The following fungi are thermally dimorphic, except:
**Core Concept**
Thermally dimorphic fungi are a group of fungi that change their growth form in response to temperature. At room temperature (25°C), they grow as molds, but at body temperature (37°C), they convert into yeast. This characteristic is crucial for their pathogenicity, as they can survive and thrive in the human body.
**Why the Correct Answer is Right**
The correct answer is a fungus that does not exhibit thermal dimorphism. Thermal dimorphism is a unique property of certain fungi, such as *Histoplasma capsulatum*, *Blastomyces dermatitidis*, and *Coccidioides immitis*. These fungi change their morphology in response to temperature, which allows them to adapt to the human body's environment. However, some fungi do not exhibit this characteristic, and the correct answer is one such example.
**Why Each Wrong Option is Incorrect**
* **Option A:** *Histoplasma capsulatum*, which is known for its thermal dimorphism, changes from a mold to a yeast at 37°C.
* **Option B:** *Blastomyces dermatitidis*, another thermally dimorphic fungus, converts from a mold to a yeast at the same temperature.
* **Option C:** *Coccidioides immitis*, which also exhibits thermal dimorphism, changes from a mold to a spherule at 37°C.
**Clinical Pearl / High-Yield Fact**
Thermal dimorphism is a unique characteristic of certain fungi, such as *Histoplasma capsulatum*, *Blastomyces dermatitidis*, and *Coccidioides immitis*, which allows them to cause infections in humans. This property is essential for their pathogenicity and is a key factor in their identification and diagnosis.
**Correct Answer: D. Aspergillus fumigatus**