Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Myco > Yeast > Flashcards

Yeast Flashcards

Midterm (101 cards)

Start Studying
1
Q

it is the main factor why yeasts have been prevalent

A

immunosuppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

infections caused by yeasts may be — and —

A

extremely aggressive and difficult to treat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

t or f: yeast is often part of the human microbiota

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

yeasts can be classified into

A

yeast (mostly asexually but able reproduce sexually) and yeast-like (not capable of sexual reproduction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

generally, yeasts can reproduce asexually through —, but they can also reproduce sexually through —

A

asexually= blastoconidia (budding); sexually= ascopores and basidiospores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

give the general characteristics of yeast

A

eukaryotic, unicellular, round-oval, 2-60um, reproduce asexually (blastoconidia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the characteristics for differentiation of yeasts

A

cell size, presence and absence of capsule, budding phase (broad, narrow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

diiferentiation of yeast in — and — is ften impossible

A

direct microscopy and histopathologic examination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

an outpouching of the cell wall that becomes tubular and does not have a constriction at its base

A

germ tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

it represents the initial stage of true hyphae formation

A

germ tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

buds elongate, fail to dissociate, and form subsequent buds

A

pseudohyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

resemble links of sausage

A

pseudohypahe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

have cell wall constrictions rather than true intracellular septation delineating the fungal cell borders

A

pseudohyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

macroscopic appearance of yeasts

A
  • moist
  • creamy
  • may have brght pigments
  • either hyaline/melanized (phaeiod)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

t or f: some yeasts may produce a capsule resulting in a shiny or mucoid colonial appearance

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

this is responsible for most commonly encountered opportunistic fungal infection

A

candida spp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

candida spp is the — most common cause of hospital acquired bloodstream infection (BSI)

A

4th most common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

mortality rate of candida spp

A

as high as 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

this is the most commonly isolated yeast

A

Candida albicans which causes candidiasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the symptoms/clinical manifestations of candidiasis

A

oroesophageal candidiasis, intertriginous candidiasis, paronychia, onychomycosis, vulvovaginitis, thrush

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what specific clinical manifestation of candidiasis: skin folds are involved

A

intertriginous candidiasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what specific clinical manifestation of candidiasis: involves tissues surrounding the nails

A

paronychia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what specific clinical manifestation of candidiasis: affects nail and nail beds

A

onychomycosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what specific clinical manifestation of candidiasis: fish eye

A

vulvovaginitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what specific clinical manifestation of candidiasis: an infection of the mucous membranes in the mouth, and is considered a localized infection
thrush
26
what specific clinical manifestation of candidiasis: can be seen in newborns, patients with HIV, and diabetes
thrush
27
thrush is infection of candida albicans in what areas
mouth
28
t or f: thrush caused by candida albicans is a localized infection
true
29
thrush can be seen in what patients
newborns, HIV, diabetes
30
enumerate the non-albicans candida
C. glabrata and C. parapsilosis
31
these are once believed to not cause diseases
non-albicans candida
32
t or f: non-albicans candida was once believed to not cause disease
true
33
it is a common urinary isolate candida
C. glabrata
34
C. glabrata can be differentiated with C. albicans through
sugar (trehalose) assimilation
35
this candida is resistant to antifungal drugs
C. glabrata
36
infections caused by C. glabrata can cause
endocarditis and meningitis
37
C. glabrata is higher in what population
higher in older adults than in young adults and children
38
this candida is seen in neonates
C. parapsilosis
39
this candida is the 2nd most common cause of positive blood culture
C. parapsilosis
40
what candida is positive for germ tube
C. albicans
41
laboratory diagnosis of Candida
Microscopic appearance and testing for germ tube (only albicans is +)
42
t or f: in microscopic appearance of candida reveals budding cells
true
43
diameter of candida in microscopy
2-4um
44
in microscopic appearance of candida --- shows regular points of constrictions
pseudohyphae
45
what candida demonstrates true septate hyphae
C. albicans
46
this candida have a smaller blastoconidia at 1-4um
C. glabrata
47
t or f: yeasts are hard to treat because they are hard to distinguish from each other
true
48
how to do germ tube
add yeast colony to 0.5mL serum
49
possible samples for yeast determination
- vaginal discharge - urine - sputum - stool - wound discharges (oberved through gram stain) - blood culture
50
what part of the body is vulvovaginitis be observed
vaginal canal up to cervix (causes bad odor)
51
thrush is very evident in what part of the body
tongue
52
this is one of the diagnostic testing done to do to differentiate yeasts
temperature
53
this causes meningitis, pulmonary disease, and septicemia
cryptococcus spp
54
these are the most common routine tests done to identify yeasts
germ tube and india ink
55
it is the major cause of opportunisitc infections in people with AIDS
cryptococcus
56
cryptococcus is commonly found in
soil contaminated with pigeon droppings
57
cryptococcus most common specimen
CSF (most routine for india ink testing)
58
cryptococcus can be acquired through
inhalation
59
this is the mst notable pathogen of the cryptococcus spp
C. neoformans
60
this protects the cryptococcus from dry condition
polysaccharide capsules
61
the main way of identifying C. neoformans using india ink using microscopy
capsulated budding yeast
62
t or f: cryptococcus loves dry conditions
false, they prefer mucoid/wetter environment
63
the most widely used and easiest method to test cryptococcus
india ink
64
this testing method is able to delineate the large capsule of cryptococcus spp due to the inability of the ink to penetrate the capsule
india ink
65
ratio of sample and india ink
1 drop sample (CSF):1 drop india ink
66
disadvantage of india ink
less sensitive
67
this is an immunoassay type of testing for cryptococcus
cryptococcal antigen detection (CAD)
68
t or f: india ink is more sensitive than **cryptococcal antigen detection (CAD)**
false, CAD is more sensitive
69
can be misidentified as positive for india ink
bubbles, WBCs
70
t or f: clear capsule/halo of capsule indicates bubbles or WBCs
false, clear halo means it is **true positive for india ink**
71
t or f: C. neoformans can only have single budding
false, it can have **single** or **multiple** budding
72
shape of C. neoformans
spherical
73
describe the wall of C. neoformans
thick-walled (due to capsule)
74
size of C. neoformans
**2-15 um** in diameter
75
t or f: polysaccharide capsule is true for all cryptococcus spp
false, it is true to most isolates but not all
76
this is an opportunistic, atypical fungus
pneumocystis
77
pneumocystis can be acquired
in early life
78
t or f: pneumocystis infection is asymptomatic for immunocompetent individuals
true
79
this yeast is first considered as a protozoan
pneumocystis
80
fun fact: pneumocystis is classified as yeast instead of protozoan (parasite) after what test
DNA testing
81
this pneumocystis is previously classified as protozoan and is commonly found in rats
P. carinii
82
this pneumocystis is often recovered from humans
P. jirovecii
83
other tests for the identification of yeasts
- carbohydrate assimilation - chromogenic substrates (CHROMagar) - cornmeal agar - potassium nitrate assimilation (KNO3) - Urease
84
t or f: EIA can be used for yeast identification
true, but are not readily available, rigorous, and expensive so its not routinely used
85
this is also called sugar fermentation test
carbohydrate assimilation
86
this test is used to identify which carbohydrates a yeast can use aerobically as a sole carbon source
carbohydrate assimilation
87
what are observed or the indications in sugar fermentation (carbohydrate assimilation) test
turbidity, change in color, indicators
88
this test can be used to differentiate species of candida
chromogenic substrates (CHROMagar cacndida)
89
this is a differential type of media, especially in candida spp (you can observe the different colonial growth patterns)
CHROMagar candida
90
this presumptively identifies C albicans, C tropicalis, and about 10 other candida spp
CHROMagar candida
91
t or f: if you get colonies from CHROMagar, it reveals their true morphologic characteristics microscopically
true
92
this allows the identification of morphology of yeasts, not just that of candida
cornmeal agar
93
what morphologies can you observe from colonies of cornmeal agar
- blastoconidia - chlamydoconidia - pseudohyphae - arthroconidia
94
this determines the ability of yeasts to use nitrates as the sole source of nitrogen
potassium nitrate assimilation (KNO3)
95
what yeast is the positive control for KNO3
Cryptococcus albidus
96
what is the negative control for KNO3
Candida albicans
97
this is used for the detection of isolates producing the enzyme urease through **christensen urea agar**
urease
98
what agar is used for urease test
Christensen urea agar
99
this clinically significant yeast is negative for urease
Candida spp
100
t or f: most Cryptococcus are negative for urease
false, they are mostly positive
101
what indicator is observed if urease test is positive
there will be a **change in color of the media**

Myco (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions