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50 Cards in this Set
- Front
- Back
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What are the three classes of superficial mycoses?
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superficial (confined to keratinaceous stratum corneum)
cutaneous (top layers of skin, hair, nails) subcutaneous (deeper levels of skin) |
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What immediately differentiates fungi from plants?
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no chlorophyll/photosynthetic pigments.
cell wall present |
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What differentiates fungal from mammalian plasma membranes?
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ergosterols rather than cholesterols embedded in membrane.
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What is the difference between yeasts and molds?
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Yeasts = single discrete cells, reproduce by budding/fission
Molds = grow as mycelium (mass of hyphae), apical growth, conidia, sporangiophores |
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What are the asexual and sexual propagules of phylum Ascomycota?
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sexual: ascospores, >2 spores encased in saclike ascus
asexual: conidia |
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What are the asexual and sexual propagules of phylum Basidiomycota?
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sexual: basidiospores, attached to projection called a basidium.
asexual: conidia |
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What are the asexual and sexual propagules of phylum Zygomycota?
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sexual: zygospores, spiky looking
asexual: sporangiospores ( = conidia) |
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Teleomorph = ?
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sexually reproducing form of fungal spp.
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Anamorph = ?
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asexually reproducing form of fungal spp.
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Phialide = ?
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Vial-shaped cell attached to conidiophores that extrude conidia in chains.
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Conidia = ?
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Asexual reproductive structure of mold form of fungus. Produced via mitosis.
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Phialoconidia = ?
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Conidia produced/extruded by phialides.
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What does the greek root -phore mean?
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"bearer of ____"
conidioPHORE = conidia bearer basidiophore = basidium bearer |
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Ascus = ?
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saclike structure that encloses ascospores.
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Dematiaceous = ?
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describes "darkly pigmented" fungi, usually dark brown or black.
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Sporangium = ?
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thin-walled sac in which asexual spores develop.
Only in Zygomycetes. |
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Sporangiophore = ?
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differentiated hypha bearing a sporangium.
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Conidiophore = ?
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Differentiated hypha upon which conidia develop.
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Annellide = ?
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Similar to phialide; produces conidia that leave ring-like scars when they detach.
phialides don't get scars. |
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What is the purpose of lactophenol blue in fungal wet mounts?
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Phenol to kill fungus and denature enzymes (prevent cell lysis)
Cotton Blue dye to stain chitin in fungus cell wall |
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What are the distinguishing characteristics of genus Alternaria?
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Ascomycete
hyphae composed of club-shaped, dematiaceous macroconidia like teardrops linked together. poroconidia extruded through pores in hyphae |
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What are the distinguishing characteristics of genus Aspergillus?
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ascomycete
swollen bulbous conidiophores with phialides arranged dandelion-fashion, bearing chains of conidia. |
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What are the distinguishing characteristics of genus Rhizopus?
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Zygomycete
sporangiophores bear large swollen sporangium containing sporangiospores. rootlike rhizoids on opposite end of sporangiophore-bearing hyphae. |
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What are the distinguishing characteristics of genus Penicillium?
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ascomycete
conidiophore is long and slender, has phialides that make chains of conidia. paintbrush/hand looking thing |
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What are the distinguishing characteristics of genus Mucor?
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zygomycete
thick hyphae w/no septa; large bulbous sporangia but no rhizoids on opposite end of sporangiophore-bearing hyphae. |
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What are the distinguishing characteristics of genus Scopulariopsis?
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ascomycete
stubby short conidiophores that have annellides (not phialides). large conidia w/dark center and clear looking capsule structure. |
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What is the differenece between infection and colonization?
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infection = organism present and causing disease
colonization = organism present as harmless commensal |
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Pityriasis Versicolor
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Superficial mycosis; harmless/painless
skin discoloration and scaling aka tinea versicolor. caused by Malassezia furfur. |
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Seborrheic Dermatitis
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aka dandruff. caused by Malassezia furfur.
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Follicular pityriasis
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fungal infection of hair follicles by Malassezia furfur
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Malassezia furfur
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lipophilic yeast, likes sebum and cooler temps --> grows on skin surface.
basidiomycete causes pityriasis versicolor, seborrheic dermatitis, follicular pityriasis |
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Tinea Nigra
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superficial patches of dark pigmentation in palms/soles of feet
Exophialia werneckii (mold form is etiologic agent) tropical areas, females |
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Tinea pedis
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Trichophyton mentagrophytes (asco)
athlete's foot, transmitted thru contact w/contaminated skin flakes--shower rooms, etc. on webs and soles of feet: itching, scaling, cracking, inflammation, maceration (liquification) |
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Tinea capitis
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infection of hair by Trichophyton tonsurans
grey, matted hair, UV fluorescence; transmitted thru contact (barber shops) black males, economically disadvantaged areas |
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Black piedra
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Piedraia hortae, septate mold
waxy black nodules on scalp hairs esp. in males and swimmers |
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White piedra
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Trichosporon biegelii (ascomycete)
white nodules on hair in genital area, beards, mustaches. tropical areas, males |
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What are the unifying characteristics of the dermatophytes?
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-ascomycetes
-grow as septate molds -incidence of infection increases w/age |
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Tinea cruris
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"jock itch"
itching, burning, inflammation dermatophyte |
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Onychomycosis/Tinea unguium
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fugal nail infections by dermatophytes and nondermatophytes
nails deform, change color/consistency |
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Chromoblastomycosis
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unbudded, pigmented yeasts embedded in skin
etiologic agent = dematiaceous yeasts males, tropical areas, exposure to soil |
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Phaeohyphomycosis
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etiologic agent = proliferating HYPHAE (not yeasts) in tissue. like chromoblasto but with molds not yeasts.
Scedosporium prolificans no gender bias, tropics, exposure to soil, wood splinters, etc. |
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What test result differentiates between Trichophyton mentagrophytes and T. rubrum?
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hair perforation.
T. mentagrophytes perforates hair T. rubrum does not. |
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What test result differentiates Trichophyton tonsurans from other Trichophyton species?
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Thiamine-enhanced growth.
Thiamine supplementation enhances growth of T. tonsurans but not other species. |
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What structural difference separates Trichophyton mentagrophytes from other Trichophyton species?
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coiled hyphae
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Which fungi have spores and which fungi have conidia?
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Zygomycetes have spores
Ascomycetes, Basidiomycetes have conidia. same thing but different name |
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What is the microscope pointer width at 10X?
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25 um
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What is the microscope pointer width at 40X?
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6 um
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What is the microscope pointer width at 100X?
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2.5 um
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What is the structural trademark of Sporothrix?
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conidia arranged in "flowerettes"
capsulated cigar-shaped yeast cells in vivo |
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What is the structural growth pattern of most dimorphic fungi?
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Hyphae in nature
Yeast in vivo (tissue) |
