position of this organism is uncer- 

 tain, but it is closely related to the fungi or moulds. It 

 forms nodules which consist of a whorl of mycelial-like 

 multiple branched threads. These radiate outward from 

 a central point and become club-shaped. In pure cultures 

 only slender, wavy threads are formed, and the club-shaped 

 or swollen ends, so commonly present in tissues are lacking. 



Anilin Dyes. Stain readily with carbolic fuchsine; 

 also by Gram's method. 



Growth. Develops somewhat slowly, requiring sev- 

 eral days in the incubator. 



Streak Cultures. On agar, the growth begins as minute, isolated colo- 

 nies, which slowly enlarge, forming thick, convex, glistening, yellowish 

 masses. These colonies are exceedingly hard and for examination should be 

 crushed between two glass slides previously sterilized by passing several times 

 through the flame. Cover-glass preparations are then made and stained in 

 the usual manner. 



Oxygen requirements. Said to grow best in the 

 absence of air, but grows very well on the surface of agar. 



Temperature. Grows only at or near the body 

 temperature. 



Pathogenesis. In rabbits, intraperitoneal injection 

 of the pure culture produces typical actinomycotic nodules 

 on the peritoneum, mesentery, intestinal walls, etc. 



