LG 3.11 MCB - Fungal and Parasitic Infections of the CNS

Question 1

What is the shape of Cryptococcus? What are the two types (differentiate between which cause virulence in immunocompromised/immunocompetent, location, what found in)?

Answer 1

Oval budding yeast.

Cryptococcus neoformans: birds, world-wide, immunocompromised.

Cryptococcus gatii: eucalyptus trees, PNW/Aus, immunocompetent.

Question 2

What is the normal cycle of transmission of Cryptococcus?

Answer 2

Budding yeast -> sporulation.

We inhale spores -> lungs -> can disseminate to brain.

Question 3

What are the virulence factors of Cryptococcus? How does it get around in our body to cause encephalitis or meningitis?

Answer 3

Polysaccharide capsule = anti-phagocytic.

Melanin = resists oxidative killing.

Hops a ride with macrophages (trojan horse).

Question 4

Name 5 ways to diagnose cryptococcus.

Answer 4

Latex agglutination.

Lateral flow assay.

India ink stain.

MRI/CT for lesions.

Sabouraud dextrose agar.

Question 5

What is the treatment for Cryptococcus? (what 2 things does this treatment affect?).

Answer 5

Antifungals.

Knocks out transcription/ cell wall synthesis.