Yeast Clinical Microbiology Review 271
YEAST INFECTIONS IMPORTANT CHARACTERISTICS OTHER
Candida albicans
Candida tropicalis
Geotrichum candidum
Cryptococcus neoformans
Most frequently isolated yeast. Normal
flora in GI tract, mucocutaneous
areas. Serious infections most often
in immunocompromised. Onychomy-
cosis, esophagitis common in AIDS.May produce constricted germ tubes.
(True germ tubes lack constrictions.)
Usually infects immunosuppressed.No blastoconidia.In bird & bat droppings, decaying
vegetation, fruit, milk. Capsule seen
with India ink prep in about 50% of
cases. Cryptococcal antigen test pre-
ferred. Disseminated cryptococcosis
common in AIDS.Thrush (mouth), vulvovaginitis,
diaper rash, onychomycosis
(nails), paronychomycosis
(cuticles), endocarditis,
meningitis, UTI, pulmonary
infections, fungemiaVaginitis, UTI, GI, pulmonary,
& systemic infectionsUncommon cause of wound
infections & oral thrushLung infection that can
disseminate to brainGrows on SBA, EMB (spider-like
projections), SDA. Gram-pos cells,
2–4 μm. Blastoconidia or pseudo-
hyphae (no constrictions). Produces
germ tubes in serum, round terminal
chlamydospores on cornmeal agar.Blastoconidia produced
randomly along pseudohyphae
on cornmeal agar.Forms hockey stick–shaped arthro-
conidia on cornmeal agar.Irregularly sized, spherical cells
surrounded by capsule. Maroon
to brown-black colonies on niger
seed agar. Urease pos, phenol
oxidase pos.continued...