Test Answers on Final Exam – Flashcards
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| Blastomyces dermatitidis in tissue |
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| thick walled yeast with broad based budding |
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| Coccoidiodes immitis in tissue |
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| non-budding, thick walled spherule which contains non- budding endospores |
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| Histoplasma capsulatum in tissue |
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| small yeast seen in bone marrow |
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| Paracoccidiodes brasiliensis in tissue |
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| large, oval budding yeast |
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| Sporothrix schenkii in tissue |
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| cigar-shaped yeast cells |
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| Penicillium marneffei in tissue |
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| small yeast, non-budding with cross walls |
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| Blastomyces dermatitidis as mold |
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| front is white to brown, reverse is tan, septate hyphae with pear shaped conidia |
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| Coccoidiodes immitis as mold |
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| front is white to brown, reverse is white/gray, septate branched hyphae with barrel shaped arthroconidia alternating with empty cells |
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| Histoplasma capsulatum as mold |
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| front is pink/white, reverse is white to orange/yellow, septate hyphae with pear-shaped tuberculate macroconidia |
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| Paracoccidiodes brasiliensis as mold |
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| front is white, glabrous, heaped and brown, septate hyphae with intercalary and terminal chlamydospores and microconidia |
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| Sporothrix schenkii as mold |
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| cigar-wrinkled, tan, black, thin septate hyphae with delicate roses |
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| Penicillium marneffei as mold |
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| reddish brown with a blue center, reverse is red |
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| List 4 species of Trichophyton |
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| Trichophyton mentagrophytes, Trichophyton rubrum, Trichophyton tonsurans, and Trichophyton schoenleini |
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| Characteristic of all Trichophyton |
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| all dermatophytes with septate hyphae, thin-walled, smooth macroconidia and numerous microconidia |
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| Trichophyton mentagrophytes morphologic characteristics |
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| coiled spirals, cigar macroconidia, and round microconidia on branched conidiophores |
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| Trichophyton rubrum morphologic characteristics |
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| small tear drop microconidia borne laterally on hyphae |
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| Trichophyton tonsurans morphologic characteristics |
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| - spirals and arthroconidia, balloon microconidia |
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| Trichophyton schoenleini morphologic characteristics |
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| antler-like branches, numerous chlamydioconidia |
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| 3 species of Microsporum |
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| Microsporum audouinii, Microsporum canis, Microsporum gypseum |
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| characteristic of Microsporum |
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| - all dermatophytes with septate hyphae and thick-walled tough macroconidia |
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| Microsporum audouinii morphologic characteristics |
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| pointed terminal chlamyoconidia, pectinate hyphae, poorly shaped macroconidia |
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| Microsporum canis morphologic characteristics |
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| - spindle-shaped macroconidia, knob like ends, club shaped sparse microconidia |
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| Microsporum gypseum morphologic characteristics |
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| numerous, rough macroconidia with round ends and thin walls with > 6 walls |
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| Epidermophyton floccosum morphologic characteristics |
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| thin and thick walled, smooth macroconidia, no microconidia, club shaped macroconidia thin and thin in clusters |
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| Penicillium |
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| conidiophores branch into a brush |
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| Scopulariopsis |
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| short and simple conidiophores with annellides that bear conidia which are thick walled, lemon shaped and cut off at base |
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| Acremonium |
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| delicate septate hyphae with erect phialides, oblong conidia in clusters at the tip of the phialides |
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| Paecilomyces |
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| phialides are elongated and taper into tenpins which bend away from the conidiophore, elliptical conidia in unbranched chains |
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| Gliocladium |
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| conidiophores with brush-like phialides, conidia do not chain, they clump into clusters |
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| Trichoderma |
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| short and branched conidiophores, with flask-shaped phialides and round cell conidia clustered at the end of the phialides |
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| Fusarium |
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| (1) short conidiophores with 1-2 cell conidia in clusters or (2) branched/unbranched conidiophores bearing large sickle shaped multiseptate macroconidia |
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| Alternaria |
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| dematiacious mold with dark hyphae, septated conidiophores that zigzag, brown, club-shaped conidia with transverse AND longitudinal septa |
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| Phialophora |
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| dematiacious mold, slow growing, brown, branched, septate phialides, vase-shaped with flared cup-like collerette, round-oval conidia that accumulate at apex of the phialides |
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| Bipolaris |
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| dematiacious mold with bent conidiophores, brown, thick, walled, oblong conidia with cylindrical septations and protruding hilum |
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| Exophiala |
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| dematiacious mold, slow growing, yeast-like budding cells, septate hyphae with slender annellides that taper, oval conidia that cluster along the sides of the annellides |
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| Cladosporum |
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| dematiacious mold with branched conidiophores with 2 branching single celled conidia, brown, oval, dark with dark hila |
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| Curvularia |
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| dematiacious mold with bent conidiophores, 4 chambers in conidia with dark cell center and bent/curved conidia with age |
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| Aspergillus fumigatus |
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| conidiophores are short and smooth, terminate in swollen vesicle with uniseriate phialides on 2/3 upper portion of the vesicle which is parallel to the axis of the conidiophore |
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| Aspergillus niger |
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| conidiophores are rough, variable length, pitted and spiny, terminate in swollen vesicle with biserate phialides that cover the entire vesicle and radiate from head with black conidia |
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| Exerophilum |
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| dematiacious mold with bent conidiophores, brown, long, thick walled conidia with 7-11 septations, conspicuous spare hilum |
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| Scedosporium |
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| septate hyaline molds with single conidia, conidiophores with oval, truncated conidia |
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| Pseudoallescheria |
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| cleistothecium is large, round and closed, dematiacious mold |
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| Annellides |
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| a cell that produces and extrudes conidia; tapers and lengthens with each condidum |
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| Phialides |
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| a cell that produces and extrudes conidia; does not taper or lengthen with each condidum |
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| Chlamydospores |
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| thick-walled big resting spore of several kinds of fungi. It is the life-stage which survives in unfavourable conditions, such as dry or hot seasons. |
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| Arthroconidia |
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| An asexual spore formed by the breaking of hyphae at the point of septation |
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| Rhizoids |
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| a filamentous structure of fungi that extends into the substrate |
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| Ascospores |
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| sexually produced fungal spore formed within an ascus |
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| Ostioles |
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| A small pore through which spores are discharged |
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| Germ Tube |
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| tubelike process, produced by germinating spore that develops into mycelium |
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| Psuedohyphae |
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| : A chain of easily disrupted fungal cells that is intermediate between a chain of budding cells and a true hypha, marked by constrictions rather than septa at the junctions. |
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| Sporangium |
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| a closed sac-like structure in which asexual spores are formed by cleavage |
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| Dimorphic |
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| fungi with both a mold phase and a yeast phase |
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| Dematiaceous |
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| presence of pigmentation in fungal hyphae or spores |
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| Dermatophyte |
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| a fungus parasitic on skin, hair, or nails |
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| Characteristics of Chromoblastomycosis |
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| : localized cutaneous or subcutaneous infection, tissue has rounded and sclerotic bodies (copper pennies) |
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| Organisms associated with Chromoblastomycosis |
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| dematiacious molds |
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| Characteristics of Phaeohyphomycosis |
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| cutaneous, subcutaneous or systemic, tissue is dark, with yeast-like cells with pseudo-hyphae-like elements |
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| Organisms associated with Phaeohyphomycosis |
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| dematiacious mold |
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| Characteristics of Mycetoma |
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| seen on hands and feet, chronic infection, tumor-like lesions, granular pass (mass of mycelia) |
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| Organisms associated with Mycetoma |
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| Pseudoallescheria boydii, Acremonium spp. (white grain), Exophiala jeanselmei, Curvularia, and Madurella mycetomatis (black grain) |
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| Characteristics of Mucormycosis |
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| vascular invasion, rapid thrombosis and necrosis of tissue Organisms associated with Mucormycosis: Mucor spp.- zygomycetes |
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| The germ tube test |
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| Identification of C. albicans within 3 hours via presence of germ-tubes (positive) |
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| Phenol Oxidase test |
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| C. neoformans can produce phenol oxidase. Phenol oxidase can be reacted with phenylalanine and ferric citrate to oxidase diphenol to melanin which produces a brown/black color, C. albicans is negative |
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| Urease Test |
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| used on respiratory specimens, rapid detection of C. neoformans (+) because this species can hydrolyze urea (using urease) to ammonia and carbon dioxide, which changes the indicator from yellow to pink, C. albicans will be negative |
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| C. albicans |
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| germ tube positive, most frequently isolated etiologic agent, |
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| C. tropicalis |
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| germ tube negative, blastoconidia off of pseudohyphae, sometimes seen at septa |
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| C. glabrata |
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| germ tube negative, tiny, budding yeast, no pseudohyphae |
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| Cryptococcus neoformans |
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| Urease positive, Phenol oxidase positive, lives in pigeon dropping, can cause meningitis, has a polysaccharide capsule, and on cornmeal produces blastoconidia only |
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| Rhodotorula spp |
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| causes opportunistic endocarditis and fungemia, salmon colored and has a capsule, urease + |
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| What is the family/group of molds that produce aseptate hyphae? |
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| Zygomycetes produce aseptate hyphae |
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| Zygomycetes |
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| Rhizopus, Mucor and Absidia |
