314 



MEDICAL MYCOLOGY 



form chains of spores. These sporogenous hyphae are coiled, the 

 rotation of the helix and the type of coiling being characteristic 

 of the species. 



The best known of the species pathogenic to man is Actino- 

 myces bovis, described by Harz (1879) in 1879. It causes a 

 chronic disease known to the medical profession as actinomycosis 

 and characterized by the formation of suppurative tumors. 



Fig. 69. Actinomyces bovis. A. Filamentous appearance of colony in cul- 

 ture. B. The hyphae from culture when smeared on microscopic slide 

 fragment to become bacteria-like. C. "Sulphur granule" taken from abscess 

 and stained to show peripheral clubs. D. View of clubs with magnification 



slightly increased over that in C. 



Farmers and cattlemen are more commonly afflicted than are 

 persons in other occupations. The disease involves not only man 

 but also such other animals as horses, cows, sheep, and pigs, as 

 well as many species of wild animals. In cattle the disease is called 

 "lumpy jaw," "wooden tongue," or "sarcoma of the jaw." In 

 man A. bovis may involve any part of the body but is most com- 

 mon on the head and neck. About 60° of all cases are cervico- 

 facial, 14 are thoracic, and 8 to 18°o involve the abdominal 

 organs. 



Many cervico-facial cases arise from dental defects or after 

 the extraction of teeth. Studies by Emmons (1935) show that in 

 a high percentage of instances the causal fungus can be isolated 

 from the normal mouth, carious teeth, tonsillar crvpts, or drain- 



