Introduction to Fungi Flashcards
What is fungi
A chemo-organotrophic eukaryote which lacks chlorophyll and forms spores
What is the structure of fungi
Cell wall which contains polysaccharides (e.g. chitin or glucan) and absorbs nutrients
Membrane that contains ergosterol as major sterol
How are fungi classified
Principally based on morphology
What are the three groups that the fungal kingdom can be split into
Basidiomyceyes
Ascomycetes
Zygomycetes
What are yeasts
Fungi that favour a unicellular habit
Give an example of a dermatophytic fungal infection
Ringworm caused by tinea capitis, tinea facei, tinea barbae, tinea corporis. depending on the location on the body.
What is dermatophytosis
Moulds with a predilection to degrade keratin as a nutrient source
What host factors can contribute to the pathogenicity of fungal infections
Presence of a favourable micro-environment (warm, moist areas) will encourage the growth of fungi on skin and mucous membranes
Broad-spectrum antibacterial agents will reduce competition for epithelial colonization sites in the gut
Immunosuppression of all types (latrogenic e.g. steroids, chemo or disease processes e.g. AIDS, leukaemia) may create a window of opportunity for fungal invasion
Who can chronic mucocutaneous Candida infection affect
In individuals with an unusual combination of endocrine and immune dysfunction
How can fungi be detected
Direct detection using histopathology or high-res CT scans
Direct smear
Detection of the circulating fungal antigens
Detection of circulating antibodies to fungi
PCR for fungal DNA
Culture of fungus from normally sterile site
How do antifungals work
By causing membrane or cell wall stress
What are the problemss with antifungal treatment
Spectrum of activity Static or cidal IV vs oral Toxicity Cost
