MYCOLOGY Flashcards
Chronic mucocutaneous candidiasis is associated with a lack of which immune function?
T-cell function
new yeast ‘‘buds’’
Blastoconidia
Inhibit β-glucan synthase decreasing fungal cell wall synthesis
Echinocandins
Caspofungin
Micafungin
Anidulafungin
“ringworm”
Tinea corporis
asexual spores of filamentous fungi (molds) or mushrooms
Conidia
Which organism causes fungemia in premature infants on IV lipid supplements?
Malassezia furfur
Pseudomembranous colitis
Clostridioides difficile
Blocks nucleic acid synthesis by Inhibiting DNA and RNA polymerases
Flucytosine
- endemic in Ohio and Mississippi River valleys
- grows in soil contaminated with bird droppings (starlings) or bat guano
- transmission by inhalation of airborne microconidia
HISTOPLASMA CAPSULATUM
- grows abundantly in soil containing bird (especially pigeon) droppings
- transmission by inhalation of airborne yeast cells
CRYPTOCOCCUS NEOFORMANS
DOC for coccidioidomycosis
Amphotericin B, Itraconazole
If meningitis occurs: Fluconazole
switch to a yeast growth form during infection, grow in a mycelial (mold) form at room temperature (25-30°C), and as a yeast at body temperature (37°C).
Thermally dimorphic fungi
- exist only as molds
- septate hyphae that form V-shaped (dichotomous) branches
*BRANCHING AT ACUTE ANGLES
ASPERGILLUS FUMIGATUS
live in harmony on humans, deriving their nutrition from compounds on body surfaces.
COMMENSAL COLONIZERS
- normal flora of URT, GIT, FGUT
- may appear as oval yeast with a single bud or as pseudohyphae
- form germ tubes in serum and chlamydospores in culture
CANDIDA ALBICANS
- grows abundantly in soil containing bird (especially pigeon) droppings
- transmission by inhalation of airborne yeast cells
CRYPTOCOCCUS NEOFORMANS
lack regularly occurring cross walls. These cells are multinucleate and are also called coenocytic. They often are quite variable in width with broad-branching angles
Nonseptate or aseptate hyphae
(also known as “herpes tonsurans”, “ringworm of the hair”, “ringworm of the scalp”, “scalp ringworm”, and “tinea tonsurans”) is a cutaneous fungal infection (dermatophytosis) of the scalp. It is caused by Trichophyton and Microsporum.
Tinea capitis
Fluffy surface masses of hyphae and their ‘‘hidden’’ growth into tissue or lab medium
mycelia
LABORATORY DIAGNOSIS OF FUNGI
KOH preparation
DOC for PCP
trimethoprim-sulfamethoxazole
- ingestion of contaminated peanuts and grains causes liver cancer due to aflatoxin
- aflatoxin B1 causes G:C → T:A mutation in codon 249 of p53
Aspergillus flavus
inflammatory reaction to dermatophytosis at a cutaneous site distant from the primary infection
dermatophytid reactions
Mode of transmission of Coccidioides immitis
inhalation of arthrospores