Mycology

By completing this question set, you will apply fungal cell biology to explain why antibacterial agents are ineffective against fungi and why standard antifungals exploit ergosterol, β-1,3-glucan, and the dimorphic growth switch. You will distinguish organisms by morphology — the branching angle and septation of hyphae (Aspergillus 45° septate vs. Mucormycetes 90° aseptate) and the characteristic budding patterns of yeasts (Candida pseudohyphae with germ tube, Cryptococcus encapsulated, Blastomyces broad-based, Paracoccidioides mariner's wheel). You will apply the immune status framework to predict clinical infection: IL-17 deficiency → mucocutaneous candidiasis; neutropenia → invasive Aspergillus or IPA; CD4 <200 → PCP; CD4 <100 → Cryptococcus and disseminated histoplasma; DKA → rhinocerebral mucormycosis. You will identify each dimorphic endemic fungus from geographic exposure and clinical presentation, explain why Coccidioides uniquely forms spherules rather than yeast at body temperature, and explain why coccidioidal meningitis CSF shows eosinophils while other fungal meningitides do not. You will explain why India ink visualizes the Cryptococcus capsule and why PCP requires TMP-SMX rather than standard antifungals.