Term
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Definition
| are fungi eukaryotic or prokaryotic? |
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Term
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Definition
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Term
multicellular, branching filamentous hyphae forms
unicellular yeasts |
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Definition
| types of fungal morphology |
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Term
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Definition
| in the filamentous forms of a fungus, a mass of hyphae is called a ( ) |
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Term
asexual reproduction results in spores formed by hyphae
sexular spores are less common |
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Definition
| how do filamentous fungi reproduce? |
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Term
like bacteria, fungi absorb nutrients rather than ingesting them like animals
fungi grow best in pH ~5, this is too acidic for most bacteria
fungi can grow on low moisture substances unlike most bacteria
fungi require less nitrogen than bacteria |
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Definition
| similarities and differences between bacteria and fungi |
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Term
most yeasts are facultative anaerobes
most molds are aerobes |
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Definition
| respiration of yeasts and molds |
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Term
fungal cell walls are similar architecturally to plants but not chemically; fungal cells walls are rigid
there are 3 layers of polysaccharides (glucans and glycoproteins)
also chitin and mannans are significant components of certain cell walls
[image]
ergosterol and zymosterol instead of cholesterol for the main sterol components of the cell membrane |
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Definition
| structure of fungal cell walls |
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Term
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Definition
| why are fungal cell walls not susceptible to antibiotics? |
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Term
saprophyte
most infections are caused by saprophytic fungi |
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Definition
| an organism that grows on and derives its nourishment from dead or decaying organic matter |
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Term
inhalation
ingestion
direct skin contact |
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Definition
| how are fungal infections acquired? |
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Term
low pH
fatty acids
turnover of skin
IgA at mucosal surfaces may limit growth |
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Definition
| what defenses prevent fungal colonization in the human body? |
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Term
1) hypersensitivity to fungal antigens
2) production of mycotoxins (exotoxins)
3) mycoses - growth of a fungus on or in the body |
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Definition
| through what 3 mechanisms do fungi cause disease? |
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Term
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Definition
what type of mycoses?
affects body surface (skin, hair, nails)
ex) dermatophytosis (ringworm) affects outermost keratinized tissues of the hair, nails, and stratum corneum of skin |
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Term
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Definition
what type of mycoses?
confined to the dermis, subcutaneous tissue or adjacent structures
ex) rare and confined to tropical regions of the world; usually result from inoculation of saprophytic fungi from soil into subcutaneous tissue (via a thorn, insect bite, fist spine) |
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Term
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Definition
what type of mycoses?
affects internal organs, systems
may result from inhalation of air borne spores, ingestion, or IV lines
ex) Histoplasmosis, Aspergillosis |
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Term
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Definition
infection occurs in previously healthy persons and arises through a respiratory route
type of systemic mycoses |
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Term
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Definition
cause disease in immune compromised hosts
type of systemic mycoses
endogenous example = candida
exogenous example = aspergillosis |
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Term
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Definition
infections of skin, hair, nails, and outer layers of epidermis
secrete keratinase, an enzyme that degrades keratin
ex) athlete's foot: may be an infection caused by several different fungi, including yeasts |
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Term
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Definition
capable of changing from a multicellular mold form in nature to a budding single celled form when causing infection
many pathogenic species
ex) Histoplasmosis capsulatum |
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Term
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Definition
caused by Histoplasma capsulatum
cause disease by inhalation (lung infection often mild)
bird feces provide nutrients (nitrogen) for the fungus
upon inhalation, small budding forms phagocytosed; infections of macrophages and histiocytes (fixed macrophages)
transient spread leads to flu like symptoms
hepatosplenomegaly in immunocompromised patients |
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Term
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Definition
Coccidioides immitis is the pathogen
spores found in dry soils of the Southwestern US, Central America, and South America
highly infective in dusts in endemic areas
like Histoplasmosis, may be asymptomatic; may present as flu-like illness, similar to TB
hyphal growth from lung aspirate
small percentage (~1%) of patients develop a pustular skin rash or dissemination to the bones or meinges |
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Term
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Definition
caused by Aspergillus species: A. fumigatus, A. niger, A. flavus
dangerous in immunocompromised patients
Aspergillus spores are nearly everywhere
A. fumigatus causes severe allergies
in the lung (aspergilloma) may be contained, but if it becomes systemic has a high mortality
Aspergillus flavus (from peanuts and grains) produces aflatoxin that has mutagenic effects on the liver |
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Term
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Definition
caused by Filobasidiella neoformans
encapsulated yeast that is inhaled
leads to meningoencephalitis
may also involve skin, UT, eyes, lungs, bones, joints, myocardium, prostate gland |
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Term
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Definition
caused by Pneumocystis jiroveci
opportunistic infection of elderly, premature babies, immune compromised
lung tissue infected filling the alveoli with fluid
always thought to be protozoan until recently |
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Term
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Definition
nonfilamentous, unicellular fungi; typically oval or spherical
like molds, found almost everywhere |
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Term
a number of different stains can be used to detect and characterize fungi
Gram staining can be used in certain species |
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Definition
| laboratory diagnosis of fungal diseases |
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Term
| Histoplasmosis capsulatum |
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Definition
| pathogen that causes Histoplasmosis |
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Term
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Definition
| pathogen that causes Coccidioidomycosis |
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Term
Aspergillus fumigatus
Aspergillus niger
Aspergillus flavus |
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Definition
| Pathogens that cause Aspergillosis |
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Term
| Filobasidiella neoformans |
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Definition
| pathogen that causes Cryptococcosis |
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Term
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Definition
| pathogen that causes Pneumocytsis |
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