Fungi & Disease

Question 1

Are fungi eukaryotic or prokaryotic

Answer 1

Eukaryotic - contain nucleus

Question 2

What do fungi feed on and what is the name of this type of organism

Answer 2

• Absorb nutrients from environment
• Decaying matter
• Like moisture & sugar (starches)

This is called being a Saprophytic Chemoheterotroph

Question 3

Morphology of yeast

Answer 3

Single celled

Question 4

Morphology of mould

Answer 4

Filamentous
Grow in hyphae which may contain multiple nuclei

Question 5

Structures within the fungal cell

Answer 5

• Ribosomes
• Golgi
• ER
• Nucleolus
• Nucleus
• Smooth ER
• Vacuole
• Cell wall NB
• Cell membrane
• Mitochondrion
• Lysosome
• Cytoplasm

Question 6

How does budding occur in yeast

Answer 6

• Normal parent cell
• Nuclear division occurs and a bud develops
• Two daughter nuclei are formed
• A septum forms between bud and a new yeast cell is formed

Question 7

What is the fungal cell wall made of

Answer 7

• Beta glucans
• Chitin (polymer of NAG)

Question 8

What is the cell membrane made of

Answer 8

Ergosterol
(it’s still a phospholipid bilayer though)

Question 9

What is another name for fungal disease/infections

Answer 9

Mycoses

Question 10

Ringworm can cause what?

Answer 10

• Athletes foot
• Jock itch
• Onychomycosis (white/yellow streaks on nails, crumbly nails that may lift)

Question 11

fungI that cause ringworm (3)

Answer 11

1. Trichophyton
2. Microsporum
3. Epidermophyton

Question 12

What parts of the body do ringworm causing fungi affect

Answer 12

• Skin
• Hair
• Nails

Question 13

Sources of dermatophytes (ringworm)

Answer 13

• Mainly human
• Environment
• Animal contact - cats & dogs

Question 14

What type of mycosis is sporotrichosis

Answer 14

Subcutaneous mycosis

Question 15

What fungus causes sporotrichosis

Answer 15

Sporothrix schenkii

Question 16

Where is sporothrix schenkii found and how does it enter the skin

Answer 16

• Bark of trees
• Shrubs & plants
• Plant debris in soil

Enters body through breaks in the skin (e.g: thorn prick)

Question 17

How does sporothrix schenkii spread in the body

Answer 17

It spreads along the lymphatics

Question 18

WHat does Candidiasis being opportunistic mean

Answer 18

It causes disease when it gains dominance
(When antibiotics disturb normal flora or in immunocompromised)

Question 19

The 3 forms of candidiasis

Answer 19

1. Oral Candidiasis - Thrush
2. Cutaneous Candidiasis - Nappy rash
3. Female Genital Candidiasis - Vaginal Thrush

Question 20

What kind of fungus is Cryptococcus neoformans

Answer 20

Yeast

Question 21

What is Cryptococcus neoformans found in

Answer 21

Pigeon droppings

Question 22

Where does Cryptococcus neoformans affect in the body

Answer 22

Infection via respiratory tract

Question 23

What does Cryptococcus neoformans usually present as

Answer 23

Meningitis especially in immunocompromised (Tcell deficient NB - HIV)

Question 24

What kind of fungus is Aspergillus fumigatus

Answer 24

Opportunistic, spore forming mould

Question 25

How does an Aspergillus fumigatus infection occur

Answer 25

• Usually by inhalation of spores
• Can infect wounds/burns

Question 26

What is Aspergilloma

Answer 26

A fungus ball that colonizes in a healed lung scar or abcess from a previous disease