(2) Collection, Handling, Processing of Clinical Mycology Specimens Flashcards
(82 cards)
1
Q
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Enumerate the Specimens to revcover fungi
A
- Hair, skin, and nail scrapings
- Respiratory tract secretion
- Cerebrospinal fluid (csf)
- Blood
- Vaginal secretion
- Urine
- Tissue, bone marrow, and sterile body fluid
2
Q
Specimen to recover fungi
Some of the most common specimens used for diagnostic mycology
A
Hair, skin, and nail scrapings
3
Q
Specimen to recover fungi
They are commonly used to detect dermatophytes, which are keratin-loving fungi.
A
Hair, skin, and nail scrapings
4
Q
Specimen to recover fungi
Hair samples are collected through ____, and placed on a glass slide,or if being transferred, place it initially on a paper or envelope
A
plucking
5
Q
Specimen to recover fungi
Skin scrapings are collected with the use of a sterile blade wherein the site of collection is first cleaned with a ____ to remove normal flora, and then followed by scraping the skin.
A
70% alcohol
6
Q
Specimen to recover fungi
When the skin has lesions, sample is collected
from?
A
the edge of the lesion where the most active fungi are located
7
Q
Specimen to recover fungi
how nails are collected?
A
nail clippers
Preferably, the nails with lesions should be collected
8
Q
Specimen to recover fungi
Used for detecting systemic mycoses which mainly attacks lungs
A
Respiratory tract secretion
9
Q
Specimen to recover fungi
- It may involve sputum, bronchial washing, bronchoalveolar lavage, and tracheal aspirates.
- They are considered as non-sterile and may consist of normal flora apart from the target causative aent.
A
Respiratory tract secretion
10
Q
Specimen to recover fungi - Respiratory
To prevent interferences from the normal flora, culture media containing inhibitors, specifically?
A
antibiotics
11
Q
Specimen to recover fungi
- Collected by physicians through spinal or lumbar tap.
- It is considered as a sterile specimen, and no normal flora are present within the samples. (culture without inhibitors can be used)
A
Cerebrospinal fluid (CSF)
used
12
Q
Specimen to recover fungi
what portion of CSF samples are tested?
A
Sediment part
13
Q
Specimen to recover fungi
how sediment part of CSF isolated?
A
- First Method: membrane filter is attached in the syringe and is used to separate the sediment
- Second Method: centrifugation
the liquid portion should not be thrown, and should be kept at room temperature
14
Q
Specimen to recover fungi
Also mainly used to detect systemic fungi
A
BLOOD
15
Q
Specimen to recover fungi
how is blood samples examined?
A
automated machines
most common automated machines used in the laboratory are BACTEC, VERSATEK, and Bact-ALERT - mainly used to detect yeast
16
Q
Specimen to recover fungi
- Commonly used in detecting infections mainly caused by the Candida species.
- Samples are collected through a cotton swab and are processed immediately as it can dry out which disintegrates the fungi.
ASAP Procesing
A
Vaginal Secretion
17
Q
Specimen to recover fungi
- Processed immediately, within 24 hours, upon receipt.
- The sediment is also the portion examined and may be collected through centrifugation
A
Urine
18
Q
Specimen to recover fungi
- Processed immediately upon receipt.
- Time of collection is noted since the optimum time of recovery of fungi is within an hour after collection
A
Tissue, Bone marrow, and sterile body fluids
19
Q
Specimen to recover fungi
Samples should be submitted in the laboratory and
processed as soon as possible.
BUT WHAT IF THERE IS A DELAY? what can u do
A
Refrigeration for short time, max of 24 hours
- EXCEPT for five specimens— hair, nail, skin, blood, and CSF. Stored at RT or incubaterd at 30 ‘C
- When storing exceeds 24 hours, samples should be recollected.
quit yo job
20
Q
Enumerate the methodologies for fungal infection
A
- Microscopic Examination (Direct and Staining)
- Fungal Culture
- Biochemical Tests
- Serology-Antigen Detection Tests
21
Q
- One of the routine analysis in the laboratory
- Provides rapid diagnosis of some fungal infections. HOWEVER just the presence or absence of fungi
- Look for fungal structures
A
Microscopic Examination
22
Q
T or F
- Direct examination require STAINS to be added
- Samples are examined in HIGH LIGHT
A
Both F
- Does not require stain - COLORLESS
- Examined under low light
23
Q
Direct Examination
- Examination is done in a natural environment.
- Good for examining YEASTS.
- Only incorporates saline.
A
Saline Wet Mount
structure.
Report as either “positive” or “negative” for fungal
24
Q
Direct Examination
Commonly done on skin scrapings, hair, nails, sputum, and
vaginal secretions.
A
Potassium Hydroxide (KOH) Preparation
25
# Direct Examination
What is the function of KOH preparation?
**softening, digesting, and clearing cellular debris**, such as tissue cells and mucous, to prevent
interferences
26
# Direct examination
what percentage of KOH are used for routine and hard exterior
1. 10% KOH
2. 20% KOH
27
# Direct Examination
KOH preparation shoud be place in a petri dish together with?
**Damp piece of filter paper**
to prevent speciment from drying out
| Report as either **“positive”** or **“negative”** for fungal
28
# Direct Examination
Aids in the visualization of diagnostic features of fungi, especially those that are **dimorphic**
Stains
29
Enumerate all the stains
1. Lactophenol Cotton Blue (LPCB)
2. Calcofluor White
3. India ink
4. Giemsa or Wright Stain
5. Gram Stain for Yeasts
6. Periodic Acid Schiff (PAS)
7. Gomori Methenamine Silver Stain
30
# Stains
It is one of the most common stains used in the laboratory during routine tests
Lactophenol Cotton Blue (LPCB)
31
# Stains
Enumeate the component of LPCB
- Lactic Acid
- Phenol
- Cotton Blue (aman stain)
32
# Stains - LPCB
used as a preservative for LPCB
Lactic acid
33
# Stains
Killing or removal of non-fungle element for LPCB
Phenol
34
# Stains
the actual stain for LPCB
Cotton blue or Aman stain
35
# Stains
* Fluorescent dye that binds with the chitin in the fungal cell wall.
* Requires a fluorescence microscope
Calcofluor White
36
# Stains
what is the appearance of Calcfluor white stained fungi under a micrscope
appear white to blue to green fluorescence
37
# Stains
what can be mixed with Calcofluor white for rapid diagnosis of fungal structure
KOH
38
# stains
A negative or an indirect stain used
for the detection of the CAPSULE of
**Cryptococcus neoformans** in CSF
specimen
India ink
39
# Stains
what is the causative agent of meningitis, and give the stain for the detection
- Cryptococcus neoformans
- India ink
40
# Stains
what will be the appearance of capsule with india ink stains
Appear as clear halo against a black background
41
# Stains
Used for the examination of bone marrow or peripheral blood sample
Giemsa or Wright stain
42
# Stain
what does the Giemsa stain detect?
**Histoplasma capsulatum**—a type of systemic fungi
43
# Stain
* Routine stain for the detection of bacteria but can also detect
fungi if present in the specimen.
* Yeast stains as gram (+) which is indicated by a purple
color.
Gram Stain for Yeasts
44
# Stain
* Stains the polysaccharide in the cell walls of fungi
* Fungi stain pink-red with blue nuclei
* Most commonly used for tissue samples collected through biopsy
Periodic Acid Schiff (PAS)
45
# Stain
Silver nitrate outlines fungi in black due to the silver precipitating on the fungal cell wall.
Gomori Methenamine Silver Stain
46
# Stain
what are the staining color of the internal parts of the hypae and background for Gomori stain
- Deep rose to black
- Light green
47
Considered to be the GOLD STANDARD for the diagnosis of fungal infection
it detects specific GENUS and SPP
Fungal Culture
48
TOF - Fungal Culture
Advantage of yielding the SPECIFIC ETIOLOGICAL AGENT through fungal culture—in vitro using artificial media
T
49
# Fungal Culture Considerations
1. Incubation temp (most fungal)
2. Growth for most fungi
3. Incubation temp for Dimorphic
4. Growth for rapid growers
5. Cultures maintenance
a. 37 ‘C
b. 25 ‘C to 30 ‘C.
c. 1 to 2 weeks
d. 21 to 30 days
e. high-humidity environment
1. B
2. D
3. A
4. C
5. E
50
# Culture media
what media are used for anti-fungal agent which removes fungal
contaminants
Media with and without CYCLOHEXAMIDE
51
# Culture media
What media are used for required for samples with normal flora or
non-sterile samples
with and without an ANTIBACTERIAL AGENT
52
# Culture media
Medium may be place in a??????
plate or tube
| plated media is preffered offers a larger surface for growth
53
What are the types of primary culture media
1. Primary or General Purpose Media
2. Differential Test Medium
54
Contains nutrients necessary for the growth of a wide variety of fungi—making it a non-selective medium
Primary or General Purpose Media
55
what is the most commonly used general media
1. **SDA** - mold culture (It can also inhibit the growth of bacteria due to its acidic pH)
2. **BHIA** - for pathogenic fungi, specifically, yeast.
56
# Identify what Primary Media
- **General media**, recommended for
most studies.
- Has an **acidic pH at 5.6** that inhibits most bacteria and supports the growth of majority of fungi
Sabouraud’s
Dextrose
Agar (SDA)
57
# Identify what Primary Media
- Primary recovery of **saprobic and pathogenic fungi.**
- Provides a rich medium for **bacteria, yeast, and pathogenic fung**i.
Brain Heart
Infusion Agar
(BHIA)
58
# Identify what Primary Media
- Primary recovery of pathogenic fungi exclusive of **dermatophytes**.
- The agar provides a rich medium for **yeast and pathogenic fung**i.
BHIA with Antibiotics
59
# Identify what Primary Media
- Recovery of fungi from **blood**
- Enhances the recovery of **yeasts in blood**
BHI Biphasic Blood Culture
Bottle
60
# Identify what Primary Media
- Isolation and presumptive identification of **yeast and filamentous fungi.**
- contains substrates that react with
enzymes produced by different organisms that result in the production of characteristic **color changes**.
Chromogenic
Agar
61
# Identify what Primary Media
- Primary recovery of **dermatophytes**; recommended as *screening medium*
- **Dermatophytes** produce alkaline metabolites, which raise the pH and change the medium from red to yellow
Dermatophyte Test Medium
62
# Identify what Primary Media
- Primary recovery of pathogenic fungi exclusive of **dermatophytes**
- Examine plates for growth. Chloramphenicol inhibits bacterial growth.
Inhibitory Mold Agar
63
# Identify what Primary Media
- Primary recovery of **saprobic and pathogenic fungi**
- Growth is enhanced by a pH alkaline reaction of fungus. **Chloramphenicol and antibiotics** inhibit the growth of bacteria and
nonpathogenic fungi
Potato Flake
Agar
64
# Identify what Primary Media
- Primary recovery of **dermatophytes**
- Inhibits **bacteria and saprophytic fung**i
Mycosel
65
# Identify what Primary Media
- Primary recovery of **saprobic and pathogenic fungi**
- Isolates and enhances growth of pathogenic fungi
Sabouraud’s Dextrose with Brain Heart Infusion (SABHI)
66
# Identify what Primary Media
- Primary recovery of **pathogenic fungi exclusive of dermatophytes**
- Enhances the recovery of **Blastomyces and Histoplasma** capsulatum from contaminated
specimens
Yeast Extract Phosphate Agar
67
This medium used to enhance pigment development, conidia production, and mold-to-yeast phase transition of dimorphic fungi
Differential Test Medium
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It is able to differentiate species as it is a selective media which allows the growth of a specific fungi, or a common group of fungi
Differential Test Medium
69
# Identify what Differential Test Medium
Detection of **ascospores** in
ascosporogenous yeasts
Ascospore Agar
70
# Identify what Differential Test Medium
Identification of **Cryptococcus, Trichosporon, and Rhodotorula** species
Christensen’s Urea
Agar
71
# Identify what Differential Test Medium
Identification of **Candida albicans** by chlamydospore production; identification of C. albicans by microscopic morphology
Cornmeal Agar with Tween 80 and Trypan Blue
72
# Identify what Differential Test Medium
Conversion of the **dimorphic
fungus Blastomyces species**from
mold to yeast form
Cottonseed Conversion Agar
73
# Identify what Differential Test Medium
Differential identification of
**Aspergillus species**
Czapek’s Agar
74
# Identify what Differential Test Medium
Identification of Cryptococcus **neoformans** and Cryptococcus **gattii**
Niger Seed Agar
(Birdseed Agar)
75
# Identify what Differential Test Medium
Detection of nitrate reduction to confirm **Cryptococcus species**
Nitrate Reduction Medium
76
# Identify what Differential Test Medium
Demonstration of pigment
production by **Trichophyton rubrum;**
preparation of microslide vultures and **sporulation of dermatophytes**
Potato Dextrose Agar
77
# Identify what Differential Test Medium
Identification of **Microsporum audouinii**
Rice Medium
78
# Identify what Differential Test Medium
Identification of **Trichophyton species**
Trichophyton Agars 1-7
79
# Identify what Differential Test Medium
Detection of **Cryptococcus species**; differentiate Trichophyton mentagrophytes from Trichophyton rubrum; detection of **Trichosporon species**
Urea Agar
80
# Identify what Differential Test Medium
Identification of **yeasts** by
determining *fermentation*
Yeast Fermentation Broth
81
# Identify what Differential Test Medium
Identification of **yeasts** by
determining *carbohydrate assimilation*
Yeast Nitrogen-base Agar
82
