ACTINOMYCETES IN MYCETOMA PEDIS 379 



ception that actinomycosis is more frequent in rural areas because 

 farmers are exposed to the fungus on straw and hay (where actually 

 it has never been found) is a striking example of a medical error 

 arising from an early erroneous identification of a culture being per- 

 petuated by repetition. 



Habitat in Nature. From the excellent early studies of Wright ^* 

 it has been known that Actinomyces bovis is present in carious teeth. 

 Later studies of Lord/^ Naeslund,^^ Emmons,^ Slack,-^ and others 

 have confirmed the early observations and shown that it is often 

 present in tooth cavities, on the surface of teeth, and in the crypts of 

 tonsils. Rosebury has recently reviewed most of the literature on this 

 subject. Demonstration of the fungus and its isolation in pure cul- 

 ture from the oral cavity may be difficult because of the presence 

 of other microorganisms. Emmons in an examination of several hun- 

 dred tonsils found the fungus present in 30 to 40 per cent and isolated 

 it in pure culture from about 10 per cent of the pairs of tonsils ex- 

 amined. The fungus is present in the granules which lie free in the 

 crypts of tonsils. These are not cases of actinomycosis. There is 

 no infection and the fungus grows saprophytically, exciting little or 

 no host reaction. The granules invariably have a mixed bacterial 

 flora consisting largely of Streptococci, fusiform bacilli, Leptotrichia, 

 spirillae, and spirochetes. A. bovis may be inconspicuous or lacking, 

 but in some granules it may be the principal organism present. 



Strains of A. bovis isolated from the oral cavity in the absence 

 of clinical actinomycosis are indistinguishable from strains isolated 

 from the disease, and have been used in the production of experi- 

 mental actinomycosis in animals. The pathogen exists commonly as 

 a saprophyte in the oral cavity. It has never been isolated from 

 soil and vegetation. 



Actinomycetes in Mycetoma Pedis. Thirteen species of actino- 

 mycetes have been recovered from cases of mycetoma pedis (Madura 

 foot) according to Gammel ^ and, in a number of cases reported since 

 that review, other fungi have been described. Most of these are 

 Hyphomycetes and were discussed in Chapter VII. The fungus of 

 interest in the present discussion is Nocardia madurae, isolated and 

 named by Vincent. 



The granules of N. madurae as examined in pus from a case of 

 INIadura foot have in general the same structure as the sulphur gran- 

 ules from the lumpy jaw type of actinomycosis, consisting of a central 

 basic staining portion composed of a dense meshwork of the fine 

 filaments and a peripheral zone of acid-staining clubs. These bodies 



