2b6 BACTERIA 



Morphology and Stains. Threads are thick and short, or long 

 and slender, depending upon the medium on which they grow. In 

 bouillon the threads are thin and long, on blood serum, short and 

 thick. When stained there is distinct beading and fragmentation 

 of the protoplasm. 



FIG. 73. Streptothrix Candida. (Kolle and Wassermann.) 



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 60 C. 70 C. 

 for an hour; moist heat, 60 C. however, kills them after an hour. 

 It is a strict aerobe. 



Cultures. On Lbffler'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- 



