Fungal Infections Flashcards
key virulence factor of fungus
growth
type of fungus that grows in dead and dying material
saprophytes
patients on chemotherapy
recent organ transplant recipients
predisposed autoimmune disease
patients who have higher risk of acquiring fungal infection
chitin
beta(1,3)glucan
Ergosterol
3 main things the fungal cell wall is made of
target for anti-fungals
ergosterol
main way to diagnose fungal infections
direct prep microscopy (look at morphology)
main way to direct prep
KOH w/ calcofluor
how fungal pure culture is prepared
LPCB tease mount
2 forms of fungi
yeast
filamentous
changes phase in which it grows due to change in temperature
dimorphic fungi
phase where fungus grows in dying/dead matter and at ambient temp.
saprobic phase
phase where fungus grows in us at 37 degrees celsius
parasitic phase
hyaline
no color
dematiaceous (phaeohyphomycoses)
color
grows above medium
Aerial
grows into and under medium
vegetative
infective propagules are made when
during asexual reproduction
conidia
spores
Aerial hyphae
blastoconidia
chlamydoconidia
arthroconidia
vegetative hyphae
propagule formed and ready but still attached to hyphae
conidiophore or sporangiophore
produces conidia; septate hyphae
conidiophore
produces spores; aseptate hyphae
sporangiophore
vegetative hyphae that grows as “cluster of grapes”
Blastoconidia
vegetative hyphae that has terminal endings looking like rings
chlamydoconidia
vegetative hyphae that has barrel-shaped growth
arthroconidia
host response to fungal infection
first: macrophages
second: cell-mediated
unlike bacteria, fungus do not produce what
exotoxins
fungal pathogens can be classified in 2 major ways
- mode of sexual reproduction
- site on host
main yeast
candida
main mold
aspergillus
main 3 true dimorphic fungi
blastomyces
histoplasma
sporothrix
affects skin and hair
dermatophytes
to treat: topical antifungal
superficial mycoses
pityriasis versicolor (macules on trunk) an example of what
(has spaghetti and meatballs direct prep)
superficial mycoses
affects dermis, fascia, muscle
ulcerated lesions
subcutaneous mycoses
this example of subcutaneous mycoses deals with THERMAL CONVERSION; also occupation as landscaper/gardener important
Sporotrichosis (sporothrix)
opportunistic invasive fungi
candida
systemic invasive fungi (2)
histoplasma
blastomyces
endemic in ohio river valley and are dimorphic
histoplasma
blastomyces
grows on soil and decaying leaf matter
presents w/ pneumonia and hacking cough
blastomycosis
to diagnose blastomycosis
direct prep w/ Giemsa stain (see yeast)
culture (see hyphae)
grows on bat and bird droppings
presents w/ flu-like sx’s (after spelunking)
histoplasmosis
to diagnose histoplasmosis
giemsa stain (yeast)
not true dimorphic fungi
yeast (opportunistic)
CATHETER placements
Candida
blood infections w/ candida
candidemia
most common cause of candidiasis
C. albicans
number one cause of candidiasis
Ab therapy (dysbiosis)
patient w/ HIV and diabetes has catheter removed and it had gelatinous mass on tip; he experienced rash on trunk and a fever
systemic response to candida in blood
to diagnose candida:
culture
toxicity of anti-fungal drugs
liver and renal
topical polyenes that target ergosterol and form pores (fungicidal)
Amphotericin B
Nystatin
Azole that targets ergosterol synthesis (fungistatic)
Flucanoazole
Allyamine that targets ergosterol synthesis
Terbinafine
least toxic anti-fungal
targets beta(1,3) glucan
Echinocandins
targets fungal DNA/RNA synthesis
Flucytosine
