MYCO & VIRULOGY L1 (Prelim- Introduction) Flashcards
1
Q
What are the general characteristics of a Eukaryotic cell?
A
- Posses true nucleus
- Nuclear membrane
- Mitochondria
2
Q
What are the 2 types of fungi?
A
- Yeast
- Mold
2
Q
Enumerate at least three characteristics of a fungi
A
- Chitin in cell wall
- Ergosterol in the cell membrane
- Sexual or asexual reproduction
- Lack chlorophyll
- Lack antibiotic susceptibility
- Saprophytic
3
Q
General considerations for the identification of Yeasts
A
- Colonial morphologic features
- Microscopic morphologic features
- Psychologic studies
- Rapid commercial yeast identification tests
4
Q
Most fungi are __________ that grow best at a _______, although they tolerate a wide pH range
A
obligate aerobes; neutral pH
5
Q
IDENTIFY: Single vegetative cells (unicellular). Moist, creamy, opaque or pasty colonies on media
A
Yeast
6
Q
Yeast reproduces through?
A
“budding”
7
Q
This is the term used to describe the daughter cell in “budding”
A
Blastoconidium
8
Q
General considerations for the identification of Molds
A
- Growth rate
- Colonial morphologic features
- Microscopic morphologic features
9
Q
IDENTIFY: Filamentous Fungi. It has fluffy, cottony, woolly or powdery colonies
A
Molds
10
Q
Most molds have a fuzzy or woolly appearance because of
the?
A
formation of mycelia
11
Q
Mycelia are made up of
many long strands of tubelike structures called?
A
hyphae
12
Q
Hyphae can be classified as?
A
Aerial or Vegetative
13
Q
These mycelia extend above the surface of the colony and
are responsible for the fuzzy appearance
A
Aerial mycelia
14
Q
This support the reproductive structures that produce conidia
A
Aerial mycelia
15
Q
In many cases, these are used to identify different fungal genera
A
Conidia
16
Q
These mycelia extend downward into the medium to absorb nutrients
A
Vegetative mycelia
17
Q
Enumerate the three different kinds of septation in a hyphae
A
- Septate
- Sparsely septate
- Aseptate
18
Q
Enumerate the four different appearances of a hyphae
A
- Antler hyphae
- Racquet hyphae
- Spiral hyphae
- Rhizoids
19
Q
This refers to the frequent cross walls of a hyphae
A
Septate
20
Q
This refers to the irregular interval (of cross walls) of a hyphae
A
Sparsely septate
21
Q
The absence of cross walls of a hyphae
A
Aseptate
22
Q
This elevation is described as furrowed or convoluted
A
Verrucose
23
Q
This elevation is described as slightly raised in the center
A
Umbonate
24
The elevation furrows (and) radiate out from the center
Rugose
25
How many days does it take for a slow grower to grow?
11-21 days
26
How many days does it take for a rapid grower to grow?
5 days or less
27
How many days does it take for an intermediate grower to grow?
6-10 days
28
IDENTIFY: This is nonpigmented or lightly pigmented. And sometimes referred to as moniliaceous
Hyaline
29
IDENTIFY: This is darkly pigmented and melanized. Sometimes referred to as dematiaceous.
Phaeoid
30
This fungus is easy to isolate, and is tan to yellowish
Yeast
31
In phaeoid, the pigmentation is caused by?
melanin
31
This is the characteristic of a fungi that refers to its ability to obtain food by absorbing it from its environment
Saprophytic
32
TRUE OR FALSE: Pigmentation should be seen with a stain
FALSE. It should be seen **without** a stain
33
Its black appearance is brought about by the stain not necessarily by a phaeoid
Gomori methylene
34
In Fontana-Masson, what is the color of the stain if it is a hyaline
pink to red
35
In Fontana-Masson, what is the color of the stain if it is a phaeoid?
brown
36
This texture is described as loose, high aerial mycelium
Cottony
37
This texture is described as high aerial mycelium that appears slightly matted down
Woolly
38
This texture is described as dense, powdery, resembling sugar granules
Granular
38
This texture is described as low aerial mycelium resembling a velvet cloth
Velvety
39
Mold and yeast phase
Dimorphic fungi
39
If the fungi are dimorphic, mold grows in what temperature?
25C to 30C
39
This texture has a smooth surface with no aerial mycelium
Glabrous
40
Both yeast and mold forms in the same culture
Polymorphic Fungi
41
If the fungi are dimorphic, yeast grows in what temperature?
35C to 37C
42
This term refers to asexeual reproduction
Anamorph
43
If the production of spores is endogenous it is termed as ____________, and if it is exogeneous it is _____________
sporangiospore; conidiophore
44
IDENTIFY: Large, usually multiseptate, and club- or spindle- shaped
Macroconidia
45
IDENTIFY: small, unicellular, round elliptical
Microconidia
46
Asexual reproduction results in the formation of _______ following mitosis
conidia
47
Asexual reproduction
is carried out by specialized fruiting structures known as _______________. This also contains genetic material
Conidiogenous cell
48
Two common conidiogenous cells are the:
- Phialides
- Annellides
49
These are vaselike structures that produce phialoconidia
Phialides
50
These are ringed structures that produce annelloconidia
Annellides
51
These conidia are formed by fragmentation of fertile hyphae as opposed to being formed by conidiogenous cell
arthroconidia
52
These are supporting structure and are saclike structure produced at the tip
Sporangiophore
53
Asexual reproduction is characterized by the presence of?
sporangiophores and sporangiospores
54
Produced through the structure sporangium
Asexual spores (sporangiospores)
55
Joining of two compatible nuclei, followed by meiosis.
Sexual reproduction
56
Fungi that reproduce sexually
Teleomorph
57
Asexual forms of the same fungus
Synanomorphs
58
The sexual term (counterpart) of conidia
ascospore
58
The sexual term (counterpart) of sporangiospore
zygospore
59
Sexual and asexual reproduction in mucorales
sexual: Zygospores
asexual: Sporangiospores
59
Subphylum Mucoromycotina. This reproduces asexually (for most clinically significant pathogens
Mucorales
60
Reproduce sexually (ascospores). 50% of all named fungi belong to this phylum
Ascomycota
60
Produce profuse, gray to white, aerial mycelium characterized by the presence of hyaline, sparsely septate hypha
Mucorales
61
This phylum has no mode of sexual reproduction as it is yet to be identified.
Fungi imperfecti or Deuteromycota
61
Reproduce sexually (basidiospores). Its distinct feature is its ability to form clump connections
Basidiomycota
61
Enumerate the different respiratory tract specimens
- Sputum
- Induced sputum
- Tracheal aspirations
- Bronchial washings
- Broncho alveolar lavage
62
Processing of fungi should be done in a (safety issue)?
Class II biological safety cabinet
63
Container used for respiratory tract specimens
sterile & screw-top
64
Media used for respiratory tract specimens
- Nonselective and with antibacterial agents
65
Type of swab for respiratory tract specimens
Dacron swab
65
What is the mucolytic agent for respiratory tract specimens?
N-acetyl-L-cysteine
66
If the respiratory tract specimens are processed within 2 hours, it is stored at?
Room Temperature
67
If there is a delay in processing respiratory tract specimens, it is stored at?
Refrigerated (4°C)
68
Automation used for blood cultures
- BACTEC
- ALERT
- VersaTREK
69
If fungi are dimorphic, this is used to lyse the WBCs and RBCs to get concentrates
Isolator
70
The media used for CSF should have?
no antibacterial or anti-fungal agents
70
Incubation period of blood
30°C for 21 days
71
Preparations for CSF
- Centrifugation
- Filtration
72
Storage for CSF
Room Temperature or 30°C
73
This specimen is to be examined using direct microscopic slide examination
Eye (Corneal Scarpings)
74
This is used as a common identifier of hair, with a UV of >365 nm
Wood lamp
74
Media used for Eye (Corneal Scarpings)
Non-inhibitory
75
Storage for eye (Corneal Scarpings)
Room temperature
76
This is inoculated on fungal medium and incubated at 22° to 30°C
Hair
77
Cleaned with 70% isopropyl alcohol prior to the collection
Skin and nails
78
Scraped from outer edge of surface lesion. KOH wet mount is used to examine this specimen
Skin
79
Scrapings or cuttings. Deeper scrapings for KOH
Nails
80
Use to cut nails into small thin strips
sterile scissors
81
Submitted within 24 hours and transported via swabs
Vaginal sample
82
When using nails as a specimen this is more ideal for inoculating or culturing in a media
cuttings
83
Media used for vaginal sample
Selective and inhibitory
84
Screened for yeasts and incubate at 30° C for 7 days
Vaginal sample
85
Processed immediately
CSF or Urine
86
If urine is clear this is done as well as for quantitative culture
Centrifugation/ centrifuged
87
Storage for urine
< 2 hrs: RT
> 2 hrs: 4°C
88
This specimen is minced, grinded, and homogenized and is incubated at 30°C for 21 days
Tissues
89
If bone marrow is the specimen used, the syringe should be flushed with?
heparin
90
This is the common specimen used to identify yeast and hyphal elements
urine
91
Centrifugation is performed and isolator tubes can be used in processing this specimen
Bone marrow
92
What is the percent of KOH solution used in KOH preparation?
10% to 20% KOH solution
93
This breaks down keratin
10% to 20% KOH solution
94
Samples that can be used for KOH preparation
skin, hair, nails, and tissue
95
Procedure for KOH Preparation:
1. Add _______to sample in slide
2. Cover w/ slip
3. Heat then cool for approx ________
1 drop ; 15 mins
96
Greater breakdown of debris. No heat required
Dimethyl sulfoxide (DMSO)
97
Binds to polysaccharides in chitin walls of fungus
KOH with Calcofluor White
98
The positive for this procedure is fluorescent apple green or blue-white
KOH with Calcofluor White
99
Used to examine CSF
India Ink
100
Positive for yeast using india ink
clear w/ halo (capsule)
101
What is observed in KOH preparation?
Hyphal formation
102
Procedure for India Ink:
1. 1 drop specimen: _____ drop India ink
2. Examine on ________
1 drop; HPO
103
Disadvantages in India Ink
WBCs or air bubbles resemble encapsulated organisms
104
Detection of fungi. Hyphae of molds and yeasts can be readily distinguished
Periodic acid Schiff (PAS) stain
105
Examination of melanin pigment in fungal cell
walls
Masson-Fontana stain
106
Enumerate the different procedure for direct microscopic examination of specimens
1. KOH preparation
2. KOH with calcofluor white
3. India Ink
4. Tissue stains
107
Microscopic examination involves:
- Septate versus sparsely septate hyphae
- Hyaline or phaeoid hyphae
- Fruiting structures
- The types, size, shape, and arrangement of
conidia
108
Kills, preserves and stains organisms
Lactic Acid, phenol and dye in LPCB
109
Positive for tease mount
Blue appearance
110
Involve gently touching a piece of clear tape, sticky side down, to the surface of the colony and then removing it
Cellophane tape preparation
111
Initial isolation of pathogens and saprobes
Sabouraud dextrose agar
111
Composition of Lactophenol cotton blue (LPCB)
Lactic Acid, phenol and dye
112
Tape preparations should be read within _________ and then discarded.
30 minutes
113
An antibiotic agent that inhibits insignificant fungal contaminants
Cycloheximide
114
An antibiotic agent that inhibits bacterial growth
Gentamicin or Chloramphenicol
115
With 5% to 10% Sheep
blood. Enhanced growth of dimorphic fungi
Brain-heart infusion (BHI)
116
Routine procedures performed (katong gi emphasize ni ma'am jo na dili kalimtan)
1. KOH preparation
2. India Ink
3. Germ tube
117
Isolation and presumptive identification of filamentous fungi
Chromogenic agar
118
Allows identification of pathogenic yeast by examining the microscopic morphology of inoculum growth
Cornmeal agar
119
Incubation requirements:
For culture
- Temperature: __________
- Duration: _____________
- Cultures should be examined at least __________
- Temperature: 30°C
- Duration: 21 to 30 days
- Cultures should be examined at least three times weekly
120
Differentiate yeast with their ability to create a
germ tube
Germ tube
121
- Grown with serum or plasma at 35° C
- Ability to form hyphae
- (+) Candida albican
Germ tube
122
Procedure for Germ tube:
1. Add yeast colony to _______ serum
2. Incubate at 35°C for __________
3. Observe under microscope
0.5 ml serum; 2.5-3 hours
123
Reporting for KOH preparation
(+) Presence of Hyphal elements
(-) No hyphal elements
124
Does not appear blue in tease mount because it is darkly pigmented
Phaeoid
