Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BACTE MIDTERMS > MYCOBACTERIA PT 2 > Flashcards

MYCOBACTERIA PT 2 Flashcards

1
Q

What is the most commonly recommended container for isolation and identification of mycobacteria?

A

sterile, wide-mouth cup with a tightly fitted lid

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

An ________ specimen should be collected on
__ consecutive days

A

early-morning; 3

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

True or false:

  1. If at least 2 out of 3 sputum direct
    smears are positive, then 3 specimens are often
    sufficient to confirm a diagnosis.
  2. However, when none, or only one, of the first three
    sputum smears is positive, additional specimens
    are needed for culture confirmation.
A

True

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

__ to __ ml of sputum produced by a deep cough or inhalation of aerosol

A

5 to 10 ml

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

appear to be more commonly
diagnostic than washing or biopsy; since washing can dilute sample, and biopsy; can have less bacteria

A

Brushings

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

To children who have difficulty producing sputum, what kind of test is recommended?

A

Gastric aspiration

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

_____ should be obtained in the
morning after an overnight fast

A

Gastric aspirates

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

How many specimens should be obtained in gastric aspirates?

A

3 specimens within 3 days

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

In gastric aspiration, what is instilled orally
or via nasogastric tube aspiration? And what amount?

A

Sterile water, 30 to 60 mL

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

What collected specimen is preferred for urine? and at what amount?

A

First morning midstream; 40 ml

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

This specimen is collected to patients with AIDS, who may be at risk for
developing disseminated mycobacterial disease
resulting from Mycobacterium avium complex

A

Stool

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

This specimen is collected for suspected mycobacteremia

A

Blood; in tubes of SPS, heparin & citrate

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

In collecting tissue/body fluids, how many sterile saline should be added to prevent dehydration?

A

10-15 mL

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

Specifically how many sterile saline for each specimen?

  1. CSF
  2. Exudates and pericardial and synovial fluids
  3. Abdominal and chest fluids
A
  1. 2 mL
  2. 3 to 5 mL
  3. 10-15 mL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false:

  1. The purposes of the digestion-decontamination
    is to: to solididy the sample through digestion of the proteinaceous material;
  2. To allow the chemical decontaminating agent to
    contact and kill the non mycobacterial organisms
A

Statement 1 is false because the purpose is to liquefy not solidify

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

This serves as a
digestant and decontaminating agent. What is its’ concentration?

A

Sodium Hydroxide; 2-4%

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

A digestant-decontamination combination of a liquefying agent, NaOH is commonly used. This is a treatment with mucolytic agents that splits mucoprotein.

A

N-Acetyl-L-cysteine

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

Another digestant-decontamination: Zephiran combined with trisodium
phosphate (Z-TSP)

A

Benzalkonium Chloride (Zephiran)

Zephiran (for digestion)
Z-TSP (for decontamination)

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

used to decontaminate
specimens contaminated with Pseudomonas
aeruginosa, such as sputum specimens from
patients with Cystic fibrosis

A

Oxalic acid, 5%

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

In staining (Ziehl-Neelsen and Kinyoun stains), what is the purpose of:

  • carbolfuchsin
  • acid-alcohol
  • methylene blue
A
  • carbolfuchsin: primary stain
  • acid-alcohol: decolorizing agent
  • methylene blue: counterstain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the differenze between the procedure of Ziehl-Neelsen and Kinyoun acid?

A

Ziehl Neelsen: application of heat with carbolfuchsin stain
Kinyoun acid-fast stain: cold stain

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

How do you examine slides for mycobacteria? What objective, fields, and time?

A

x100 OIO for 15 minutes, view minimum of 300 fields

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

The generation time of mycobacteria is longer
than __ hours; M. tuberculosis has the longest
replication time, at __ to __ hours.

A

12 hours
20 to 22 hours

24
Q

Most pathogenic mycobacteria require how many
weeks of incubation?

A

2 to 6 weeks

25
The growth of M. tuberculosis is enhanced by an atmosphere of __ to __ CO2
5% to 10%
26
Mycobacteria require a pH between __ and __
6.5 and 6.8
27
does not grow on media used routinely to isolate mycobacteria and **requires extended incubation (6 to 8 weeks)**
M.genavense
28
What are the **nonselective egg-based media?** (no antibiotics)
1. Lowenstein-Jenses Medium (LJ) 2. Petragnani medium 3. American Thoracic Society (ATS) This all contain dye: Malachite green, prevents gram-positive
29
What are the **selective egg-based media?** (with antibiotics)
1. Gruft modification of LJ 2. Mycobactosel
30
True or false: Selective media that contain antimicrobial agents are sometimes used in combination with nonselective media to increase the isolation of mycobacteria from contaminated specimens.
True
31
This agar-based medium contains 0.1% casein hydrolysate, which improves the recovery of isoniazidresistant strains of M. tuberculosis.
Middlebrook 7H11 medium
32
True or false: Drug susceptibility tests can't be performed on agar-based media without altering drug concentrations
False - it is viable without altering drug concentrations
33
Mycobacterium spp. grow more rapidly in this medium
Liquid Media
34
What are nonselective liquid media used for subculturing stock strains?
Middlebrook 7H9 broth and Dubos Tween albumin
35
Describe the colonies of M.tuberculosis that are seen as rough?
They exhibit a prominent patterned texture referred to as **cording** (curved strands of bacilli)
36
Describe the colonies of Mycobacterium avium complex
- variable appearance - glossy whitish colonies - occurs with smaller translucent colonies
37
What is the growth/recovery rate of a mycobacteria?
3 to 60 days
38
What is the most commonly used biochemical test for the identification of MTB?
The accumulation of **niacin**, detected as **nicotinic acid**
39
Nicotinic acid reacts with cyanogen bromide in the presence of an amine to form a?
yellow-pigmented compound
40
True or false: It is recommended that the Niacin test be done on egg agar cultures 3 to 4 weeks old and with at least 50 colonies
True
41
used for many years to determine an individual’s exposure to M. tuberculosis
Skin test
42
What test has protein extracted and purified from the cell wall of culture-grown M. tuberculosis is used as the antigen? And called as?
Skin testing - Purified Protein Derivative (PPD)
43
During PPD or skin testing, reactivity is read at how many hours?
48 hours (2 days)
44
What size of raised firm area is considered reactive during PPD/Skin Test?
>10mm or larger
45
What can grow on MacConkey agar without crystal violet, whereas most other mycobacteria cannot?
M.fortuitum-chelonae complex
46
In this test, the high salt concentration (5% NaCl) in egg-based media (e.g., LJ) inhibits the growth of most mycobacteria
Sodium Chloride Tolerance
47
in Sodium Chloride Tolerance, which group of mycobacterium spp are exceptions that grow in presence of 5% NaCl?
M.flavescens, M.triviale, and rapidly growing Mycobacterium spp.
48
In Thiopene-2-Carboxylic Acid Hydrazide (T2H) test, what MTB is susceptible to lower concentrations?
M.bovis
49
What color is the indicator of a positive urease test?
pink to red
50
Reduction of colorless potassium tellurite to black metallic tellurium in 3 to 4 days is a characteristic of what MTB?
MAC - Mycobacterium Avium Complex
51
What color does pyrazinamidase produces?
Red pigment
52
In arylsulfatase test, the liberation of phenolphthalein causes a pH change in the presence of sodium bicarbonate, indicated by the formation of what color?
Pink color change
53
What test is most useful in distinguishing M. chelonae, which is generally negative? It produces a rusty brown colonies
Iron Iptake
54
1. The pH indicator, neutral red, is initially bound to Tween 80 and produces what color? 2. After hydrolysis of tween 80, After hydrolysis of Tween 80, neutral red can no longer bind, and it is released, causing a what color?
amber; pink
55
True or false: 1. Mycobacteria are catalase positive. 2. Mycobacteria are coagulase positive.
Statement 1 is the only true
56
In Catalase testing of MTB: 1. The reaction is read after __ minutes, and the resulting column of bubbles is measured. 2. The column size is recorded as greater than or less than __ mm.
5 mins ; 45 mm
57
What test differentiates M. tuberculosis from the scotochromogens and MAC?
Nitrate reduction test

BACTE MIDTERMS (4 decks)

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