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INFECTIONS CAUSED BY MOLDS 



cell. Usually a cell bears a single bud, but one can also find two 

 or more buds arising from one end of a cell or observe a chain of 

 cells representing buds' which have failed to separate. The opening 

 between the parent cell and the young bud (and the plane of attach- 

 ment between two mature cells) has a greater diameter than is seen 

 in the typical budding of yeasts where the bud is typically pinched 

 off and successive buds form at or near the same spot. 



Fig. 90. Budding yeast-like cells of Blastomyces dermatitidis, in a wet prepara- 

 tion of pus from a case of blastomycosis. 



The cells of Blastomyces dermatitidis are larger and have thicker 

 walls than those of Candida albicans and the yeasts. They lack the 

 conspicuous capsule produced by Cryptococcus neoformans and are 

 less uniform in shape than the spherical cells of that fungus. B. 

 dermatitidis has sometimes been confused with Coccidioides immitis, 

 but careful search will reveal budding or pseudobudding which is 

 never observed in the latter. No endospores or ascospores are formed 

 by B. dermatitidis. 



Cultures. The fungus grows slowly, but if primary cultures are 

 not too heavily contaminated it can be isolated in culture readily. 

 Pus can be spread on blood agar plates and incubated at 37° C, 

 wherupon the fungus grows in a manner closely resembling its para- 

 sitic growth phase. Colonies are yellowish white to tan, somewhat 

 mealy or waxy, and of a vermiculate or worm-cast type. A micro- 



