L33 - Introduction To Mycology

Question 1

What are general characteristics of fungi?

Answer 1

• rigid cell wall
• ergosterol in cell membrane
• reproduction by spores
• lack of susceptibility to antibacterial antibiotics

Question 2

What are fungi important for?

Answer 2

• ecology
• commerciail
• pharmaceutical
• pathogens

Question 3

What are fungi?

Answer 3

• eukaryotic
• unicellular (yeasts) or multicellular

Question 4

What are the 3 types of fungi?

Answer 4

• yeasts // candida albicans
• multicellular filamentous moulds // trichrophyton
• macroscopic filamentous fungi

Question 5

What are the organelles in fungal cell?

Answer 5

• mitochondria
• ER
• golgi apparatus
• membrane
• cell wall

Question 6

What are the parts of fungal cell wall?

Answer 6

• mannan
• B-glucan
• chitin
• membrane
• • ergosterol

Question 7

What are yeast like?

Answer 7

• single cells, reproduce by budding or fission
• can form spores

Question 8

What are mould like?

Answer 8

• grow as masses of overlapping and interlinking hyphal filaments (mycelium)
• reproduce by formation of spores

Question 9

What are dimorphic fungi?

Answer 9

Can switch between yeast and hyphal forms

Question 10

What are mycelium?

Answer 10

• hypha collectively form it
• can be septate or nonspeptate
• grows at the tips

Question 11

What are septate hypha like?

Answer 11

The cytoplasm is connected by large spores in the septa

Question 12

What do dimorphic fungi usually form?

Answer 12

• at environmental temperatures
• grow as yeast cells in the body
• conversion triggered by temperature

Question 13

What do candida do?

Answer 13

Reverse - form hypha within the body

Question 14

What are the categories of mycoses?

Answer 14

• superficial and cutaneous
• subcutaneous
• systemic/deep

Question 15

What are superficial and cutaneous mycoses?

Answer 15

Fungus grows on body surface

Question 16

What are subcutaneous mycoses?

Answer 16

• deeper layers of skin invovled
• without dissemination distant sites

Question 17

What are systemic/deep mycoses?

Answer 17

• Infection mainly through lungs
• may become widely disseminated and involve any organ system

Question 18

What are examples of pathogenic fungi?

Answer 18

• trichophyton
• candida albicans

Question 19

What is the type, category and disease from trichophyton?

Answer 19

• mould
• cutaneous
• dermatophytosis (athlete’s foot, ringowm, onychomycosis)

Question 20

What is the type, category and disease from candida albicans?

Answer 20

• dimorphic
• superficial - systemic
• oral or vaginal thrush, nail/skin infection, sepsis

Question 21

What are dermatophytes infections like?

Answer 21

• infection spreads out as circle, healing skin in middle
• cause tinea infections
• infection direct contact or indirect
• evolved dependency on human/animal infection

Question 22

What are treatment of fungal infections?

Answer 22

• not bacterial antibiotics
• many antifungals act on the membrane lipid ergosterol
• others act on DNA/RNA synthesis or microtubules

Question 23

How do antifungals on ergosterol?

Answer 23

• inhibition of synthesis - accumulation of toxic sterol intermediates
• direct binding = leaky cells

Question 24

What do treatments of fungal infections target?

Answer 24

• membrane
• cell wall
• tubulin
• DNA/RNA