**Question:** True about Cryptococcus neoformans is all EXCEPT

A. It primarily infects immunocompromised patients.
B. It causes meningitis and disseminated infections.
C. Cryptococcus neoformans is an obligate intracellular parasite.
D. It is a common cause of pneumonia in children.

**Correct Answer:** C. Cryptococcus neoformans is an obligate intracellular parasite.

**Core Concept:** Cryptococcus neoformans is a pathogenic yeast that primarily affects immunocompromised patients, particularly those with acquired immunodeficiency syndrome (AIDS) and those receiving immunosuppressive therapy. The organism can cause meningitis, as well as disseminated infections, including pneumonia, osteomyelitis, and endocarditis. Cryptococcus neoformans belongs to the family Cryptococcaceae and is an encapsulated, dimorphic fungus that can switch between yeast and mold forms.

**Why the Correct Answer is Right:** Cryptococcus neoformans is known as an extracellular parasite, meaning it primarily infects host cells by binding to cell surface receptors and entering the host cells via phagocytosis. Once inside the host cell, it resides within the cell and multiplies, leading to tissue damage and inflammation. However, being an obligate intracellular parasite implies that the fungus is unable to survive or multiply outside host cells. Therefore, the correct answer (C) is incorrect because Cryptococcus neoformans is not an obligate intracellular parasite.

**Why Each Wrong Option is Incorrect:**

A. Immunocompromised patients are more susceptible to cryptococcal infections. However, it is not specific to Cryptococcus neoformans being an obligate intracellular parasite.

B. Cryptococcus neoformans causes meningitis and disseminated infections, which are accurate consequences of the infection. However, this option does not address the obligate intracellular nature of the organism.

D. Cryptococcus neoformans causing pneumonia in children is false, as it primarily affects immunocompromised patients. However, this option does not address the obligate intracellular nature of the organism.

**Clinical Pearl:** Obligate intracellular parasites rely on host cells for survival and reproduction. In the case of Cryptococcus neoformans, the host immune response against the fungus leads to phagocytosis and entry into the host cell, where it can multiply without causing harm to the host cell. This understanding is crucial for diagnosing and treating cryptococcal infections, as it helps in identifying the appropriate antifungal agents, such as amphotericin B and flucytosine, which target the fungal cell wall and nucleic acids, respectively, to treat the infection effectively.