L33 - Introduction To Mycology Flashcards
What are general characteristics of fungi?
- rigid cell wall
- ergosterol in cell membrane
- reproduction by spores
- lack of susceptibility to antibacterial antibiotics
What are fungi important for?
- ecology
- commerciail
- pharmaceutical
- pathogens
What are fungi?
- eukaryotic
- unicellular (yeasts) or multicellular
What are the 3 types of fungi?
- yeasts // candida albicans
- multicellular filamentous moulds // trichrophyton
- macroscopic filamentous fungi
What are the organelles in fungal cell?
- mitochondria
- ER
- golgi apparatus
- membrane
- cell wall
What are the parts of fungal cell wall?
- mannan
- B-glucan
- chitin
- membrane
- ergosterol
What are yeast like?
- single cells, reproduce by budding or fission
- can form spores
What are mould like?
- grow as masses of overlapping and interlinking hyphal filaments (mycelium)
- reproduce by formation of spores
What are dimorphic fungi?
Can switch between yeast and hyphal forms
What are mycelium?
- hypha collectively form it
- can be septate or nonspeptate
- grows at the tips
What are septate hypha like?
The cytoplasm is connected by large spores in the septa
What do dimorphic fungi usually form?
- at environmental temperatures
- grow as yeast cells in the body
- conversion triggered by temperature
What do candida do?
Reverse - form hypha within the body
What are the categories of mycoses?
- superficial and cutaneous
- subcutaneous
- systemic/deep
What are superficial and cutaneous mycoses?
Fungus grows on body surface
What are subcutaneous mycoses?
- deeper layers of skin invovled
- without dissemination distant sites
What are systemic/deep mycoses?
- Infection mainly through lungs
- may become widely disseminated and involve any organ system
What are examples of pathogenic fungi?
- trichophyton
- candida albicans
What is the type, category and disease from trichophyton?
- mould
- cutaneous
- dermatophytosis (athlete’s foot, ringowm, onychomycosis)
What is the type, category and disease from candida albicans?
- dimorphic
- superficial - systemic
- oral or vaginal thrush, nail/skin infection, sepsis
What are dermatophytes infections like?
- infection spreads out as circle, healing skin in middle
- cause tinea infections
- infection direct contact or indirect
- evolved dependency on human/animal infection
What are treatment of fungal infections?
- not bacterial antibiotics
- many antifungals act on the membrane lipid ergosterol
- others act on DNA/RNA synthesis or microtubules
How do antifungals on ergosterol?
- inhibition of synthesis - accumulation of toxic sterol intermediates
- direct binding = leaky cells
What do treatments of fungal infections target?
- membrane
- cell wall
- tubulin
- DNA/RNA
