Medical Mycology Terms/Basics Flashcards
some yeast elongate and ahere to one another forming
pseudomycelium/pseudohyphae
microconidia
small single-celled conidia
arthroconidia
asexual reporductive element
single-celled conidia that are formed by the disjoining of hyphal cells
serological methods are especially useful in…
systemic fungal diseases
possible effective drug combination strategies (4)
- inhibition of different stages of the same biochemical pathway
- increased penetration of one agent into the cell through a permeabilizing activity of another agent
- inhibition of the transport of one agent out of the cell by another agent (reserpine inhibits efflux pumps with azole)
- simultaneous inhibition of different fungal cell targets
resistance of echinocandins
resistant organisms have point mutations in the subunits of the glucan synthesis target
sensitivity to polyene and azole drugs retained
function of amphotericin B
bind to ergosterol, direct membrane damage
most of our understanding about resistance to antifungal agents comes from observations of
C. albicans as well as other species of Candida
mechanism of flucytosine
disrupts nucleic acid synthesis in the nucleus
what are ergot alkaloids?
family of related compounds that can lead to gangrene, nervous spasms, psychotic dilusions, muscle contractions, BV constriction
LSD was discovered through these
function of allylamines
they interfere with ergosterol biosynthesis, targeting cell membrane
what are rhizoids?
rootlike structures
function of griseofulvin
dirupt microtubules and mitosis
resistance to antifungal drugs can occur through:
- efflux pumps
- target alterations
- reduced access to drug targets
what is mycelium?
a mass of intertwined hyphae that accumulate during active growth
chlamydoconidia
asexual reporductive element
thick-walled single cells that are resistant to adverse conditions
function of echinocandins
inhibit glucan synthesis, inhibit cell wall
the term for organisms living on dead organic matter
saprobe/saprophyte
conidiospores
asexual reporductive element
medically important spores that are borne naked on specialized structures (macro/microconidia)
resistance to azoles
- increased expression of efflux pumps
- decreased affinity of the target enzyme for the drug
- increased expression of the target enzyme
- alternative metabolic pathways leading to synthesis of ergosterol
TRUE OR FALSE:
the use of azoles in agriculture doesn’t affect resistance in the clinic
FALSE, it contributes to resistance in the clinic
macroconidia
large, multicelled conidia
three types of hyphae
- nonseptate (coenocytic)
- septate, uninucleate cells
- septate, multinucleate cells (coenocytic)
do fungi destroy antifungal drugs?
no, they do not destroy or modify antifungal drugs
eagle effect
definaed as an organism that is resistant to high concentrations of the drug but susceptible to low concentrations
what is aflatoxin
produced by Aspergillus flavus, is a mutagenic/carcinogenic and often a contaminant of peanuts, corn, grains, and other food
serological methods
ELISA
precipitation tube test
complement fixation test
latex agglutination
resistance to polyenes
not common
mechanism: reduction of ergosterol in resistant organisms, masking ergosterol in the cell membrane
prevents amphotericin B binding
resistance to allyamines
not a result of resistance to the drug, but is due to the CDR1 multidrug efflux pump
resistance to flucytosine
THIS RESISTANCE IS COMMON—OFTEN USED IN COMBINATION THERAPY
alterations in the permease that reduces uptake of the drug
alterations in any of the enzymes necessary for conversion to the active metabolites
sporangiospores
asexual spores
medically important single-celled spores that are formed within sacs called sporangia from the end of a special hyphae (sporangiophores)
ingestion of mushrooms of the Amanita species result in what?
severe or fatal liver and kidney damage by alpha-amanitin inhibiting RNA polymerase II
amphotericin B is a
polyene
sporangiophore
special hyphae that has a sporangium extending from it that forms sporangiospores
blastoconidia
asexual reporductive element
budding
function of azoles
they interfere with ergosterol biosynthesis, targeting cell membrane
asci/ascospores
type of sexual spore
what type of drug is terbinafine and what does it do?
Allylamine
interferes with ergosterol biosynthesis, targeting cell membrane
