Flashcards in Mycology Deck (19):
What are the main features of fungi?
-uni or multicellular
-mostly reproduce asexually (mitosis)
-monomorphic, dimorphic or polymorphic
What are the main components of fungi exteriors?
-rigid cell wall: chitin, glucans, mannoproteins
-cytoplasmic membrane: phospholipid bilayer w ergosterol
What are the 3 major classes of fungi?
-dimorphic fungi (yeast and mould--> depends on temp, nutrietns, CO2)
What are the roles of aerial and vegetative hyphae in moulds (mycelium)?
aerial hyphae: support for reproductive structures
vegetative hyphae: provides nutrients to aerial hyphae
For dimorphic fungi, when are they seen in yeast form versus mould form?
(Hint: Temperature differential)
yeast form: in vivo or 37deg c.
mould form; 22-25 deg c.
List dimorphic fungi examples:
-Blastomyces dermatitidis *
-Histoplasma capsulatum *
*endemic in Canada
What immune reactions are critical in eliminating fungi?
-nonspecific inflammatory reactions...esp neutrophil phagocytosis and killing.
Who is at increased risk of fungal infection that does not clear?
1. Patients with depressed neutrophil function/number:
-disorders of neutrophil funx: chronic granulomatous disease
2. Patients with depressed CMI (cell-mediated immunity):
What are the 4 classifications of fungal infections (location):
What is the most common mucocutaneous fungal infection?
What are the favourable conditions for these?
1. C. albicans
2. -moisture + warmth
-disruption of normal flora (ABs)
-diminished neutrophil phagocytosis and killing
-diminished cell-mediated immunity
What type of fungi typically cause superficial fungal infections?
ex. Ringworm or Tinea (refers to serpentine lesion)
What do dermatophytoses use as nutrient source?
What enzyme do they use to do so?
What are the 3 main epidemiological groups of superficial fungi?
1. Geophilic (soil) ex. Microsporum gypseum
2. Zoophilic (parasitic on animals) ex. Microsporum canis
3. Anthropophilic (humans) ex. Trichosporon rubrum
What are the 3 main genera of dermatophytes?
Name a common superficial fungal infection:
What is it caused by?
-Tinea versicolor (Pityriasis versicolor)
caused by Malassezia furfur
What are the 2 common classes of subcutaneous mycetoma?
What population does it effect most often?
1. Chromoblastomycosis (caused by 'black moulds' in soil)
2. Mycetoma (caused by black moulds and fungus-like bacteria)
-effects barefooted populations in Tropics
List systemic fungal infections:
-Blastomyces dermatitidis (Blastomycosis)- Ontario + Manitoba
-Coccidioides immitis (Coccidioidomycosis)
-Histoplasma capsulatum (Histoplasmosis)
-Paracoccidioides brasiliensis (Paracoccidioimycosis)
List the characteristics of dimorphic fungi:
-produce asymptomatic to severe life threatening disseminated disease
- primary lung infx +/- dissemination
-infect normal and immunocompromised hosts