MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 781 



Actinomyces bovis grows rapidly on a variety of laboratory media. On glycerin 

 agar the colonies develop into transparent drop-like bodies in four or five days at 

 37. Old colonies become white or yellowish with a powdery surface. The cultural 

 and other peculiarities vary much and according to the variety under observation. 

 Some varieties appear distinctly aerobic and others anaerobic. As a rule it liquefies 

 gelatin growing in spherical masses which settle to the bottom of the liquid. Fila- 

 ments appear in artificial growth which are very long and slender, and about 5/1 

 in diameter, and show true branching (Fig. 165). The young colony is a loose 

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

 forms appear in artificial cultures. Cultures, especially those containing the round 

 forms, 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 beau- 

 tiful 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 dense 

 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 fre- 

 quently 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. 



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. 



ACTINOBACILLOSIS. Actinobacillosis 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- like 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 Pidlar, 



