An introduction to Fungi

Question 1

Mycology

Answer 1

The study of fungi

Question 2

Give a brief summary of what a fungus is

Answer 2

A eukaryote which lacks chlorophyll with ergosterol being the main sterol

Question 3

Can fungi form spores?

Answer 3

Yes

Question 4

Give 3 examples of fungus

Answer 4

Mould, yeast and mushrooms

Question 5

Basidomycetes

Answer 5

Sexual spores are basidospores and have a long tube with basdia underneath the mushroom cup
Examples are mushroom and moulds

Question 6

Ascomycetes

Answer 6

Ascospores contained in a sac

Mould and yeast

Question 7

Zygomycetes

Answer 7

Rough walled zygote containing one or more zygospores

Moulds only

Question 8

Dermatophytes

Answer 8

Use keratin as a nutrient source to create ringworm infection eg pityriasis vesicolor - yeast which forms hyphae in skin

Question 9

Give 2 examples of how host factors can contribute to pathogenicity

Answer 9

• Warm, moist area eg skin and mucous membranes

- Antibacterial agents will reduce competition

Question 10

2 Examples of iatrogenic immunosuppression

Answer 10

Chemotherapy and steroids

Question 11

2 Examples of disease processes immunosuppression

Answer 11

AIDs and Leukaemia

Question 12

Candida

Answer 12

Found in GI tract
Get into blood and cause infection eg oral, vaginal, oesophageal and nail
Especially in seriously immunocompromised hosts

Question 13

Aspergillosis

Answer 13

Moulds ubiquitous due to inhalation if canidia and are strongly angiovasive

Question 14

4 Examples of medical mycology

Answer 14

• High res CT/ histopathology
• Fungal antigen/antibody
• PCR for fungal DNA
• Culture from usual sterile sight

Question 15

3 Antifungals

Answer 15

Azoles, echinocandis and polyenes

Question 16

Azoles

Answer 16

Target ergosterol formation

Question 17

Echinocandis

Answer 17

Target wall and are fungicidal

Question 18

Polyenes

Answer 18

Target membrane and are the gold standard which bind ergosterol and puncture membrane