Antibiotic Susceptibility

Question 1

the antimicrobial agent in question
may not be an appropriate choice for treating the infection
caused by the bacterial isolate tested

Answer 1

RESISTANT

Question 2

In the category Intermediate, what are the possibilities to consider? Give one.

Answer 2

1. utility of the antimicrobial agent in body sites where it may be concentrated (e.g., the
   urinary tract) or if high concentrations of the drug are used
2. The antimicrobial agent may still be effective against the tested isolate but possibly less
   so than against a susceptible isolate
3. As an interpretive safety margin to prevent relatively small changes in test results from
   leading to major swings in interpretive category (e.g., resistant to susceptible or vice
   versa)

Question 3

the antimicrobial agent in question may be an appropriate choice for
treating the infection caused by the bacterial isolate tested.

Answer 3

SUSCEPTIBLE

Question 4

Instead of using reflected light, We use ______ to improve the accuracy of tests

Answer 4

TRANSMITTED LIGHT

Question 5

What are the tests that uses Transmitted light?

Answer 5

• penicillinase-resistant penicillins
• linezolid
• vancomycin when testing staphylococci
• vancomycin when testing enterococci

Question 6

For plates containing blood, it is important
to read the zone
of inhibition of _____ and not the zone
of inhibition of _______.

Answer 6

growth; hemolysis

Question 7

What do we use in measuring the inhibition zone?

Answer 7

ruler or calipers

Question 8

The lawn grown must be?

Answer 8

confluent or almost confluent

Question 9

Plates are placed a few inches above a black, nonreflecting
surface, and zones are examined from the ____ (agar
side) of the plate ________

Answer 9

backside; illuminated with reflected light

Question 10

What agar plate is used in inoculation and incubation?

Answer 10

Mueller-HInton agar plate

Question 11

It is used for testing streptococci that do not grow adequately on unsupplemented Mueller-Hinton agar

Answer 11

Mueller-Hinton agar with 5% sheep blood

Question 12

The disks are pressed firmly to ensure contact with the agar. Within __ minutes of
disk placement, plates are inverted and placed in a ___ ambient air incubator for __
to __ hours.

Answer 12

• 15
• 35°C
• 16 to 18

Question 13

From what institute are being followed by most clinical laboratories in protocols?

Answer 13

Clinical and Laboratory Standard Institute

Question 14

In Disc storage, Long term storage: ___or below in a ______

Answer 14

-20°C ; non-frost free freezer

Question 15

A working supply of disks can be stored in a refrigerator at ____ for at least _____.

Answer 15

2°C to 8°C ; 1 week

Question 16

Disks should always be stored in a ________

Answer 16

tightly sealed container with desiccant

Question 17

The container should be allowed to warm to room temperature before it is opened to
_______

Answer 17

prevent condensation

Question 18

Disk diffusion testing is also commonly known as?

Answer 18

Kirby Bauer test

Question 19

A _______ standardized suspension of bacteria is swabbed

Answer 19

McFarland 0.5

Question 20

The antimicrobial agents that are chosen for testing against a particular
bacterial isolate are referred to as the ?

Answer 20

antimicrobial battery or panel

Question 21

Matching turbidity using the unaided eye is facilitated by holding the bacterial suspension and McFarland tubes ______ and viewing
them against a ______.

Answer 21

side by side; black-lined background

Question 22

Once standardized, the inoculum suspensions should be used within _________.

Answer 22

15 minutes of preparation

Question 23

If the bacterial suspension initially does not match the standard’s turbidity, the suspension may be _______________________.

Answer 23

diluted or supplemented with more organisms as needed