380 ACTINOMYCOSIS 



are much smaller and finer in structure than those in actinomycosis 

 proper. 



A^. madurae may be readily cultivated on ordinary media and is 

 aerobic. The growth on solid media is usually somewhat mealy or 

 membranous and wrinkled, generally creamy white or grey in color, 

 though at times cultures develop a crimson color. The aerial my- 

 celium is very scant or lacking. There is no soluble pigment on any 

 medium. Starch is digested, milk is peptonized, and gelatin is lique- 

 fied. The mycelium undergoes fragmentation in old cultures, but 

 it is less fragile than Actinomyces bovis. No spirals are formed in 

 the aerial mycelium and there are no spores. 



Madura foot may occasionally, though very rarely, extend up the 

 leg by way of the lymphatics, but does not tend to metastasize to 

 other parts of the body and endanger life. On the other hand, it 

 tends to progress steadily and does not respond to medication. The 

 best treatment is amputation. 



Other actinomycetes causing mycetoma pedis are N. mexicana 

 (reported by Gonzalez Ochoa ^° in several cases in Mexico) , N. soma- 

 liensis, and A^. Pelletieri. There are, besides these, many other species 

 names in the literature, some based upon a single isolation. The 

 validity of these names can be determined only by a critical com- 

 parison of many strains. These fungi are extremely variable, and 

 a multiplicity of names is the inevitable result of describing as a new 

 species each strain which differs in minor and variable character- 

 istics. 



Acidfast Actinomycetes. The acidfast actinomycetes form a group 

 which is not of very great practical importance, because infections 

 caused by them are rare but of great scientific interest since they 

 form a distinct connecting link between the bacteria proper and the 

 higher fungi. 



A number of apparently different species of acidfast actinomycetes 

 have been isolated from both domestic animals and man. They all 

 bear a rather close resemblance to each other in their morphological, 

 cultural, and pathogenic properties, tending to form mealy growths 

 on culture media, with readily fragmenting mycelium, and forming 

 pseudotubercles in the tissues. 



The acidfastness of these forms is not so pronounced as that of the 

 tubercle bacillus, i.e., they may be decolorized with acids in a shorter 

 period of time; but it is distinct enough to demonstrate clearly the 

 organisms in tissues or exudates. In general they are much more 

 definitely acidfast in tissues and exudates than in cultures, but they 

 tend to lose this property after continued cultivation. 



