Mycology (study of fungi)

Question 1

Where are fungi widespread in?

Answer 1

Environment

Question 2

Does it have chlorophyll?

Answer 2

No

Question 3

What does it need to survive?

Answer 3

Absolute need for complex nutrients

Question 4

What are the 2 basic forms of fungi?

Answer 4

1. Yeasts - single cell
2. Hyphae - filamentous form
   Some have both - dimorphic

Question 5

What culture do they grow on?

Answer 5

Sabouraud Dextrose Agar
Selective supplements: cycloheximide, chloramphenicol -> inhibit unwanted bacteria

almost all medically important fungi grow in culture

yeast (single colony), mould (spread out)

Question 6

What does Aspergilus spp. show on culture?

Answer 6

Hyphal growth (mould)
Fluffy colonies

Question 7

What does Candida spp. show on culture?

Answer 7

Yeast cells
Discrete colonies

Question 8

How to identify filamentous fungi?

Answer 8

Observing culture appearance and characteristic microscopical structures

Question 9

Identifying feature of Candida albicans?

Answer 9

Germ tube positive (other Candida species are negative)

Question 10

Identifying feature of Cryptococcus neoformans

Answer 10

Capsulated (only yeast that is capsulated)

Question 11

What other diagnostic methods?

Answer 11

1. Carbohydrate assimilation tests (growth with single source of carbon)
2. Mass spectroscopy
3. Antigen tests
4. Molecular techniques (increasingly used PCR, sequence genome match with library)

Question 12

What are the diseases caused by fungi?

Answer 12

1. Poisoning
   - Acute or chronic
   - Aflatoxins (liver cancer)
2. Allergy
   - Chronic sinusitis
3. Infections

Question 13

What are the 3 clinical classification of fungal infections?

Answer 13

1. Superficial
2. Subcutaneous
3. Systemic

Question 14

What are some dimorphic fungi?

Answer 14

Candida albicans
Spororthrix schenckii
Pneumocystis jirovecii
Talaromyces marneffei

Question 15

What are the 2 routes of spread of fungi to respiratory tract?

Answer 15

1. Endobronchial
2. Hematogenous