Fungi Flashcards
General Characteristics of Fungi
Eukaryotic
Macroform: mushrooms, puffballs, gill fungi
Microform: mold, yeast
Saprobes (live on dead or decaying organic matter)
Yeasts
Unicellular
Round/oval shaped with possible pseudohyphae
Asexual reproduction
Moulds
Multicellular
filamentous/tubular hyphae
Sexual or asexual reproduction
Mycelium
intertwined mats of hyphae
- Vegetative: attached/penetrates to obtain substrate
- Reproductive: Aerial structures or spores (asexual)
Dimorphic Fungi
Same organism can exist in mold or yeast form
Most fungi are dimorphic (except Aspergillus (mold) & Torula (yeast))
Mold form: free-living state
Yeast form: Parasitic state
KOH Procedure
Scraping from margin
2-3 drops 10% KOH in water
1 drop lactophenol cotton blue (optional)
examine under high dry magnification
Fungal cell wall
Thick, Rigid
no peptidoglycans but chitin and additional polysacc (beta-glucan and mannan)
No Capsule except Cryptococcus neofomans
Fungal cytoplasmic membrane
phospholipid bilayer containing ERGOSTEROL (not cholesterol)
ZYGOMYCOTINA
Most primitive, Filamentous, Non-septate
Reproduce sexually & asexually
–Asexual spores
•NOT PRIMARY PATHOGENS (OPPORTUNISTIC)
ASCOMYCOTINA
Septate
•Produce sexual & asexual spores
–Asexual spores (conidia)
–Sexual spores (ascospores)
•MEMBERS include:
–Yeasts & moulds
–Dermatophytes (skin infections)
BASIDOMYCOTINA
•Septate •Produce sexual spores (basidiospores) •MEMBERS include: –Mushrooms & Puffballs –Filobasidiella neoformans
DEUTEROMYCOTINA
- Septate
- Reproduce asexually
- Sexual reproductive structures UNKNOWN
Mycoses / Mycosis
Fungal infections
Systemic: inhalation, disseminates
Subcutaneous: by wound or puncture, remain localized
Cutaneous: invade keratinized and cutaneous tissue
Superficial: infections of skin and hair. can reappear
Opportunistic: immuno-compromised patients
Mycotoxins: amantia and aflatoxin
