8. Appropriate use of microbiology lab

Question 1

How much time do most microbiological investigations require?

Answer 1

At least 18 hours

Question 2

How many sets of blood cultures should be taken for a seriously ill febrile patient with suspected infective endocarditis?

Answer 2

3

Question 3

In what circumstance might it be difficult to take a cerebrospinal fluid (CSF) specimen collection?

Answer 3

In present or suspected raised intracranial pressure

Question 4

What is the role of the microbiology lab in the hospital environment?

Answer 4

Diagnose infections
Guide treatment
Control HCAIs
Give info for community protection

Question 5

Which stain allows you to see fungal hyphae?

Answer 5

Grocott stain

Question 6

When is the best time to take a blood culture?

Answer 6

Before antibiotic treatment starts

Question 7

What is the optimal time to do serology tests?

Answer 7

3-4 weeks after the infection

Question 8

Which types of microbes grow on enrichment culture?

Answer 8

Fastidious ones

Question 9

What is a selective culture?

Answer 9

Allows one type of organism to grow while suppressing others

Question 10

What is a differential culture?

Answer 10

Plate changes colour due to a metabolic characteristic of the organism

Question 11

What is a chromogenic culture?

Answer 11

Different organisms appear different colours

Question 12

What are the 5 steps in culture?

Answer 12

Innoculation
Incubation
Isolation
Inspection
Identification

Question 13

What circumstance are agar slopes used for?

Answer 13

Long term cultures

Eg. TB

Question 14

What machine can identify the genetic make up of an organism?

Answer 14

MALDITOF

Question 15

Name 2 methods of antibiotic susceptibility testing

Answer 15

Disc diffusion

Antibiotic gradient MIC

Question 16

What technique is used to detect antigens?

Answer 16

ELISA

Question 17

What is the downside of PCR?

Answer 17

Doesn’t distinguish between alive and dead organisms