Microbiology 16 - Fungal infections Flashcards Preview

Year 5 Pathology ICSM > Microbiology 16 - Fungal infections > Flashcards

Flashcards in Microbiology 16 - Fungal infections Deck (30)
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1

What is the main conponent of fungal cell walls?

Chitin

2

What is the main component of fungal cell membranes?

Ergosterol

3

What is the reproductive method of yeats?

Budding

4

Recall 3 examples of yeasts that are clinically important

Candida
Cryptococcus
Histoplasma

5

What are moulds?

Multicellular hyphae

6

Give 2 examples of moulds that are clinically important

Dermatophytes
Aspergillus

7

Recall the empiric treatment for oral, vulvovaginal and cutaneous candida infection

Oral: nystatin
Vulvovaginal and cutaneous: co-trimoxazole, but if oral treatment is needed then use fluconazole

8

Recall the principles of candidaemia management

1. Look for source and signs of dissemination:
- Imaging
- Serology for B-D-glucan
- echo/fundoscopy
2. Antifungals for at least 2/52 from date of first negative blood culture - repeat BCs every 48 hours

9

Recall the different types of cryptococcus, and which of these infect immunocompetent vs immunocompromised hosts

Serotypes A and D = cryptococcus neoformans (immunocompromised hosts)

Serotypes B and C = cryptococcus gatti (immunocompetent hosts)

10

Which type of cryptococcus can cause meningitis?

Cryptococcus gatti

11

What ink can be used to stain for cryptococcus?

India Ink

12

How should cryptococcus infection be managed?

1. Induction: 2/52 of amphotericin B + flucytosine
2. Consolidation: 8/52 of high dose fluconazole
3. Maintenance: 1 year low-dose fluconazole

13

Which type of aspergillus disease is an allergic disease?

ABPA

14

How does aspergillus appear under the microscope?

Fluffy colonies

15

What parts of the body can be infected by aspergillus?

Pre-formed cavities (eg. by TB) - so treated pulmonary TB may be in the history

16

What is a galactomannan assay used for?

Aspergillosis diagnosis

17

Why is pneumocystis jirovecii an unusual fungus?

No ergosterol wall

18

What is the typical history for PCP pneumonia?

Desaturating on exertion

19

What are the clinical features of mycormycoses?

Orbital/facial cellulitis with discharge of black pus from nose/ palate

20

How are mycormycoses managed?

LONG duration of ambisone (amphotericin B)

21

Recall an example of a dermatophyte

tinea

22

Where does tinea cruris infect?

Groin

23

How is tinea diagnosed?

Often clinically, but can be confirmed via skin scrapings for MC&S

24

Recall 4 classes of antifungal

Azoles
Polyenes
Echinocandins
Pyrimidine analogues

25

Recall the side effect profile of each class of antifungal

Azoles - abnormal LFTs
PolyeNes - Nephrotoxicity
Echinocandins - relatively innocuous
Pyrimidine analogues - blood disorders

26

What is the mechanism of action of azoles?

Inhibit ergosterol synthesis

27

What is the mechanism of action of polyenes?

Bind sterols in membranes to create leakage of electrolytes

28

Give 2 examples of polyene medications

Amphotericin B
Nystatin

29

Which 2 types of fungus are echinocandins particularly useful for?

Candida
Aspergillus

30

What class of antifungal is flucytosine?

Pyrimidine analogue

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