Laboratory Practical Flashcards
Purpose of KOH preparation
A 10% potassium hydroxide (KOH) preparation is used when specimens such as hair, nails, skin or tissue are to be examined for fungal elements.
KOH digests the host cellular material allowing the fungal elements to be more easily seen.
Purpose of India Ink Procedure
When combined with pelleted material from cerebrospinal fluid, India ink allows visualization of the polysaccharide capsules of the yeast, Cryptococcus neoformans.
Purpose of lactophenol stain for a fungal wet mount
Used to enhance the hyphial and reproductive structures of molds.
Sabouraud Dextrose Media
Supports most saprophytic fungi and pathogenic molds, non-inhibitory. 2% glucose with a neutral pH.
Inhibitory mold agar
Inhibits most bacterial growth, the antibiotics typically included are chloramphenicol and possibly gentamicin, penicillin, ciprofloxacin, and streptomycin.
Brain heart infusion agar
And enriched media made from infusions of calf brain and beef heart, usually used for recovery of dimorphic molds, this media may have sheep blood added; antibacterial additives are also available.
Mycocel/Mycobiotic Agar
Contains cycloheximide and chloramphenicol to inhibit most saprophytic molds, can also inhibit Candida, Cryptococcus, zygomycetes and other potentially significant molds useful for Dermatophyte recovery
Chromagar Candida
Uses variations of vitamin content to differentiate mixed yeast cultures
Media for sporulation
Corn meal with tween 80, Trypan blue or dextrose, potato dextrose, potato flake, brain heart infusion with sheep blood, water agar, Hay agar, oatmeal agar, V-8 agar, and carnation leaf agar
Biochemical media
Germ tube, trichophyton agar, API strips, birdseed agar, urea, nitrate agar
Hyaline hyphae
Clear, transparent, or lightly pigmented
Dematiaceous Hyphae
Dark hyphae and conidia that may appear black or brown due to melanotic pigment the cell wall
Septate
Having cross walls in hyphae, conidia or spores without pinching
Non-septate hyphae
Hyphae that or a continuous tube without breaks
Description of mold texture
Cottony, folded, velvety, granular, smooth, waxy, creamy
Arthrospore/Arthroconidia
An asexual spore formed by the breaking up of hyphae at the point of septation, the resulting cell maybe rectangular or barrel shaped with thick or thin walls
Blastospore
A conidium formed by budding along a hyphae, pseudohyphae, or a single mother yeast cell
Sporangiospores
And asexual spore formed by the cleavage of sporangium contents these are seen in the zygomycetes
Dermatophyte
Produce microconidia and macroconidia
Microconidia
Small usually single cell conidia, the smaller of the two cells in fungi that produce both large and small conidia, usually round, pear-shaped, club shaped or ovoid
Macroconidia
Large usually segmented into two or more cells, they result from the conversion of an entire hyphal element into a multi celled conidia which can be thick or thin walled, smooth or rough, club or oval-shaped, single or in clusters
Chlamydiaconidia
Comparable to bacterial spores
