Mycology 1 Flashcards
(100 cards)
1
Q
what is structure of fungi capsule? what is the function of this?
A
polysaccharide; antiphagocytic and virulence factor
2
Q
aka encapsulated yeast
A
Cryptococcus neoformans
3
Q
what makes up cell wall of fungi
A
polysaccharides (hexose and hexosamine polymer), proteins and glycoproteins
4
Q
energy source for fungi
A
heterotrophs or chemotrophs
5
Q
fungi grow best at pH less than this
A
5
6
Q
are yeast or molds aerobes?
A
molds
7
Q
this protects most fungi from osmotic shock
A
cell wall
8
Q
formed by fragmentation of septate hyphae into single, slightly thickened cells
A
arthrospore
9
Q
formed by rounding and enlargement within a hyphae segment
A
chlamydospore
10
Q
this if formed within a sac (sporangium) at the end of an aerial hyphae (sporangiophore)
A
sporangiospore
11
Q
what are asexual spores?
A
arthrospore, chlamydospore, sporangiospore, conidiospore, blastospore
12
Q
unicellular or multicellular spore that is not enclosed in a sac…produced at chain at end of conidiophore
A
conidiospore
13
Q
formed by a bud coming off the parent cell
A
blastospore
14
Q
what does lactophenol cotton blue stain? what structures will stain as a result?
A
chitin and cellulose; yeast cells, mycelia, fruiting structures
15
Q
what is mounting fluid for lactophenol cotton blue?
A
phenol
16
Q
three antimicrobial agents used in Dermatophytes test medium (DTM)
A
cycloheximide, chlortetracycline, gentamicin
17
Q
this is produced by dermatophytes…changes phenol red indicator from yellow, to pink, to red (in DTM test)
A
alkaline metabolites
18
Q
used for isolation/cultivation of path and non-pathogenic yeasts and molds; what enriches this growth? what inhibits?
A
Sabouraud Dextrose Agar; carbohydrate, low pH
19
Q
metabolism for fungi
A
aerobic or facultative anaerobic
20
Q
Blue-gree mold that makes Raquefort cheese
A
Penicillium roqueforti
21
Q
how yeast can divide
A
binary fission, budding, sexual
22
Q
extend below the surface of the medium for food collection (root structure)
A
vegetative mycelium
23
Q
part of mycelium above the surface, fleshy fungi (like mushrooms)
A
reproductive/aerial mycelium
24
Q
the vegetative body of a fungus
A
mycelium
25
polymers found in polysaccharides of fungal cell wall
chitin, chitosan, cellulose, a-Glucan, B-Glucan, mannan
26
sterols in cell membrane of fungi (instead of cholesterol)
ergosterol and zymosterol
27
enzyme necessary for ergosterol synthesis (lanosterol to 1 4-demethyl lanosterol)
cyto p450 1 4a demethylase
28
typical reproductive unit of fungi
spore
29
sexual spores
ascospore, basidiospore, zygospore
30
asexual spores
arthrospore, chlamydospore, sporangiospore, conidiospore, blastospore
31
formed within saclike cells (after cellular and nuclear union); sexual spore
acospore
32
formed at end of club shaped structures, sexual spore)
basidiospore
33
sexual spore...formed after cellular and nuclear fusion, large thick walled single structure
zygospore
34
this is used to detect fungi by dissolving human cells in a culture (denatures proteins in human cell but not fungus wall)
KOH
35
what is added in KOH test procedure to make structures more clear
lactophenol cotton blue
36
this relies on oxidation of carbohydrates w/in fungus to form aldehyde groups...fungus stains black
methenamine silver stain
37
carbs and glycogen oxidized to aldehydes...Reagent colors them a bright magenta color (\*polysaccharides are strongly stained\*)
PAS stain
38
india ink is used to detect these kinds of fungi (specificity is limited)
encapsulated fungi
39
makes brown colonies on growth medium containing extract of seeds of Indian thistle plant (caffeic acid in seed, oxidized by phenol oxidase)
Cyptococcus neoformans
40
what do polyenes bind to in fungi to increase membrane permeability?
ergosterol (increase membrane permeability)
41
used as oral or topical treatment for vaginal candidiasis
Nystatin
42
polyene used for disseminated fungal infections (given IV)...have severe side effects
amphotericin B
43
what makes polyenes nystatin and amphotericin B?
Streptomyces bacteria
44
azoles applied topically for superficial infections
miconazole, ketoconzaole, clotrimazole
45
azoles that treat systematic infections (such as cadidiasis, cryptococcus, histoplasmosis, blastomycosis)
itraconzaole, fluconazole, voriconazole
46
what do azoles inhibit?
cytochrome P450 (block ergosterol synthesis)
47
first step in synthesis of ergosterol (catalyzed by cytochrome P450...inhibited by azoles)
demethylation of lanosterol
48
what does flucytosine inhibit?
DNA synthesis
49
used for dermatophytes infection...binds to tubulins involved in MT formation...prevenst separation chromosomes at mitosis
Griseofulvin
50
used for dermatophyte infection...inhibits squalene eposixdase (in ergosterol synthesis)...as tables or cream
Terbinafine
51
used to treat aspergillosis, candida spp....inhibits glucan synthesis (block cell way synthesis)
Caspofungin
52
what does Caspofungin inhibit?
glucan synthesis (block cell wall synthesis)
53
what does Terbinafine inhibit?
squalene epoxidase (ergosterol synthesis)
54
infection caused by fungi
mycose
55
how is superficial dermatophytes transmitted?
direct contact with spores
56
infect most superficial area of skin...adhere to keratinized tissue...secrete keratinase...invade and grow (\*little or no host immune response\*)
superficial dermatophytes
57
two superficial dermatophytes that involved hair of scalp
black and white piedra
58
two superficial dermatophytes that involve hairless skin
Tinea versicolor and Tinea nigra
59
superficial dermatophyte that has mild to chronic colonization of stratum corneum...Tinea infection of hairless skin
Pityriasis versicolor
60
causes Pityriasis versicolor...yeast is lipophilic (needs oil)
Malassezia furfur
61
what is infected by Tinea nigra/Pityriasis nigra (\*Exophiala werneckii\*)
stratum corneum
62
presents with brown/black nonscaly macules with well defined borders; what part of body is most affected?
Tinea nigra; palms
63
treatment for Tinea nigra
oral azoles
64
diagnosis for Tinea nigra
scraping mounted in 10% KOH
65
where is Tinea nigra commonly found?
tropical climates (contact with decaying vegetation, wood, soil)
66
transmission of cutaneous dermatophytes (dermatophytosis) by these routes are easily treated
soil and animales
67
will see this on skin for diagnosis of dermatophytosis (cutaneous dermatophytes)
septate, branching hyphae or chain of arthroconidia
68
cutaneous dermatophyte genera...form dense sheath of spores around the hair (\*ectothrix\*)
microsporum
69
cutaneous dermatophyte genera...produce arthrocondidia inside hair shaft (\*endothrix\*)
trichophyton
70
cutaneous dermatophyte genera...produce thin-walled macroconidia, banana bunches
Epiermophyton
71
dermatophyte infection that infects nails
Tinea Ungulum
72
dermatophyte infection that infects fingers and palms
Tinea manus
73
these cause Tinea capitis (ringworm of scalp, hair of head, eyebrows, eyelashes)
Trichophyton tonsurans, Microsporum audouinii, M. canis, T. verrucosum
74
age group affected by Tinea capitis (scaly scalp presentation)
4/14/2015
75
responsible for more than 90% of Tinea capitis in North America and UK
Trichophyton tonsurans
76
treatments for Tinea capitis
Griseofulvin and Ketoconazole
77
what causes Tinea Cruris (aka Jock Itch)...ringworm of groing, perineum, perianal region
E. floccuosum and T. rubrum
78
sharp demarcated lesions w/ raised erthematous margin, thin dry epidermal scaling (in groin, perineum, perianal region)
Tinea cruris
79
what areas of body are typically affected by Tenia superficial dermatomycoses (brown/red de-pigmented lesions, scaly patches of skin)
back, chest, abdomen, neck, upper limb
80
diagnosis of Tinea (Pityriasis versicolor)
yellow-green fluorescence under Wood's lamp
81
what are systemic therapy options for Tinea (Pityriasis versicolor)
ketoconazole, fluconazole, itraconazole
82
shampoos that can treat Tinea (Pityriasis versicolor)
selenium sulfide, zinc pyrithione
83
what are other topicals that can treat Tinea (Pityriasis versicolor)
ciclopirox olamine, propylene glycol lotions, topical terbinafine (LAMISIL), benzoyl peroxide
84
only contagious fungal infections
cutaneous dermatomycoses/Ringworm
85
Trichophyton that cause cutaneous dermatomycoses
Rubrum, tonsurans, mentagrophytes, schoenleinii
86
Epidermophyton that causes cutaneous dermatomycoses
E. floccuosum
87
Microsporum that causes cutaneous dermatomycoses
M. audouinii
88
ringworm of the beard (bearded region of face and neck)
Tinea barbae
89
fungi that cause Tinea barbae
T. mentagrophytes and T. verrucosum
90
characterized by diffuse erythema, perifollicular papules and pustules (\*endothrix\*)...nodular lesions convered with crusts, hairs become loose and brittle
Tinea barbae
91
treatment for Tinea barbae
systemic antifungal agents
92
causes for Tinea corporis and Tinea faciei (ringworm of body, infection hairless region of skin and face)
Trichophyton rubrum, Microsporum canis, T. verrucosum, M. audouinii
93
characterstic lesions of Tinea corporis and Tinea faciei
active erythematous and spreading borders (central clearing...usually noninflammatory)
94
systemic therapy for inflammatory lesions of Tinea corporis and Tinea faciei
griseofulvin, terbinafine, ketoconazole, itraconazole
95
aka athlete's foot...infection of feet, especially the toe web soles
Tinea pedis
96
what causes athlete's foot (aka Tinea pedis)
E. floccosum, T. rubrum, T. mentagrophytes
97
what causes Tinea manus (dry scaly lesions of hand)
T. rubrum
98
what causes Tinea unguium (infection of nail plate...disfigured and distorted)
T. rubrum, T. mentagrophytes, E. floccosum
99
Tinea unguium epidemiology...more likely to happen if have these factors
older population, poor hygiene, immunodeficient, chronic water exposure
100
treatment for Tinea unguium
systemic antifungal
