, Volume 64, Issue 1, pp 29–33 | Cite as

Role of the conidium in dimorphism of Blastomyces dermatitidis

  • Robert G. Garrison
  • Karen S. Boyd


Fine details of yeastlike cell development of Blastomyces dermatitidis from its conidium are described and illustrated by electron micrographs. When cultured in an enriched medium at 37 °C, conidia of two strains of B. dermatitidis readily underwent ultrastructural changes consistent with mycelial to yeast dimorphism. Although hyphal cells contained in the conversion cultures were observed consistently to undergo profound degenerative changes, the conidia rapidly germinated to give rise to short germ tubes which subsequently enlarged to form intermediate yeast mother cells (YMC). The wall of the germ tube arose from the innermost layer of the wall of the germinant. During the transition globoid osmiophilic inclusions of unknown origin and function were observed in vacuolated areas of the germ tube and YMC cytoplasm. Yeastlike daughter cells then budded from the intermediate YMC. Since transformation was readily accomplished under in vitro conditions favoring mycelial to yeast dimorphism, it is suggested that the conidium of B. dermatitidis represents the primary infective unit of this pathogenic fungus.


Pathogenic Fungus Degenerative Change Cell Development Daughter Cell Unknown Origin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Dr. W. Junk bv - Publishers 1978

Authors and Affiliations

  • Robert G. Garrison
    • 1
    • 2
    • 3
  • Karen S. Boyd
    • 1
    • 2
    • 3
  1. 1.The Research ServiceVeterans Administration HospitalKansas City
  2. 2.The Departments of MicrobiologyUniversity of Missouri-Kansas City School of DentistryUSA
  3. 3.The University of Kansas School of MedicineKansas CityUSA

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