Dimorphic fungus
Dimorphic fungi are fungi that can exist in the form of both mold[1] and yeast. This is usually brought about by change in temperature and the fungi are also described as thermally dimorphic fungi.[2] An example is Talaromyces marneffei,[3] a human pathogen that grows as a mold at room temperature, and as a yeast at human body temperature.
Ecology of dimorphic fungi
Several species of dimorphic fungi are important pathogens of humans and other animals, including Coccidioides immitis,[4] Paracoccidioides brasiliensis,[4] Candida albicans,[5] Blastomyces dermatitidis, Histoplasma capsulatum, Sporothrix schenckii, and Emmonsia sp.[6] Some diseases caused by the fungi are:
- sporotrichosis
- blastomycosis
- histoplasmosis
- coccidioidomycosis
- paracoccidioidomycosis
- talaromycosis
- Candidiasis
Many other fungi, including the plant pathogen Ustilago maydis[5] and the cheesemaker's fungus Geotrichum candidum also have dimorphic life cycles.
Mnemonics
In medical mycology, these memory aids help students remember that among human pathogens, dimorphism largely reflects temperature:
- Mold in the Cold, Yeast in the Heat (Beast)
- Body Heat Probably (Changes) Shape
- Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis, (Coccidioides immitis) is in parentheses because it changes to a spherule of endospores, not yeast, in the heat), Sporothrix schenckii.
- This phrase says "Probably" because there is always an exception (in this case fungi like Candida albicans) which change in the opposite direction: to mold in the heat!
References
- "Fungi". Archived from the original on June 6, 2009. Retrieved 2009-06-06.
- Gauthier, GM (May 2017). "Fungal Dimorphism and Virulence: Molecular Mechanisms for Temperature Adaptation, Immune Evasion, and In Vivo Survival". Mediators Inflamm. 2017: 8619307. doi:10.1155/2017/8619307. PMC 5463159. PMID 28626346.
- Chandler JM, Treece ER, Trenary HR, et al. (2008). "Protein profiling of the dimorphic, pathogenic fungus, Penicillium marneffei". Proteome Sci. 6 (1): 17. doi:10.1186/1477-5956-6-17. PMC 2478645. PMID 18533041.
- "Dimorphic Fungi". Retrieved 2007-08-19.
- Sánchez-martínez, Cristina; Pérez-martín, José (2001). "Dimorphism in fungal pathogens: Candida albicans and Ustilago maydis—similar inputs, different outputs". Current Opinion in Microbiology. 4 (2): 214–221. doi:10.1016/S1369-5274(00)00191-0. PMID 11282479.
- Kenyon, Chris; Bonorchis, Kim; Corcoran, Craig; Meintjes, Graeme; Locketz, Michael; Lehloenya, Rannakoe; Vismer, Hester F.; Naicker, Preneshni; Prozesky, Hans; van Wyk, Marelize; Bamford, Colleen; du Plooy, Moira; Imrie, Gail; Dlamini, Sipho; Borman, Andrew M.; Colebunders, Robert; Yansouni, Cedric P.; Mendelson, Marc; Govender, Nelesh P. (2013). "A Dimorphic Fungus Causing Disseminated Infection in South Africa". New England Journal of Medicine. 369 (15): 1416–1424. doi:10.1056/NEJMoa1215460. ISSN 0028-4793. PMID 24106934.