L61 Flashcards Preview

HDID Block 2 > L61 > Flashcards

Flashcards in L61 Deck (19):
1

What 2 bugs cause mucormycosis?

Mucor
Rhizopus

2

What infections are the result of mucormycosis?

Rhinocerebral zygomycosis
Pulmonary

3

Walk through the pathogenesis of rhinocerebral zygomycosis

Inhale mucor/rhizopus spores
1st infection @ sinuses
Invade BVs --> necrosis
Invade eye
Direction access to brain

4

Describe the shape of fungi for mucormycosis

Broad
No septa
Branch at right angles

5

What is the clinical presentation of mucormycosis

Sinus symptoms + necrotic lesions
- Ethmoid sinus involvement
Pulmonary = pulmonary mucormycosis

6

What are you look for on CT and histo for pulmonary mucormycosis

Histo = coag necrosis
CT = dense infarction w/ halo

7

Treat mucormycosis

Amphoterin B
Surgical debridement of necrotic areas

8

What bug causes cryptococcosis

Cryptococcus neoformans

9

What are the 3 symptoms of a cryptococcal opportunistic infection?

Pna
Meningitis
Fever

10

Specifically, which IC pts are at highest risk for a cryptococcal infection?

T cell compromised
- On steroids
- Transplant
- HIV

11

Explain cryptococcal pathogenesis

Inhale yeast
Replicate in lung
Progressive infection b/c IC
Spread and cross BBB
Further replication in gelatinous lesion

12

What is a characteristic VF for cryptococcal neoformans

HUGE capsule - doesn't stain well for this reason
Glucuronoxylomannan
X phagocytosis

13

What stains do you use for cryptococcus? How do they look on stain?

PAS
GMS
Mucicarmine silver
INDIA INK
- Stain LIGHT
- Huge halo around nucleus b/c of capsule

14

Which enzyme helps with melanin production for cryptococcus?

Phenoloxidase
Make melanin b/c inhibits O2 killing by host

15

Treat cryptococcus

Start: amphotericin B + 5 FC
(Just to get infection under control b/c nephrotoxic)
Continue: fluconazole

16

What bug causes pneumocytosis?

Pneumocystis carinii/jirovecii

17

Pneumocytosis presentation

Pna: fever, dyspnea, hypoxia, non-productive cough

18

What do you see on histo and radiology for pneumocystis pna?

Diffuse infiltrates on CXR
Histo: occluded capillaries

19

Treat pneumocystis pna

TMP/SMX