Introduction to Fungi

Question 1

What is a fungus ?

Answer 1

• This is a eukaryote which lacks chlorophyll and forms spores.
• Its cell wall contains polysaccharides (chitin or glucan)
• Its membrane contains ergosterol as the major sterol
• Classification is based primarily on morphology

Question 2

What is the classification of fungi ?

Answer 2

- Basidiomycetes
	Mainly moulds and mushrooms, a few yeasts
- Ascomycetes
	Moulds and yeasts, some mushrooms
- Zygomycetes 
	Moulds

Question 3

Describe the structure of Basidiomycetes, Ascomycetes and Zygomycetes

Answer 3

Look at the slides

Question 4

Describe the clinically important systemic and dermatophytic fungal infections.

Answer 4

Dermatophytes - these fungi have a predilection to digesting keratin as a nutrient source, and so tend to attack skin and result in ringworm like infections.
E.g. Pityriasis Versicolor – Yeasts that form hyphae in infected skin.

Systemic fungi
Candida is a species of fungi commensal to the GI tract, but one which can cause a lot of problems. They are yeasts and responsible for oral, vaginal, skin, nail oesophageal and many other forms of infections.