DX of Bacterial and Fungal Infections

Question 1

Choice of diagnostic methods depends on what 2 things?

Answer 1

1. Type of infection

2. Availability of tests

Question 2

What are 4 ways to ID agent?

Answer 2

1. Direct detection of agent (Microscope, stain)
2. Isolate and ID
3. Direct detection of Ag, toxins (ELISA)
4. PCR

Question 3

What is a humoral immune response?

Answer 3

Detect Ab to infectious agent

Question 4

Should specimen collection be done before antimicrobial therapy?

Answer 4

Yes

Question 5

What are 2 bacterial and fungal cultures?

Answer 5

Liquid (Broth media) and Solid (Agar media)

Question 6

What is the latest developmental method in ID of bacteria?

Answer 6

MALDI-TOF

Question 7

What are 3 ways o interpret culture results?

Answer 7

1. Accept result
2. Don’t accept
3. Need further info or testing

Question 8

What is PCR used for?

Answer 8

ID of isolates

Question 9

What are 3 direct tests for microbial components?

Answer 9

1. Antigen detection: Use Ab reagents to detect Ag
2. Chemical detection
3. Biological detection

Question 10

What is an antibody titer?

Answer 10

Measurement of antibody level (quantity)

Expressed as reciprocal of highest dilution of serum that positively reacts in specific tests

Question 11

What is a seroconversion?

Answer 11

Ab development after exposure to pathogen or Ag

Question 12

What are paired serum titers?

Answer 12

Compare acute and convalescent phase samples

A four fold increase in serum titers is indicative of infection