previous exam questions Test 1

Question 1

A Mc Farland standard of 0.5 corresponds to a bacterial count of:

Answer 1

1.5 x 10(8) cfu/ml

Question 2

The mode of action of erythromycin and azithromycin is:

Answer 2

inhibition of protein synthesis

Question 3

It is not necessary to perform quality control on user prepared MacConkey plates because it is exempt.
false or true

Answer 3

false

Question 4

The spectrum of activity for aminoglycosides is:

Answer 4

aerobic gram positive and gram negative bacteria

Question 5

aerobic gram positive and gram negative bacteria

true or false

Answer 5

true

Question 6

Supplemental testing of Enterococcus spp.for detection of high level resistance to which class of antimicrobials would demonstrate if synergy with ampicillin is possible?

Answer 6

aminoglycosides

Question 7

All of the following antimicrobials are usually effective against gram negative bacteria except:

Answer 7

vancomycin

Question 8

Growth of Enterococcus faecalis on a vancomycin agar screen plate would indicate that the organism is

Answer 8

resistant to vancomycin

Question 9

An isolate of E. coli was found to be ESBL positive, as a result it should be reported as resistant to:
Aminoglycosides
Vancomycin
Levofloxacin
Cephalosporins

Answer 9

Cephalosporins

Question 10

The use of ATCC reference organisms when performing quality control on established procedures will confirm the following:

Answer 10

Validity and reliability

Question 11

This test uses the patient's own serum and can be used to monitor antimicrobic therapy as well as the effects of antibodies and complement.
Disk diffusion
SBC (SBT)
MIC (MBC)
Beta- lactamase

Answer 11

SBC(SBT)

Question 12

Providing detailed instruction to nurses for proper specimen collection will effect this area of Quality Assessment:
Preanalytical
Postanalytical
Analytical
Continuous Daily Monitoring

Answer 12

Preanalytical

Question 13

A large disk diffusion zone size will correspond to a low MIC value.
true or false

Answer 13

true

Question 14

The action of this antimicrobial in the class of Fluoroquinolones is generally bacteriocidal
Levofloxacin
Vancomycin
Cephazolin
Erythromycin

Answer 14

Levofloxacin

Question 15

When performing routine AST quality control, after the initial 20 day testing period, all labs are required to test their systems
weekly 
daily 
monthly
only when new lot numbers are received

Answer 15

weekly

Question 16

Reference bacterial organisms are available through which of the following sources?
CLIA
ATCC
CLSI
TQM

Answer 16

ATCC

Question 17

Antimicrobial resistance resulting from the normal genetic, structural, or physiologic state of a microorganism is defined as

Answer 17

intrinsic

Question 18

Match the term on the left with the best answer on the right.
beta-lactamase inhibitor Erythromycin

glycopeptide Private certifying agency

macrolide Highest serum
antimicrobial level

CAP antifungal drug
CLSI Imipenem
peak specimen Tazobactam
Beta lactam Carbapenem vancomycin
Fluconazole provide laboratory
AST guidelines

Answer 18

Tazobactam
vancomycin
Erythromycin
Private certifying agency
Provides laboratory AST guidelines
Highest serum antimicrobial level
Imipenem
antifungal drug

Question 19

Which of the following will define test performance, reagent preparation, quality control and results reporting as well as display signature by the microbiology supervisor?
Patient reports
Q-Probes
Benchmarks
Standard operating procedure manual

Answer 19

Standard operating procedure manual

Question 20

Which bacterial combinations represent the most appropriate quality control organisms when testing a new lot number of catalase test reagent.

Streptococcus agalactiae and Steptococcus pyogenes
Staphylococcus aureus and Streptococcus pyogenes
Staphylococcus aureus and Staphylococcus saprophyticus
Staphylococcus aureus and Staphylococcus epidermidis

Answer 20

Staphylococcus aureus and Streptococcus pyogenes

Question 21

Which of the following is not an example of intrinsic antibiotic resistance?
Klebsiella vs. ampicillin
Staphylocococcus vs. oxacillin
E. coli vs. vancomycin
Pseudomonas vs. trimethorprim and sulfonamides

Answer 21

Staphylocococcus vs. oxacillin

Question 22

A Mueller Hinton Agar with a depth of 3.5 mm will result in zone sizes that are falsely resistant.
true or false

Answer 22

false

Question 23

In recording the results of a microdilution tray, you notice a slight haze is present in all the trimethoprim-sulfa wells. You would the record the result as
Resistant
Susceptible
Intermediate
Invalid

Answer 23

Susceptible

Question 24

Preanalytical instructions to patient providers in clinics should indicate that which specimen may be refrigerated?
Sputum
Urine
CSF
Urogenital swab

Answer 24

urine

Question 25

``` When performing disk diffusion QC, only one disk out of twelve is out of range. What is the most likely explanation? Inoculum is too light Bad disk Inoculum is too heavy Mixed culture ```

Answer 25

bad disk

Question 26

Panic values should be called immediately to the first available health care worker. true or false

Answer 26

false

Question 27

Quality Assurance is associated with those external activities that ensure positive patient outcomes. true or false

Answer 27

true

Question 28

Microbiology turnaround time can be defined as the elapsed time between Specimen receipt in the lab and reporting of final results Specimen collection and reporting of final results Specimen collection and reporting of preliminary gram stain results Specimen receipt in the lab and initial culture set up.

Answer 28

Specimen receipt in the lab and reporting of final results

Question 29

appropriate organisms to use when performing QC on a new lot of API 20E test systems would be: Enterococcus sp., E. coli and Staphylocccus sp. Klebsiella sp., Haemophilus sp and Enterococcus sp. Pseudomonas sp., E. coli, and Neisseria spp. E. coli, Klebsiella pneumoniae, Proteus mirabilis

Answer 29

E. coli, Klebsiella pneumoniae, Proteus mirabilis

Question 30

Daily review by the Microbiology supervisor of AST results that have been reported is an analytic function. true or false

Answer 30

false

Question 31

An isolate of Staph aureus is determined to be resistant to Linezolid by MIC method. This antimicrobial (Linezolid) is the most appropriate for treatment. true or false

Answer 31

false

Question 32

Disk diffusion testing was performed on an isolate of Pseudomonas aeruginosa from a urine culture. Numerous colonies were observed within the zone of this antimicrobial. What is the most probable cause? Media was too thick Media was too thin Inoculum had too many organisms (too heavy) Resistant mutants

Answer 32

resistant mutants

Question 33

Most antimicrobials are cleared by which organ?

Answer 33

liver

Question 34

Commercially prepared media are always exempt from quality control testing. true or false

Answer 34

false

Question 35

``` Penicillin susceptibility in isolates of Streptococcus pneumoniae can be determined using the following disk diffusion: penicillin methicillin oxacillin ampicillin ```

Answer 35

oxacillin

Question 36

Which of these criteria is not used by the laboratory in determining if antimicrobial susceptibility testing will be performed: Drugs of Choice Clinical significance Status of patient's immune system Reliable standardized methods for testing

Answer 36

Status of patient's immune system

Question 37

Quality control for AST disk diffusion was performed and it was noted that numerous zone sizes were too small. The test was repeated with a new lot number of mueller hinton agar and all zone sizes were within an acceptable range. Which is the best explanation for the unacceptable zones? Media was too thick Media was too thin Inoculum had too few organism (too light) Resistant mutants

Answer 37

media was too thick

Question 38

Resistance of Staphylococcus to methicillin, penicillin and other beta lactams may be detected by testing with this predictor drug

Answer 38

oxacillin

Question 39

Protein synthesis is the principal mode of action of which of these antimicrobial pairs?

Answer 39

gentamycin and erythromycin

Question 40

Direct beta- lactamase testing may be perfomed by using a/an:

Answer 40

cephalosporin (cefinase) disk

Question 41

When the activity of a combination of antimicrobials is substantially greater than the activity of the single most active one. The effect is:

Answer 41

Synergistic

Question 42

``` Extended spectrum beta lactamase (ESBL) testing will be useful as a part of the AST of Enterobacteriaceae Streptococcus spp. Staphylococcus spp. Enterococcus spp. ```

Answer 42

Enterobacteriaceae

Question 43

``` The "D" test will test for the resistance of which antimicrobial among S. aureus isolates. vancomycin clindamycin oxacillin linezolid ```

Answer 43

clindamycin

Question 44

Ampicillin treatment will acheive adequate levels in

Answer 44

blood fluid CFS