15. clinical microbiology Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are general requirements to consider when collecting a specimen for microbiological sampling?

A
  1. collect from diseased area
  2. collect enough for all tests
  3. avoid contamination from other sites
  4. prompt analysis
  5. obtain prior to treatment therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are a few direct methods to identify microbes?

A
  1. microscopy
  2. molecular method testing
  3. bacteriophage typing
  4. immunologic testing
  5. culture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Serology and immunofluorescence are what type of microbe identification methods?

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

Most bacteria are generally cultured, what are a few exceptions that should undergo stain, immunologic, or PCR for analysis?

A
  1. ricketsia
  2. chlamydiae
  3. mycoplasmas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Fungi are best identified with what test method?

A
  1. sabourad dextrose agar culture

2. tests colony morphology, color and dimorphisms

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

What types of slides can be made for organisms to be detected with microscopy?

A
  1. heat-fixed
  2. wet-mounted
  3. chemically fixed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the different types of Monoclonal antibodies?

A
  1. chimeric
  2. humanized
  3. full human
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a chimeric antibody?

A
  1. come from mice that produce antibodies with a human constant region
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a humanized antibody?

A
  1. monoclonal antibody except for the Ag-binding site, which is still mouse derived
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a full human monoclonal antibody?

A
  1. monoclonal antibody that is produced in a mouse from a human genome sequence.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the 6 step process for monoclonal Ab production?

A
  1. mice injected with Ag, to stimulate Ab production
  2. spleen is homogenized; B cells are “free”
  3. B cells are mixed with cancer cells to produce “immortal” hybridomas
  4. placed in specific medium to only allow growth of hybrid cells
  5. hybrid cells proliferate
  6. hybridomas are cultured to increase numbers.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference between direct and indirect fluorescent antibody detection technique?

A
  1. direct: the Ab is fluorescently tagged and binds directly to the Ag ( tests for presence of Ag)
  2. indirect: the fluorescence comes from an Ab that binds to the Ab that was extracted in the serum of the individual ( tests for presence of the Ab)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What methods can be used to detect the presence/absence of a parasite?

A
  1. immunofluorescence
  2. histological staining
  3. microscopy
  4. negative body fluid stain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ribotyping is a commonly used method of identification that works on what method?

A
  1. requires the 16srRNA gene
  2. amplification of rRNA sequence via PCR
  3. use to compare sequence of the protein with others in a large database
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are monoclonal antibodies in general?

A

1.products of hybridoma cells, that allow prolonged lifespan of Ag specific B cells that have been activated

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

What methods are routinely used to identify parasites?

A
  1. blood histology stains
  2. immunofluorescence
  3. negative staining of body fluids
17
Q

What are molecular genetic tests used to identify?

A
  1. comparison of proteins

2. detect nucleic acids

18
Q

What is plasmid fingerprinting?

A
  1. characterizing bacteria based on the number of plasmids and their molecular weight
19
Q

What is sensitivity?

A

the ability of a test to confirm the presence of a disease

20
Q

What is specificity?

A

statistical probability that a person who does not have a disease will show a negative test result

21
Q

What two features are key to proper immunologic test interpretation?

A
  1. test selection and timing of collection
22
Q

What type of test method uses serum antibodies to detect and identify other molecules?

A

serotyping

- differentiates microbes that differ in antigen composition structure

23
Q

Agglutinate

A

formation of clumps or aggregates of particles in an organized fashion

24
Q

Widal test

A

diagnostic test for typhoid fever

25
Q

Latex agglutination tests

A

pregnancy test and viral hemagglutination

26
Q

What type of test will be used to asses antibody titer measures?

A

agglutination test

27
Q

In what two ways can indirect agglutination tests be conducted?

A
  1. Ag coats a bead, and if Ab is present then agglutination will occur
  2. bead coated with the Ab, aggregation will indicate Ag presence
28
Q

Which test uses blood cell lysis or no lysis to determine presence of Ab in the subjects serum?

A

complement fixation test

29
Q

Do you know how the complement fixation test works?

A

Are you sure, be able to walk through it forwards and backwards

30
Q

What is the indicator in an ELISA test?

A

peroxidase enzyme

31
Q

Direct ELISA measures for what?

A

Ag presence in the sample

32
Q

Indirect ELISA measures for waht?

A

Ab presence in the sample, but unable to indicate if the disease is current or from past.

33
Q

What happens if both the Ag and Ab are present and are subjected to an immunoprecipitation test?

A

three regions develop.

  1. is Ab rich region and low Ag
  2. Ag rich region with low Ab
  3. proper mix of Ab-Ag that bind and precipitate out of solution in between the other two layers