LABORATORY EVALUATION (Macroscopic) Flashcards
Media used for the cultivation of asporogenous yeasts
Acetate ascospore agar
This formulation is a better sporulation medium than sodium acetate
potassium acetate
stain used in acetate ascospore agar
Kinyoun carbol-fuchsin acid-fast stain
What species is seen in acetate ascospore agar?
Saccharomyces cerevisiae
Medio used for the isolation of Cryptococcus spp. esp. C. neoformans and C. gattii which is unique in that they produce the enzyme phenol oxidase
Birdseed agar (syn. Niger seed agar)
true/false
Breakdown of substrate (Guizotia abyssinica seed or niger seeds) produces MELANIN which is absorbed into the yeast wall and imparts a tan to brown pigmentation of the colonies
true
reagent used in birdseed agar
chloramphenicol and creatinine
a selective agent that inhibits bacteria and some fungi
chloramphenicol
Enhances melanization of some strains of C. neoformans
creatinine
mediu used for the isolation and differentiation of candida spp.
Bismuth sulfite-glucose-glycine yeast (BiGGY) agar
true/false
Candida spp. reduce the bismuth sulfide (also acts as an inhibitor of bacterial growth) to bismuth sulfite which results in pigmentation
false
Candida spp. reduce the bismuth sulfite (also acts as an inhibitor of bacterial growth) to bismuth sulfide which results in pigmentation
nutritive bases of BiGGY
Peptone
Glucose
Yeast Extract
C. albicans vs C. tropicalis
in terms of color of colonies
C. albicans: Brown to balck colonies with no pigment and no sheen
C. tropicalis: Dark brown colonies with black centers, black pigment diffusion, and sheen
medium used for the cultivation and isolation of all fungi
Brain heart infusion agar (fungal formulation)
true/false
BHI contains 5% sheep red cell
false
10% kase
reagent used in BHI
chloramphenicol
gentamicin
cycloheximide
Inhibits overgrowth of saprophytic fungi
cycloheximide
An adaptation of birdseed agar.
Caffeic agar
what species is detected in caffeic agar?
C. neoformans, brown in color
medium used to distinguish C. neoformans from C. gattii
Canavanine-glycine-bromthymol blue agar
C. gattii vs C. neoformans C. neoformans var. neoformans
in terms of serotypes
C. gattii: serotype B and C
C. neoformans: serotype A
C. neoformans var. Neoformans: Serotype D
C. gattii vs C. neoformans C. neoformans var. neoformans
in terms of colonial color
C. gattii: cobalt blue
C. neoformans and C. neoformans var. Neoformans: greenish yellow
medium used for the isolation of clinically important yeasts
CHROMagar (BD BBL; BD Diagnostics Systems)
reagent used in CHROMagar
PEPTONE
GLUCOSE
CHLORAMPHENICOL
species detected in CHROMagar
C. krusei
C. glabrata
true/false
CHROMagar is more sensitive than SDA and helpful in identifying mixed cultures of yeasts, and it may enhance the rapid assimilation of trehalose by C. glabrata.
true
true/false
The medium is available with or without fluconazole, providing additional selection of fluconazole resistant viz., C. krusei
true
medium used in the presumptive identification of Cryptococcus, Trichosporon, Rhodotorula spp
Christensen’s urea agar
It uses urea hydrolysis which facilitates the separation of certain dermatophytes viz., T. mentagrophytes and T. rubrum
christensen’s urea agar
reagent used in christensen’s urea agar
UREA
phenol red
used for the cultivation and differentiation of T. mentagrophytes from T. rubrum on the basis of pigment production
Cornmeal agar with 1% dextrose
Used for the differentiation of Candida species on the basis of morphological characteristics.
Cornmeal agar with Tween 80
Used as the surfactant which is specifically incorporated in lieu of dextrose for the demonstration of pseudohyphal, chlamydospores, and arthrospores formation
Tween 80
Method used in for chlamydospore production wherein it is obtained by subsurface inoculation, or by placing a cover slip over the yeast inoculum, creating a microaerophilic environment
Dalmau method