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34 Cards in this Set
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Pityriasis (Tinea) Versicolor
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Etiology: Malassezia furfur
Epidemiology: Worldwide Clinical syndromes Pityriasis versicolor Pityriasis follicullitis Seborrheic dermatitis & dandruff |
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m. furfur
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in culture sabouraud's dextrose agar containing cycloheximide (actidione)
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A superficial fungal infection of skin characterized by black macules of the palms of the hands and occasionally the plant and other surfaces of the skin
Epidemiology: Tropics Etiology: Hortea werneckii (formerly Exophiala werneckii) |
Tinea nigra
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tinea nigra
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caused by hortaea werneckii
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Superficial cosmetic fungal infection of the hair shaft
Epidemiology: Tropics |
Etiology: Trichosporon beigelii
T. inkin T. asahii T. mucoides |
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white pidera culture
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yellowish to cream fluffy colonies typical of Trichosporon species.
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Superficial fungal infection of hair shaft
Epidemiology: Central & South America, SE Asia. Poor hygiene |
Etiology: Piedra hortae
firm, irregular black nodules along hair shaft |
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tinea pedis
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T. rubrum
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tinea pedis; moccasin type
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caused by e. floccosum
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tinea pedis; vesicular type
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caused by t. interdigitale
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Onychomycosis; organism?
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T. Rubrum and T. interdigitale are most commonly involved
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tinea capitis
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caused by microsporum canis (same as corporis)
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tinea corporis
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caused by microsproum canis; same as tinea capitits
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tinea barbae
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caused by e. floccosum
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causes tinea capitits and corporis
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microsporum canis
cultured in dish macroscopic, |
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Chronic mycotic infection of the cutaneous or subcutaneous tissues and adjacent lymphatics characterized by nodular lesions which may suppurate and ulcerate.
Infections are caused by the traumatic implantation of the fungus into the skin Epidemiology: North & South America, Japan |
Etiology: Sporothrix schenkii
Lives on woods & plants Dimorphic fungus –mold in environment; yeast in tissues Causes a chronic granulomatous infection that can spread along the lymphatic system Can cause a fix cutaneous lesion at the site of implantation of the fungus Sporotrichosis |
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Mycotic infection of cutaneous and subcutaneous tissues characterized by the development brown sclerotic bodies
Caused by traumatic implantation Chronic, slow progressive, localized Epidemiology: worldwide, bare footed population |
Etiology:
Phialophora verrucosa Fonsecaea pedrosoi Fonsecaea compacta Cladophialophora carrionii |
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Skin scrapings from a patient with chromoblastomycosis mounted in 10% KOH and Parker ink solution showing characteristic brown pigmented, planate-dividing, rounded sclerotic bodies
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Cultures of the aetiologic agents of chromoblastomycosis are typically olivaceous-black with a suede-like surface.
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Nappy rash" candidiasis in an infant which spread to the mouth area.
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Arthroconidia
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an asexual spore which is the product of separation and fragmentation of true fungal hyphae
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Sporangiasphore
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specialized aerial structure that produce sporangia- sacs containing asexual spores
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Conidiosphores
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specialized aerial structures that consist of phialides ( aerial hyphae) which produce conidia.
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Dermatophytosis
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Dermatophytosis (tinea or ringworm) of the scalp, glabrous skin, and nails is caused by a closely related group of fungi known as dermatophytes which have the ability to utilize keratin as a nutrient source, i.e. they have a unique enzymatic capacity [keratinase].
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Lactopenol Aniline Blue
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stains the outer wall of molds, aiding in the microscopic examination of the fungal mycelium and fruiting structures.
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KOH examination
It is particularly useful when examining thick mucoid material or specimens containing keratinous material such as skin scales, nails, or hair. The KOH digests the cellular material and background keratin, revealing the fungal elements and making them more visible. |
or the direct microscopic examination of skin scrapings, hairs and nails for fungal elements.
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Periodic acid-shiff (PAS) stain
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or the demonstration of glycogen and neutral mucins. Useful for the detection of fungal elements in tissue sections
certain tissue elements are oxidized by periodic acid to produce aldehydes. These aldehydes will react with Schiff's reagent to produce a magenta colored compound |
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Calcoflour white
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For the direct microscopic examination of skin scrapings, hairs, nails and other clinical specimens for fungal elements. But requires a fluorescence microscope
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Gimesa stain
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Fungi are typically gram positive also although there are some that can’t pick up the crystal violet and so appear pink.
Giemsa stain is especially useful for detected the intracellular yeast forms like Histoplasma capsulatum. |
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Grocott's Methenamine silver stain (GMS)
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for the detection of fungal elements in tissue sections.
Chromic acid treated fungi possess aldehydes which will reduce the hexamine-silver mixture to produce a black deposit. Fungi stain black. |
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blood containing media
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Some fungi, like Histoplasma capsulatum and Blastomyces dermatitidis require blood- containing media ( BHI + 5% - 10% sheep blood)
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antibiotic additives in fungi culturing
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Samples taken from areas potential laden with bacteria should be inoculated onto media with antibiotics.
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primary isolation media for fungal yeast and mold cultures
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Brain heart infusion media (BHI) and SABHI (Sabouraud, dextose, and BHI) are the primary isolation media for fungal yeast and mold cultures.
Potato Dextrose is another routine cultivation agar for fungi |
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which fungi requires olive oil (or other LCFA) in its culturing
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Malassezia furfur, an fungal agent that causes superficial skin infection and infections of vascular catheters, required a medium containing olive oil or another source of long-chain fatty acids.
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Mold
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Yeast
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