STREPTOTHRIX 223 



thick. When stained there is distinct beading and fragmentation 

 of the protoplasm. 



There is true branching of an irregular type, which is best seen 

 in liquid media. These threads often produce spores on culture 

 media. The threads often disappear in old cultures, leaving only 

 the spores, which stain with carbol-fuchsin and do not decolorize. 

 The threads stain by Gram's method, and Gram-Weigert method. 

 The threads are not acid-fast. 



Vital Characteristics. These organisms live for years in cul- 

 ture media after it is dry. Spores resist dry heat at 6oC. to 

 7oC. for an hour; moist heat, 6oC. however, kills them after an 

 hour. It is a strict aerobe. 



Cultures. On Loffler's blood serum, according to Tuttle, this 

 organism grows slowly in whitish colonies, which finally become 

 yellow. The adult colonies adhere to the serum. On agar it 

 grows rapidly and characteristically. The colonies are yellowish- 

 white and adhere to the agar. In Bouillon. It develops slowly 

 on the surface of the medium. Fluffy tufts, or balls, are formed, 

 that sink to the bottom of the tube. The growth is whitish. 



Pathogenesis. For rabbits and guinea pigs this organism is 

 pathogenic, producing abscesses, tubercles, induration, etc. It is 

 a pus forming organism. 



In animals the spontaneous disease appears, best known as 

 "farcin du boeuf," as ulcerative or infiltrative lesions of lungs 

 and skin. 



In man, the disease picture is like that of tuberculosis. It 

 causes abscesses, adenitis, indurations of the skin, endocarditis, 

 and pleuritic inflammation. Many grayish tubercles were found 

 that resembled the lesions produced by the tubercle bacillus. 

 Cavity formation has been described. 



This organism may act as a secondary infecting agent in tuber- 

 culosis of the lungs. Tuttle reviews twelve cases, all of which 

 were fatal. 



In examining sputum from tuberculous cases, in which the typ- 



