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Flashcards in Clinical Microbiology Deck (68):
1

What is the definition of acute phase?

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

2

What are the general guidelines to collecting specimens?

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

3

what are techniques that limit the contamination from normal flora?

-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

4

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

True.

5

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

False

6

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

Hematoxylin

7

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

Eosin

8

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

Romanowsky Stain

9

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

Diff- Quik

10

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

b. Gram stain

11

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

c. Acid fast stain

12

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

E. A and B

- Leishman and Trichrome are parasite stains

13

Which of the following are examples of agar culture options?

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

d. All the above

14

What are the two different options for broth cultures?

Nutrient Broth
Enrichment Broth

15

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. Eosin methylene blue agar

16

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

MacConkey Agar (MAC)

17

Mannitol Salt Agar (MSA)

-Selective for gram-positive
-Mannitol Fermentation

18

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

CLED agar : Cysteine lactose electrolyte deficient

19

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

c. Can help identify bacteria type

20

Which biochemical test for bacteria ID breaks down hydrogen peroxide?

Catalase

21

Coagulase

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

22

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

Maltose fermentation test
Capsule stain

23

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

ID test strips/plates

24

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

Urine paddle: UTI culture paddles

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