376 



ACTINOMYCOSIS 



The clubs are formed by the deposition of material upon the 

 peripheral hyphae of the granule. They are not specific and similar 

 material is deposited on other microorganisms which form similar 

 granules. The commonest example is in actinobacillosis described 

 by Lignieres and Spitz. In this disease of cattle a Gram-negative 

 bacillus, Actinobacillus Ligniersi, grows in clusters surrounded by a 

 sheath of clubs which sometimes branch. The resemblance to acti- 

 nomycotic granules is very close until a Gram-stained smear is ex- 



FiG. 136. Left, section of granule of Actinomyces bovis; right, Gram-stained 



smear of granule of A. bovis. 



amined. There is a close clinical resemblance between the two 

 diseases. 



Magnusson ^'^ has made an extensive investigation of actinomy- 

 cosis in cattle and swine, and has come to the conclusion that a 

 considerable number of the cases which have been in the past diag- 

 nosed as actinomycosis are not caused by Actinomyces but by this 

 bacillus. 



A second bacterial disease in which club-bearing granules are con- 

 spicuously present is Staphylococcic actinophytosis.'' This has been 

 especially established by Magrou in observations of this disease 

 which is usually known as botryomycosis and is most often seen in 

 horses. This is a chronic inflammatory disease of the subcutaneous 

 tissues associated with the presence of certain granules of lobulated 

 structure which were formerly mistaken for a fungus, Botryomyces. 

 Magrou showed that these granules are in reality small colonies of 

 Staphylococcus aureus, surrounded by an acid-staining sheath of 



