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50 Cards in this Set
- Front
- Back
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Describe the lesion associated with Actinomycosis.
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An abscess with draining sinuses, characterized by having sulfur granules in the exudate.
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What are the staining and morphological characteristics of the Actinomyces sp.?
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Fine Gram-positive filaments (may be short and branching). They are not acid fast.
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Name the two genera that contain agents that cause Antinomycosis.
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Actinomyces sp. Propionibacterium sp.
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In which anatomic location is Actinomycosis most often found?
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Cervicofacial
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What is the source of infection for Actinomycosis?
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The organism is found among the normal flora of the mouth. It is introduced into tissues by dental procedures.
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What predisposes an individual to development of Actinomycosis?
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Malnutrition.
Alcoholism. Systemic disease. Disruption of mucosal surfaces. Depressed immunity. |
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What can be seen by direct examination of pus from Actinomycosis?
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Sulfur granules.
Fine Gram-positive filaments. |
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How is Nocardiosis transmitted to humans?
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Via the pulmonary route or after trauma with a contaminated object.
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What are the etiologic agents of root- surface caries?
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Actinomycoses viscosus. Actinomycosis naeslundii.
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What predisposes a patient to development of root surface caries?
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Age.
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What is the normal habitat of Nocardia sp.?
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The soil.
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Name three different infections that can be caused by Nocardia.
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Thoracic.
Cutaneous. Meningitis. |
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What is seen when pus from a Nocardia infection is examined?
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Delicate multiple branching or fragmented filaments.
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What are the staining and morphological characteristics of Nocardia sp.?
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Gram-positive, partially acid fast, delicate filaments.
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Are fungi procaryotic or eukaryotic?
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Eukaryotic
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What is the chemical nature of the cell walls of fungi?
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Peptidomannan, chitin and glucans.
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What is a blastoconidium?
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A yeast cell (the plural is blastoconidia).
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What type of general structure do molds have?
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The are comprised of long filaments called hyphae.
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What is the name of a mass of hyphae?
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Mycelium.
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In relation to fungi, what does dimorphic mean?
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A fungal organism that can grow in two different forms depending upon the culture conditions. Often seen by growth at 37 C vs 25 C.
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What is the name for the reproductive cell of a filamentous fungus?
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Spore - it is now usually called a conidium.
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What is the term for hyphae that has no cross walls or septa?
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Aseptate or coenocytic.
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What is the term for hyphae that have cross walls?
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Septate hyphae.
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What types of spores are formed by fragmentation of thick-walled hyphal elements that are barrel shaped?
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Arthroconidia.
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What are the asexual spores that are produced when yeast cells bud?
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Blastoconidia.
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What is the name of a fungal element composed of several elongated blastoconidia that are arranged in a straight line and that appear to be hyphae?
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Pseudohyphae.
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Name the thick-walled conidium that develops within a hyphal element by modification of an existing cell.
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Chlamydospore.
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What is the name given to a very small spore (or conidium)?
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Microconidium
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What is the name given to a large spore (conidium)?
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Macroconidium.
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What is the specialized hyphal element upon which conidia are produced?
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Conidiophore.
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What is the name of a sac-like structure that contains asexual spores?
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Sporangium
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What is the name of the conidia (spores) that are contained within a sporangium?
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Sporangiospores (or sporangioconidia).
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Which class of fungi is characterized by having aseptate hyphae and sporangiospores?
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Zygomycetes.
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Which class of fungi is characterized by having ascospores and septate fungi?
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Ascomycetes.
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Which class of fungi is characterized by having basidiospores and septate hyphae?
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Basidiomycetes.
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Which class of fungi does not have a sexual stage?
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Deuteromycetes.
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What does anthropophilic mean?
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A fungus that preferentially grows on man rather than animals or in the soil.
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What does zoophilic mean?
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A fungus that preferentially infects an animal rather than man.
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What does geophilic mean?
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A fungus that has a soil reservoir.
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What is the difference between a mycotoxicoses and a mycoses?
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A mycotoxicosis is caused by a toxin that is ingested by man. A mycosis is a infection due to a fungus.
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Name four different types of mycoses.
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Superficial.
Cutaneous. Subcutaneous. Systemic. |
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Are most fungal infections from an endogenous or exogenous source?
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Most are obtained from an exogenous source.
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Which fungus is obtained from an endogenous source and where does it reside in the body?
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Candida albicans.
Found normally in the gut, mouth and vagina. |
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What is the target of attack for most of the antifungal agents?
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They interfere with ergosterol synthesis.
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What is the etiologic agent of Tinea versicolor?
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Malassezia furfur.
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What does the agent of Tinea versicolor look like when skin scrapings are digested with 10% KOH and examined under the microscope?
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Yeast cells and hyphae that look like spaghetti and meat balls.
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Which group of fungi is responsible for the ringworm infections?
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The dermatophytes.
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What is different about infection with dermatophytes as compared to the superficial mycoses?
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They infect all layers of the skin, hair and nails and produce significant lesions.
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Which three genera are involved in ringworm infections?
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Trichophyton.
Microsporum. Epidermophyton. |
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What is characteristic about to spores and hyphae of the Trichophytons?
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Thin-walled, smooth, cigar-shaped macroconidia
Numerous microconidia en engrappe (grape-like clusters) or en thyrse (along hyphae). Spiral hyphae seen. |
