Exam 2 Flashcards

(61 cards)

1
Q

3 major approaches to the diagnosis of mycotic diseases

A

clinical settings - patient symptoms

tissue laboratory - pathology; biopsy

microbiologist & hematology

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2
Q

specimen types

A

blood, bronchoscopy, CSF, exudates, hair, skin, nails, prostatic secretions, sputum, tissue biopsies, urine SWABS ARE NOT ACCEPTABLE

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3
Q

KOH prep

A

w/ or w/o calcofluor white added will clear the background of cellular and protein material used for skin & sputum specimens

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4
Q

Lactophenol Aniline Blue

A

most common stain for scotch tape & tease mount preparations from fungal cultures may also be used to visualize yeast and FUNGAL STRUCTURES in clinical specimens

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5
Q

Sabouraud’s dextrose agar advantages

A

non-selective medium most commonly used, all molds will grow

lower dextrose & high pH = enhances fungal sporation!

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6
Q

Sabouraud’s dextrose agar disadvantages

A

contaminants will also grow; not recommended for dimorphic fungi

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7
Q

Cornmeal agar advantages

A

supports the growth of yeats and some fungal pathogens used for yeast

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8
Q

Cornmeal agar disadvantages

A

supports fungal & bacterial contaminants

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9
Q

Brain Heart Infusion with antibiotics advantages

A

prevent overgrowth of bacterial & fungal contaminants used for dimorphic fungi

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10
Q

Brain Heart Infusion with antibiotics disadvantages

A

inhibits Nocardia asteriodes, inhibits some strains of cryptococcus neoformans, inhibits yeast phase of dimorphic fungi

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11
Q

Storage of fungal specimens

A

NEVER FROZEN

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12
Q

Temperature for incubation of cultures

A

25-30*C

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13
Q

minimum time for discarding cultures

A

30 day minimum

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14
Q

Aerial

A

the portion of the mycelium growing above the surface medium from which fruiting bodies and sporulation commonly occurs

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15
Q

Aleuriospore

A

a spore or conidium that is attached laterally or terminally to the hyphae or conidiophore via a specialized cell that fragments or fractures upon detachment

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16
Q

Aseptate

A

a mycelium & hyphae that are not separated by a transverse septations & through which the endoplasm flows freely

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17
Q

Blastoconidia

A

a spore or conidium that detaches at a predetermined point of budding

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18
Q

Chlamydospore

A

a reproductive unit derived from a pre-existent hyphal cell, most commonly seen in cornmeal mounts of Candida Albucans. they may form at the apex (terminal), the side (sessile) or within (intercalary) the hypha

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19
Q

Columella

A

A terminal extension of the sporangiophore of Zygomyces species, projecting into the fertile area of a sporangium

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20
Q

Conidium

A

A term derived from the latin word ‘dust’, referring to the reproductive spores produced from the tips or sides of specialized fruiting bodies known as phialides

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21
Q

conidiophore

A

a specialized hyphal extension that supports the fruiting head from which conidia are produced

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22
Q

Dematiaceous

A

a term derived from the lain ‘ dark’, in reference to the black melanin-like pigment that is produced by many fungal species, imparting a black pigment to the colony

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23
Q

Dimorphic

A

a term that describes those fungal species, often pathogens, that grow in the mold form at environmental temperatures (25C), but as a yeast when incubated at 35C

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24
Q

Endospore

A

a spore that is produced from specialized conidiogenous cells that line a secondary structure, such as the spherules seen in coccidioides immitis, photo

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25
Hyaline
mycelium or hyphae that are non-pigmented and appear clear when viewed by transmitted light
26
Hypha
fundamental unit of a fungus; the tubular strand or filament that comprises the vegetative mycelium
27
Myceliume
the composite mat or thallus of fungal growth, made up of individual intertwining hyphae
28
Nodal
the derivation of the sporangiophores immediately adjacent to the root-like rhizoids
29
Rhizoid
root-like structures produced from the hyphae of certain species of Zygomyces that serve no particular function
30
Rugae
the folds & creases that often form on the surface of many filamentous molds
31
Septum
the transverse structure of a hypha that serves to separate individual cells
32
Philalide
the immediate cells from which conidia are produced, they do not increase in length during conidiation, in contrast to annellides
33
Vegetative
portion of a thallus or mycelium that grows beneath the surface of the substrate, in contrast to the aerial hyphae that extend airborne over the top of the medium
34
3 medically important genera of the Zygomycetes & the structural characteristics that separate them
1. Rhizopus- nodal rhizoids @ base, hyphae are not divided, white fluffly mold w/ black dots 2. Mucor- doesn't have any rhizoids/root-like structures 3. Cunninghamella- no roots/rhizoids 4. Absidia- similar to rhizopus & mucor, has rhizoids inbetween th eend of the stalks (INTERNODAL RHIZOIDS) 5. circinella- circullar or curved sporangiophores
35
3 general microscopic features that are unique to Zygomycetes
aseptate hyphae sporangium w/ spores inside most have rhizoids
36
3 clinical forms of Zygomycosis
Cutaneous pulmonary systemic
37
Aspergillus flavus
macro: yellowish/brown colony; 'lid-lifters' micro: spherical vesticle; double row of philalides ![Image result for a flavus]()
38
A. fumigatus
thermophile: grows up to 45\*C Macro: greenish-gray with white edges micro: clubbed shaped vesicle, phialides & conidia are only present on the top half of the ves ![Image result for a fumigatus]()icle
39
A. niger
macro: pepper color colony micro: doulbe row of phialides, short rows of black conidia 'dark afro' can also cause swimmer's ear ![Image result for a niger]()
40
A. terreus
macro: _cinnamon brown_ in color micro: dome shaped vesicle with long row of conidia 'fluffier' than A. fumigatus ![Image result for a terreus]()
41
Syndromes associated with pulmonary Aspergillus
1. allergic pulmonary disease: * most likely correlated with A. fumigatus or A. flavus * branched hyphae in sputum specimen is diagnostic * eosinophilia in sputum & blood samples * shark-o-laden crystals 2. fungus ball infeciton: * A. niger or A. fumigatus * grows a colony in the cavity of the lungs or sinuses * usually in ICP
42
how to determine a clinically significant fungus from a contaminant?
culture organism from multiple sites/ multiple specimens
43
Hyaline molds in general
pastel colored (except for penicillin) can cause keramytosis, mycetomas, & systemic infections usually in ICP
44
Fusarium
rapid growth : 3-5 days lavender colonies, very pretty sickle, crescent shaped multi-celled conidia causes corneal ulcers & mycetomas ![Image result for fusarium]() ![Image result for fusarium]()
45
Penicillium
rapid growth: 3-5 days yellowish, green, bluish green colonies long septate hyphae causes endocarditis, opthalmia ![Image result for penicillium]() ![Image result for penicillium](https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSjeWLsHugBSmdtHR25rA1pQDI8TNB-uEWzq8cqpR8lo2lIhbiPhw)
46
Scopulariopsis
rapid growth: 2-6 days powdery buff to brown color with radial grooves septate hyphae ![Image result for Scopulariopsis](https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSGxnaNNqhKgkj8J6rCR-SLqOcciPWpnsneLY119OCRD578z7hV)
47
Scedosporium
looks like little sperm ![Image result for Scedosporium]()
48
Gliocladium
white-greenish color 'green lawn' flask shaped phialide with a 'flower' at the end ![Image result for Gliocladium]()
49
3 features that separate hyaline molds from aspergilli
1. hyaline molds do not have a vesicle 2. hyaline molds have conidia in clusters or single; aspergillus conidia are in chains from the phialides 3. hyaline molds can have multi-celled conidia
50
T-agar
differentiat Trichopyton tonserans (will grow) from veracusum various agars with various growth requirements ( thiamine & inositol)
51
Urease test
differentiates between T. mentagrophytes (+) & T. rubrum (-)
52
Trichophyton general microscopic characteristics
macro conidia - sparse or absent; when present they can be long & pencil shaped micro conidia are abundant
53
Microsporum general microscopic characteristics
many macro conidia can have a variety of appearances usually have few micro conidia
54
Epidermophyton general microscopic characteristics
macro conidia are large & club shaped 2-5 cells per macro conidia usually do not have micro conidia
55
Microsporum Gypseum
4-7 days to grow off-white/buff color - can become more brownish after a few days macro conidia, multi-celled, bumpy wall attached directly to hyphae infects animals \> humans (skin & scalp) ![Image result for Microsporum Gypseum]()
56
Microsporum canis
5-10 day growth white w/ lemony/yellow colored apron large multicelled macro conidia with pointed ends & terminal knobs; breakaway cell attached to hyphae infected hair will fluoresce under a lamp - yellowish green no microconidia ![Image result for Microsporum canis]()
57
Trichophyton mentagrophytes
6-10 day growth produced spiral hyphae w/ micro conidia - 'clusters of grapes' & macro conidia that are smooth walled & skinny can infect hair, skin & nails positive hair bating test & positive urease test & grows on all T agars ![Image result for Trichophyton mentagrophytes]()
58
Trichophyton rubrum
7-10 days growth white/cream on top, reverse side is RED negative for hair bating test & negative/weak urease sparse microconidia - 'birds on a fence' skin & nail infections ![Image result for Trichophyton rubrum](https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcS63NO4-r5D5rDrZYe5ChZVZFE0kE5j02MpcrxdNowBi4o0PfcHvQ)
59
Trichophyton tonsurans
10-12 days suede like colony with folds 'birds on fence' micro conidia hair infection - tinea capitis ![Image result for Trichophyton tonsurans](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT5Vzqy3BIpxIHZUmeGP7SvZToU-LSDQ8bG80QuXGQIxnq3FfhXug)
60
Epidermophyton floccosum
7-10 days khaki colored colony no micro conidia skin & nail infections & atheletes foot ![Image result for Epidermophyton floccosum]()
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