Clinical Microbiology Flashcards

(68 cards)

1
Q

What is the definition of acute phase?

A

Symptoms that are very pronounced and there is typically a strong reaction of immune system and active replication/multiplication of the pathogen.

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

What are the general guidelines to collecting specimens?

A
  1. Use of aseptic techniques to avoid sample contamination
  2. Best to collect samples that will be specific for your infectious pathogen
  3. Specimens should be taken before antibiotics/treatments are started during the acute phase of the disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are techniques that limit the contamination from normal flora?

A
  • Remove fluid specimen from inside the intact pustule to avoid contamination from bacteria on healthy skin
  • Remove urine directly from bladder with sterile syringe to avoid contamination from lower urinary tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

True/False. Cystocentesis is preferred specimen for UTI diagnostics to avoid contamination from lower urinary tract.

A

True.

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

True/False. All specimen should be stored in a refrigerator (4 degrees C) prior to diagnostic testing.

A

False

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

The following stains acidic or negative charged components purple and is considered to be a basic stain.

A

Hematoxylin

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

___ is an acidic stain that stains basic or positively charged components red/pink.

A

Eosin

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

Which staining method can identify sample abnormalities, usually with blood, in bacterial and parasitic infections?

A

Romanowsky Stain

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

What is a modification of the Giemsa stain, fast to use, and can be used to stain multiple specimen types?

A

Diff- Quik

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

Which stain is typically used to differentiate between gram-negative and gram-positive bacteria in tissues or isolated cultures?

a. H and E stain
b. Gram stain
c. Romanowsky stain
d. Endospore stain

A

b. Gram stain

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

Which stain is used to stain organisms with impenetrable cell walls, such as Mycobacterium and Cryptosporidium?

a. Capsule stain
b. Endospore stain
c. Acid fast stain
d. Fungal stains

A

c. Acid fast stain

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

Which of the following are examples of fungal stains?

a. PAS
b. GMS
c. Leishman
d. Trichrome
E. A and B
F. B and C

A

E. A and B

  • Leishman and Trichrome are parasite stains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which of the following are examples of agar culture options?

a. Nutrient media
b. Selective media
c. Differential media
d. All the above

A

d. All the above

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

What are the two different options for broth cultures?

A

Nutrient Broth

Enrichment Broth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following select for gram-negative organisms?

a. Eosin methylene blue agar
b. Sabouraud dextrose agar
c. Phenyethyl alcohol agar
d. Columbia CNA agar

A

a. Eosin methylene blue agar

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

Which agar is selective for gram-negative organisms and ferments lactose?

A

MacConkey Agar (MAC)

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

Mannitol Salt Agar (MSA)

A
  • Selective for gram-positive

- Mannitol Fermentation

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

_____ agar supports the growth of common urinary pathogens and is a lactose fermenter.

A

CLED agar : Cysteine lactose electrolyte deficient

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

What is a diagnostic advantage of differential media vs. nutrient media?

a. It allows most types of bacteria to grow
b. Inhibits growth of parasites
c. Can help identify bacteria type
d. Agar plates are pretty cool

A

c. Can help identify bacteria type

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

Which biochemical test for bacteria ID breaks down hydrogen peroxide?

A

Catalase

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

Coagulase

A

Biochemical test for bacterial ID that causes fibrin in blood to clot

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

Which two techniques are used to identify gram-negative bacterial pathogens?

A

Maltose fermentation test

Capsule stain

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

Which test usually generates a unique code of results for identification?

A

ID test strips/plates

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

This test has a paddle with 2 sides: one is selective EMB media for gram-negative bacteria and the other is non-selective CLED media

A

Urine paddle: UTI culture paddles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Antigens are molecules: a. Made by the immune system b. That trigger a host immune response c. That help the immune system recognize "self" d. All the above
b. That trigger a host immune response
26
What are immunochemical tests?
They detect pathogen-specific immune responses to detect and ID pathogens
27
What are common specimens for antibodies?
IgG: blood, and tissue fluids IgM: blood
28
When should you collect samples to obtain an accurate immunochemical diagnostic test?
- Collect at the acute phase | - Collect again 10-14 days after infetion
29
Which quantitative test is specific for antigen or antibody detection?
ELISA
30
True/False. The ELISA test detects immune response to viruses, parasites, bacteria or fungi and is highly sensitive and specific.
True.
31
The ___ test is an immunochromatographic assay available for antigen or antibody detection of bacteria, viruses, and parasites and can measure several infectious diseases in one test.
IDEXX SNAP tests
32
What is the definition of agglutination?
Particles that clump together (Antibody and its antigen interacting)
33
What are immunological- based diagnostics?
Tests that detect specific antigen or antibodies from a patient specimen that has either a viruses, parasite, bacteria or fungi
34
Indirect Agglutination
Beads are used to enhance visualization of an antigen or antibody.
35
What are the advantages of immunochemical tests?
- ID pathogen when the pathogen can't be cultured - Have high sensitivity and specificity - Mid to high-volume testing possible
36
What are the disadvantages of immunochemical tests?
- Detection of antibody may not indicate active infection - Antibody may not be detected - Antibodies can detect more than 1 pathogen
37
True/False. The MALDI-TOF is a mass spectrometry that detects viral pathogens.
False. MALDI-TOF detects bacterial or fungal pathogens
38
What are the advantages of the MALDI-TOF?
- Rapid ID - High throughput - Can ID bacteria/ fungi
39
What does PCR (Polymerase Chain Reaction) do? a. Degrades antibodies b. Degrades antigens c. Amplifies proteins d. Amplifies nucleic acids
d. Amplifies nucleic acids
40
_____ detect nucleic acids from multiple viruses, bacteria, fungi, and parasite species in a single sample.
Multiplex PCR or Microarrays
41
True/False. Real- time PCR is used highly for bacteria identification and the amount of the bacteria within a specimen (quantitative)
False. It is highly used for VIRUS identification and the amount of VIRUS in a specimen
42
_____ is a pathogen-specific sequence amplification of nucleic acid and measurement.
Real-time PCR
43
Which of the following techniques is faster than culture based methods and requires a pure culture? a. Multiplex PCR b. Microarray c. MALDI-TOF d. All the above
c. MALDI-TOF
44
Which techniques are used for phenotypic diagnostics of bacteria and fungi?
- Gross examination - Cytology - Culture-based methods
45
Which of the following are Immunochemical/serological tests used to detect bacteria and fungi? a. ELISA b. SNAP test c. Agglutination tests d. All the above
d. All the above
46
Which Molecular Diagnostic tests are used to detect bacteria and fungi?
Microarrays MALDI-TOF PCR techniques Real-Time PCR
47
True/False. The same Molecular diagnostics tests that were used to detect bacteria and fungi are used to detect viruses.
True.
48
What immunochemical/ serological tests are used to diagnose viruses?
ELISA SNAP tests Immunofluorescence Agglutination tests
49
True/False. Culture based methods are used for clinical diagnostics of parasites.
Flase. They are NOT used for clinical diagnostics of parasites.
50
True/False. Culture based methods and electron microscopy/mass spectrometry are not used for clinical diagnostics of viruses.
True.
51
A fecal specimen was taken from a cat with a suspected viral respiratory infection. Multiplex PCR did not identify any virus from the fecal specimen. What is the likely explanation for the lack of pathogen diagnosis?
The wrong specimen was collected
52
A dog has symptoms of a skin infection. To avoid normal flora contamination of the specimen what method of specimen collection is preferred?
Collection of liquid from inside an intact pustule
53
A specimen was collected an the clinician wants a quick diagnosis of a viral infection but there are several viruses that produce the same symptoms. What diagnostic test would be most likely to provide a quick diagnosis for pathogen ID? a. Culture b. ELISA to detect antigen-specific IgG antibody c. Agglutination to detect virus-specific IgG d. Multiplex PCR
d. Multiplex PCR
54
What is a common histopathological stain used to stain tissue specimens?
H & E stain
55
Tue/False. A cat has symptoms of an intestinal infection. To determine if the infection is due to a parasite, a fecal sedimentation test, followed by cytology was performed. No eggs were detected. Based on this result the clinician can rule out parasite infection.
False
56
Urine paddle tests use what method to diagnose urinary tract infections? a. Microarray b. Antibiotic susceptibility testing using real time PCR c. MALDI- TOF- MS d. Culture using differential media
d. Culture using differential media
57
How would you collect a sample for a bacterial skin infection?
- Remove fluid specimen from inside the intact pustule | - Avoid contamination from bacteria on healthy skin
58
What are examples of specimens used to detect for parasite infections?
``` Feces Vomit Sputum Bood Muscle Biopsy Skin Scraping Urine ```
59
Swabs from the nasal/tracheal/sputum/eye, feces, blood, tissue/organs are all examples of common specimens for ___ infections.
Viral
60
What is a common tissue stain used to identify bacteria, fungi, parasites, and viral infections?
H & E stain
61
True/False. Viruses and parasites are cultured for diagnostics.
False. Only bacteria and fungi are cultured for diagnostics, parasites and viruses are slow to grow and therefore difficult to culture
62
Which of the following is important to use for the growth of a suspected pathogen type? a. Nutrient Media b. Selective Media c. Differential Media d. Enrichment media
b. Selective Media
63
Which broth increases the number of a specific bacterial type and inhibits the growth of others?
Enrichment broth
64
Which selective media is used to select for gram-positive organisms? a. EMB agar b. TSA agar c. PEA agar d. MH agar
c. PEA agar
65
What selective media is used to select for fungi and inhibits bacterial growth at a low pH?
SabDex Agar
66
___ agar is a selective media used to detect for gram- negative organisms.
EMB agar
67
Which of the following is a non selective differential media involved with hemolysis? a. Blood agar b. MacConkey Agar c. Mannitol Salt agar d. CLED agar
a. Blood agar
68
Urease
Biochemical test for bacterial ID that hydrolyses urea