Basic Concepts Flashcards
the taxonomy of fungi are based on
sexual stage, hyphae and spores
perfect reproduction refers to
sexual reproduction - are products of the sexual cycle
imperfect reproduction refers to
asexual reproduction - the asexual spores are produced via mitosis and cell division
how can we differentiate fungi from bacteria
cell wall composition, response to antibiotics, nuclear material arrangement, size, has true nuclei, the presence or absence of mitochondria and ER
the plasma membrane and cell wall of fungi are made of
ergosterol and chitin, respectively
how do fungi metabolize
they obtain their carbon compounds via absorption of nutrients through their cell wall. small molecules diffuse through the cell wall while macromolecules + insoluble polymers undergo prelim digestion by enzymes released
what is unique about the hyphae and septum structure
nuclei can move freely between the septum - intercellular migration of nuclei
aerial hyphae and vegetative mycelium
aerial hyphae grow above surface of the agar, giving mold colony color, texture and used for reproduction. vegetative mycelium is used for nutrition
mycelial growth
mycelial growth typically involves the growth of hyphae at the tips
mycelial fungal reproduction
the reprodcutive structures of the fungi are its spores, which each can create its own colony
blastic conidiogenesis and an example
an example of blastic conidiogenesis- Penicillum
thallic conidiogenesis and an example
an example of thallic conidiogenesis - Trichphyton and Coccidiodes immitis
yeast tend to reproduce
asexually by budding
best ways our bodies prevent fungal growth
intact skin, endogenous long chain unsaturated fatty acids, dryness, epithelial turnover rate, lined body surfaces, pH competing with the normal bacterial flora
the three general clinical presentations of fungal infections
cutaneous, subcutaneous, opportunistic infections and systemic mycoses, and can produce disease by eliciting an immune response
the diagnosis of fungal infections is based on
microscopy, culture, use of stains to enhance visualization, biopsy, radiographs
Wood’s lamp/ uv light
best used for the detection of hair, skin, nails infections in certain dermatophytes
the examination of specimens
specimens are examined macroscopically and microscopically, checking for bloody, purulent and necrotic areas
KOH prep and how its used
KOH prep is important for detecting fungal elements from cellular material, KOH dissolves cellular material allowing for detection of hyphae an etc
Parker’s blue black and KOH prep
parker’s blue black is added to the KOH, it binds to the KOH and enhances visualization
India ink Prep
useful for the visualization of yeasts with capsules, used to detect the presence of Cryptococcus neoformans
Calcoflour white stain
used for the direct examination of most fungal specimens using fluorescent microscopy
gram stain
the gram stain is used for the identification of very few stains, a poor stain to use with clinical specimens for fungi
