730 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



in diameter, and show true branching (Fig. iS4)- The young colony is a loose 

 mass of filaments; older colonies become dense and felted. Rod-shaped and spherical 

 forms appear in artificial cultures, and some filaments develop conidia. Cultures, 

 - especially those containing the roundworms, are very resistant to heat, light, drying 

 and disinfectants. Stains easily. Tissue section stained with carmine followed by 

 Gram's method gives good results, the thread showing dark and clubs red. Carmine 

 followed by Weigert gives a beautiful stain. May be recognized as visible granules 

 found floating in the pus in case of suppuration,, or embedded in tissue. These 

 granules vary in color; some are clear or yellow; others are quite dark. The colony 

 as it appears in tissue section or pus smear consists of a rosette arrangement. The 

 central portion of the colony is a derlse mass of mycelium and spherical bodies. 

 From this felted central mass, there extend rays or club-like bodies. Club-shaped 

 enlargements at the ends of filaments frequently appear and are regarded as a 

 distinguishing characteristic of Actinomyces. This organism is usually destroyed 

 at 75° for thirty minutes. Final diagnosis must rest upon actual demonstration 

 under the microscope which is not difficult. The granular masses may be washed 

 in normal salt solution; and examined unstained, or stained in diluted carbol fuchsin. 



Escape from the diseased body is usually in pus discharged from 

 actinomycotic abscesses. In case of open lung or intestinal lesions 

 it may be discharged through the trachea or intestines. 



Very little is known concerning the disseminating agents except 

 that the sharp awns of barley and some similar bodies from other 

 wild grasses have been found carrying actinomycotic infection. There 

 appears good reason for beUeving that such awns frequently serve to 

 spread the disease. Actinomycotic pus scattered over fodder, mangers, 

 and feed racks probably serves indirectly as a source of dissemination. 



Actinomycosis is not a disease of rapid or extensive dissemination. 

 Control work is usually confined to isolation, to proper disposition 

 of diseased animals and. to suitable disinfection. It is recognized in 

 sanitary legislation that very many actinomycotic carcasses are fit 

 for food purposes and should not be condemned. 



AcTiNOBACiLLOSis. — ^ActinobaciUosis is probably to be distinguished 

 from, actinomycosis. It is very similar in subjects affected, in history 

 and clinical evidence, but apparently different as to specific cause. 

 The cause of actinobacillosis seems to be a very small bacterium found 

 also in rosette-Uke masses resembling those of Actinomyces. 



Mycetoma (Madura Foot)* 



This disease is endemic in India, especially in Madura, and is found 

 in other warm countries. 



• Prepared by Edward Fidlar. 



