Term
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Definition
-Tinea Versicolor
-Tinea Nigra (can be mistaken for melanoma); must biopsy
-Black Piedra
-White Piedra
Dx: microscopic detection of fungal structures in scrapings; calcofluor better than KOH for skin scrapings.
Tx: selenium shampoos, ketoconazole, shave off infected hair. |
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Term
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Definition
aka Dermatophytes
-Tinea (Ringworm), thrive on keratin
tinea capitis (on head), tinea unguium (nails)
-diaper rash (candida albicans)
Classification based on ecologic niche: anthropophilic, zoophilic, geophilic.
3 major genera - microsporum, trichophyton, epidermophyton flocossum (all three cause tinea/ringworm infxns).
Tx: topicals-azoles, terbinafine, griseofulvin
Cutaneous Candida species infxns - skin (candidiasis), nails (onychomycosis).
Tx: terbinafine, fluconazole, nystatin |
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Term
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Definition
-chromoblastomycoses
-Sporotrichosis
-Eumycotic mycetoma |
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Term
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Definition
| -Amphotericin B, IV, highly nephrotoxic -Nystatin (topical) Mech-binds ergosterol, an important component of the cell membrane. Tx-Candida, Cryptococcus, Aspergillus, Zygomycetes, endemic mycoses. |
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Term
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Definition
Imidazole (2 nitrogen molecules) - ketoconazole, clotrimazole, miconazole (KCM)
Triazoles (3 nitrogen molecules)-fluconazole, itraconazole, voriconazole (FIV)
Inhibits lanosterol synthesis and P-450 dependent cytochrome. |
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Term
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Definition
Terbinafine, naftifine
Inhibits squalene epoxidase, ultimately disrupting ergosterol synthesis. |
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Term
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Definition
Flucytosine-nucleotide analog
inhibits DNA & RNA synthesis; often used in combination with Amphotericin B to tx life threatening infxns.
Tx-Cryptococcus, Candida |
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Term
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Definition
the fungins
-capsofungin, anidulafungin, micafungin
All inhibit cell wall synthesis.
Tx-Candida, Aspergillus |
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Term
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Definition
non-septate hyphae
Common Pathogens:
-Rhizopus species
-Mucor species
-Absidia species
-Basidiobolus species |
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Term
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Definition
sexual stage cannot be observed.
2 types of asexual spores - thallospores & conidiospores
Thallospores have 3 types - blastospores, chlamydospores, arthrospores |
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Term
| General Characteristics of Zygomycetes & Deuteromycetes |
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Definition
1) all fungi are aerobic; obligate aerobes
2) can tolerate a wide range of pH (2-10)
3) prefer a moist environment
4) require carbon, nitrogen, and many other compounds for growth.
5) cultural media include Sabourad Dextrose Agar (SDA), SDA w/ cycloheximide. |
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Term
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Definition
| unicellular and reproduce asexually via a process called budding. |
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Term
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Definition
| a mold form; may be septate or non-septate (coenocytic) |
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Term
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Definition
mass of hyphae (i.e. mould)
vegetative mycelium - grows into (Rhizoids, like roots)
aerial mycelium - sticks out (like flowers) |
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Term
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Definition
| specialized structures arising from aerial hypahe or mycelium. |
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Term
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Definition
Yeast cells that elongate and link together like sausages which represent exaggerated form of budding.
Candida |
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Term
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Definition
| produce no mycelium and reproduce by budding |
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Term
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Definition
| specialized large, thick-walled spores that resist periods of dormancy. |
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Term
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Definition
| segmentation of septate hyphae by constriction to produce rectangular or pillow-shaped thick walled spores. |
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Term
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Definition
Tinea versicolor, superficial mycoses
-lipophilic, so it cannot be grown in labs b/c it requires lipids. |
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Term
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Definition
Tinea nigra, superficial mycoces.
commonly mistaken as melanoma. |
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Term
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Definition
| White piedra, superficial mycoses |
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Term
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Definition
Black piedra, superficial mycoses
contains black pigment in cell wall. |
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Term
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Definition
Sporothrix schenkii, subcutaneous infxn.
Chronic infxn characterized by nodular and ulcerative lesions that develop along lymphatics that drain primary site of infxn - Rose Gardeners Disease
Dimorphic fungus
Tx: oral saturated soluton of potassium iodide. Extracutaneous - tx w/ amphotericin B. |
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Term
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Definition
lesions have cauliflower like appearance.
Infxn caused by any one of a group of fungi referred to as dematiaceous (dark colored cell wall).
On biopsy brown spheres are pathognomonic.
Tx: terbinafine or itraconazole w/ flucytosine. surgical excision for refractory case. |
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Term
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Definition
disease is characterized by indolent, deformed, swollen lesions that contain numerous draining sinus tracts.
Caused by a variety of different fungi including Actinomyces and Nocardia species.
Dx: histologic exam of biopsy showing sulfur granules in tissue.
Tx-if fungus, surgical excision; i nocardia, bactrim; if actinomyces, penicillin. |
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Term
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Definition
aka. Darling's Disease or Spelunker's disease; Dimorphic
-endemic to central miss, ohio, st. lawrence river valleys.
-organism grows well in high nitrogen content - bird or bat droppings.
-disease results from inhalation of spores.
Dx-microscopic exam of tissue showing small intracellular yeast in macro.
Tx-Amphoteracin B followed by fluconazole |
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Term
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Definition
Dimorphic
-occurs primarily in north america; miss & ohio; natural disease occurs in dogs and horses.
Clinical-symptomatic infxn uncommon; spores inhaled and convert to yeast -> macrophages ingest and disseminate to other organ; preference for skin.
Dx-broad based budding yeast
Tx-Amphoteracin B for severe disease; itraconazole or fluconazole for less severe. |
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Term
| Paracoccidioides brasiliensis |
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Definition
-Central and South America; exist in soil w/ high humidity; Dimorphic.
Clinical-oral & nasal lesions common.
Histo-spherical yeast: Ship's Wheel
Tx-Amphoteracin B for severe; Itraconazole for less severe. |
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Term
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Definition
-semi arid southwest; mold produces arthrospores in soil that are highly infxious when inhaled.
Clinical-mild febrile to moderately severe pulmonary syndrome (40% of people develop symptoms)
Histo-spherules filled with endospores.
Tx-Amphoteracin B followed by fluconazole or itraconazole; most patients do not require tx. |
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Term
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Definition
| A true yeast; NOT dimorphic; fungal MENINGITIS!!! found in bird shit. -possess an acidic mucopolysaccharide capsule required for pathogenicity. -Pulmonary infections usually asympto, but can cause pneumonia w/ diffuse pulm infiltrates. Hematogenous spread to meninges; cutaneous infxns can occur. Dx-India Ink of CSF very insensitive; test for antigen. Tx-Amphoteracin B w/ flucytosine |
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Term
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Definition
Dimorphic; prominent mycotic pathogen in HIV infected patients in SE Asia.
Major reservoir-bamboo rats & soil
Clin-mimic TB or other HIV-related opportunistic infxn.
Tx-Amphoteracin w/ or w/o flusytosine |
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Term
| Which fungi is/are capable of systemic infections are not dimorphic? |
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Definition
| Cryptococcus neoformans; a true yeast. |
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Term
| General Characteristics of Systemic Mycotic Agents |
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Definition
the lung is the primary, but not exclusive, focus of infxn for all agents.
most respiratory infxns are subclinical or mild w/ a short duration of symptoms that resolve w/o thx.
secondary spread may occur outside lungs requiring pt to seek medical attention. |
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