Fungi: Growth Patterns and Dimorphism
No topic is too basic to cover again. Here is an infographic I made describing the difference between mold-dominant, yeast-dominant, and dimorphic growth--three different growth patterns observed during the cultivation of fungi.
For MOLDS, their growth is characterized by hyphal growth at both environmental and body temperature. For YEASTS, their growth is characterized by bacterial-like growth (i.e.: colonies are soft and cells do not exhibit hyphae) at both environmental and body temperature. For DIMORPHIC fungi, their colony morphology changes depending on their incubation temperature. Some remember this through the saying “yeast in the heat, mold in the cold.” The latter most growth pattern makes dimorphic fungi more pathogenic, so it is very important to remember your dimorphic fungi:
Talaromyces marneffei
Coccidioides immitis
Paracoccidioides brasiliensis
Histoplasma capsulatum
Blastomyces dermatitidis
Sporothrix schenckii
How do you remember these bugs? I always say "These Can Possibly Have Both Shapes"
The figure diagraming dimorphic morphologies is not drawn to scale and is not 100% accurate, but it is presented to illustrate the dramatic change in cellular morphology for these dimorphic fungi based on incubation temperature. For more information on the microscopic descriptions of these fungi, their anti-fungal resistance, and more, visit the Mycology Online page from the University of Adelaide: Dimorphic Fungi and Sporothrix
For a great review article, check out this link.
Figures made with Biorender.com
