Question 1

What principle does the TREK ARIS 2X System use to determine antimicrobial susceptibility?

Accepted Answer

A)  Redox indicator system 
B)  Turbidimetry 
C)  Hydrolysis of a fluorogenic substrate 
D)  Carbon dioxide concentration 
A)  Redox indicator system 
B)  Turbidimetry 
C)  Hydrolysis of a fluorogenic substrate 
D)  Carbon dioxide concentration C

Question 2

All of the following steps are taken to verify the results from an atypical antibiogram, except

Accepted Answer

A)  reexamining the disk diffusion plate, or MIC tray, to ensure that results were properly interpreted. 
B)  checking earlier reports to see whether the particular patient previously had an isolate with an atypical antibiogram. 
C)  calling around to other hospitals to see if they are encountering the same organism with that same antibiogram. 
D)  repeating the test, if necessary. 
A)  reexamining the disk diffusion plate, or MIC tray, to ensure that results were properly interpreted. 
B)  checking earlier reports to see whether the particular patient previously had an isolate with an atypical antibiogram. 
C)  calling around to other hospitals to see if they are encountering the same organism with that same antibiogram. 
D)  repeating the test, if necessary. C

Question 3

When reading broth microdilution MIC testing, the MIC for a particular drug is

Accepted Answer

A)  the lowest concentration showing no obvious growth. 
B)  the highest concentration showing no obvious growth. 
C)  the lowest concentration showing confluent growth. 
D)  the highest concentration showing confluent growth. 
A)  the lowest concentration showing no obvious growth. 
B)  the highest concentration showing no obvious growth. 
C)  the lowest concentration showing confluent growth. 
D)  the highest concentration showing confluent growth. A

Question 4

As a general guideline, it is suggested that within a particular antimicrobial class, primary (group A) agents should be reported first and secondary (group B) agents should be reported only if

Accepted Answer

A)  the physician insists that a secondary agent be reported. 
B)  the hospital pharmacy no longer stocks the group A agent. 
C)  the patient cannot tolerate the primary agents. 
D)  the FDA has recalled the primary agents. 
A)  the physician insists that a secondary agent be reported. 
B)  the hospital pharmacy no longer stocks the group A agent. 
C)  the patient cannot tolerate the primary agents. 
D)  the FDA has recalled the primary agents.

Question 5

In the Kirby-Bauer test, what is used to grow streptococci that do not grow adequately on unsupplemented Mueller-Hinton agar?

Accepted Answer

A)  Chocolate agar 
B)  PEA agar 
C)  Mueller-Hinton agar with 5% sheep blood 
D)  Mueller-Hinton agar with 5% rabbit blood 
A)  Chocolate agar 
B)  PEA agar 
C)  Mueller-Hinton agar with 5% sheep blood 
D)  Mueller-Hinton agar with 5% rabbit blood

Question 6

Spontaneous mutations occur in the $\beta$-lactamase genes that result in extended-spectrum $\beta$-lactamases (ESBL). These ESBL inactivate

Accepted Answer

A)  cephalosporins. 
B)  penicillins. 
C)  aztreonam. 
D)  All of the above 
A)  cephalosporins. 
B)  penicillins. 
C)  aztreonam. 
D)  All of the above

Question 7

What is generated by analysis of individual susceptibility results on isolates from a particular institution in a defined period and represents the percentage of isolates of a given species that is susceptible to the antimicrobial agents commonly tested against the species?

Accepted Answer

A)  Historical antibiogram 
B)  Laboratory workload report 
C)  Infection control committee report 
D)  Cumulative antibiogram 
A)  Historical antibiogram 
B)  Laboratory workload report 
C)  Infection control committee report 
D)  Cumulative antibiogram

Question 8

A patient is admitted to the hospital with a diagnosis of endocarditis. Two separate blood cultures grow out of viridans streptococci. The penicillin MIC of the organism is 0.12 µg/mL. What antibiotic should the physician prescribe?

Accepted Answer

A)  Penicillin 
B)  Erythromycin 
C)  Clindamycin 
D)  Gentamicin 
A)  Penicillin 
B)  Erythromycin 
C)  Clindamycin 
D)  Gentamicin

Question 9

Advantages of the commercial microdilution susceptibility test methods include all the following, except

Accepted Answer

A)  more accurate results than manual methods. 
B)  automated panel readers. 
C)  the quantitative nature of a MIC. 
D)  computerized data management systems. 
A)  more accurate results than manual methods. 
B)  automated panel readers. 
C)  the quantitative nature of a MIC. 
D)  computerized data management systems.

Question 10

On a breakpoint panel, when there is growth in the low concentration but no growth in the high concentration, the isolate is

Accepted Answer

A)  susceptible. 
B)  resistant. 
C)  intermediate. 
D)  None of the above 
A)  susceptible. 
B)  resistant. 
C)  intermediate. 
D)  None of the above

Question 11

What concentrations of antibiotics are typically tested in MICs?

Accepted Answer

A)  Serial fivefold dilution concentrations are tested. 
B)  Serial 10-fold dilution concentrations are tested. 
C)  Serial onefold dilution concentrations are tested. 
D)  Serial twofold dilution concentrations are tested. 
A)  Serial fivefold dilution concentrations are tested. 
B)  Serial 10-fold dilution concentrations are tested. 
C)  Serial onefold dilution concentrations are tested. 
D)  Serial twofold dilution concentrations are tested.

Question 12

When the activity of the combination of antimicrobial agents is less than that of the single agents, we say the agents are

Accepted Answer

A)  synergistic. 
B)  antagonistic. 
C)  indifferent. 
D)  uncomplicated. 
A)  synergistic. 
B)  antagonistic. 
C)  indifferent. 
D)  uncomplicated.

Question 13

If the MIC or zone size is interpreted as resistant using the latest CLSI tables

Accepted Answer

A)  the clinical interpretation of the result is that the patient's infecting organism should respond to therapy with that antimicrobial agent using the dosage normally recommended for that type of infection and that species. 
B)  the patient's infecting organism is unlikely to be inhibited by the usually achievable concentrations of the antimicrobial agent based on the dosages normally used with that drug. 
C)  the patient's infecting organism is likely to require the maximum amount of antimicrobial or more than can be achieved and for which the clinical response is likely to be less than with a susceptible strain. 
D)  None of the above 
A)  the clinical interpretation of the result is that the patient's infecting organism should respond to therapy with that antimicrobial agent using the dosage normally recommended for that type of infection and that species. 
B)  the patient's infecting organism is unlikely to be inhibited by the usually achievable concentrations of the antimicrobial agent based on the dosages normally used with that drug. 
C)  the patient's infecting organism is likely to require the maximum amount of antimicrobial or more than can be achieved and for which the clinical response is likely to be less than with a susceptible strain. 
D)  None of the above

Question 14

What antibiotics should be reported for urinary tract infections?

Accepted Answer

A)  Group A antibiotics 
B)  Group B antibiotics 
C)  Urinary tract active agents 
D)  Group C antibiotics 
A)  Group A antibiotics 
B)  Group B antibiotics 
C)  Urinary tract active agents 
D)  Group C antibiotics

Question 15

How many hours of incubation are necessary for the antimicrobial susceptibility test run on the BD Phoenix?

Accepted Answer

A)  6 to 8 hours 
B)  8 to 12 hours 
C)  12 to 18 hours 
D)  24 hours 
A)  6 to 8 hours 
B)  8 to 12 hours 
C)  12 to 18 hours 
D)  24 hours

Question 16

How should quality control testing occur?

Accepted Answer

A)  One specified microbiologist should use extreme care when doing quality control testing, using special pipettes, special agar plates, and special incubators. 
B)  The procedure should be followed to a T, and if any mistake is made, the test should be discarded and started again. 
C)  The microbiology supervisor should perform all quality control testing. 
D)  Quality control testing should be included in all the patients tested and treated like a patient specimen. 
A)  One specified microbiologist should use extreme care when doing quality control testing, using special pipettes, special agar plates, and special incubators. 
B)  The procedure should be followed to a T, and if any mistake is made, the test should be discarded and started again. 
C)  The microbiology supervisor should perform all quality control testing. 
D)  Quality control testing should be included in all the patients tested and treated like a patient specimen.

Question 17

What type of antimicrobial susceptibility testing method does CLSI recommend for anaerobes?

Accepted Answer

A)  Microdilution 
B)  Agar dilution 
C)  Tube broth macrodilution 
D)  Disk diffusion 
A)  Microdilution 
B)  Agar dilution 
C)  Tube broth macrodilution 
D)  Disk diffusion

Question 18

When testing Escherichia coli, Klebsiella spp., and Proteus mirabilis, which drug is mostly likely to indicate the presence of an ESBL?

Accepted Answer

A)  Aztreonam 
B)  Cefpodoxime 
C)  Ceftriaxone 
D)  Ceftazidime 
A)  Aztreonam 
B)  Cefpodoxime 
C)  Ceftriaxone 
D)  Ceftazidime

Question 19

The minimum bactericidal concentration (MBC) test differs from the MIC test because the MIC test gives the concentration needed at the site of infection to inhibit bacterial multiplications, whereas the MBC gives

Accepted Answer

A)  the highest concentration of antimicrobial that will kill an organism. 
B)  the amount of antimicrobial that must be achieved at the infection site to inhibit the organism. 
C)  the amount of antimicrobial that must be achieved at the infection site to kill the organism. 
D)  None of the above 
A)  the highest concentration of antimicrobial that will kill an organism. 
B)  the amount of antimicrobial that must be achieved at the infection site to inhibit the organism. 
C)  the amount of antimicrobial that must be achieved at the infection site to kill the organism. 
D)  None of the above

Question 20

Why should antimicrobial susceptibility testing of normal flora isolates or isolates likely to represent contamination or colonization not be performed?

Accepted Answer

A)  This may encourage a physician to treat a normal condition. 
B)  This will expose normal flora to various antibiotics and cause resistance to develop. 
C)  The amount of antibiotic needed to kill all of the normal flora in a site can cause toxic effects to the patient. 
D)  Antimicrobial susceptibility testing should be performed on all bacteria isolated from the patient. 
A)  This may encourage a physician to treat a normal condition. 
B)  This will expose normal flora to various antibiotics and cause resistance to develop. 
C)  The amount of antibiotic needed to kill all of the normal flora in a site can cause toxic effects to the patient. 
D)  Antimicrobial susceptibility testing should be performed on all bacteria isolated from the patient.

Exam 13: Antimicrobial Susceptibility Testing

What principle does the TREK ARIS 2X System use to determine antimicrobial susceptibility?

All of the following steps are taken to verify the results from an atypical antibiogram, except

When reading broth microdilution MIC testing, the MIC for a particular drug is

As a general guideline, it is suggested that within a particular antimicrobial class, primary (group A) agents should be reported first and secondary (group B) agents should be reported only if

In the Kirby-Bauer test, what is used to grow streptococci that do not grow adequately on unsupplemented Mueller-Hinton agar?

Spontaneous mutations occur in the β\betaβ -lactamase genes that result in extended-spectrum β\betaβ -lactamases (ESBL). These ESBL inactivate

What is generated by analysis of individual susceptibility results on isolates from a particular institution in a defined period and represents the percentage of isolates of a given species that is susceptible to the antimicrobial agents commonly tested against the species?

A patient is admitted to the hospital with a diagnosis of endocarditis. Two separate blood cultures grow out of viridans streptococci. The penicillin MIC of the organism is 0.12 µg/mL. What antibiotic should the physician prescribe?

Advantages of the commercial microdilution susceptibility test methods include all the following, except

On a breakpoint panel, when there is growth in the low concentration but no growth in the high concentration, the isolate is

What concentrations of antibiotics are typically tested in MICs?

When the activity of the combination of antimicrobial agents is less than that of the single agents, we say the agents are

If the MIC or zone size is interpreted as resistant using the latest CLSI tables

What antibiotics should be reported for urinary tract infections?

How many hours of incubation are necessary for the antimicrobial susceptibility test run on the BD Phoenix?

How should quality control testing occur?

What type of antimicrobial susceptibility testing method does CLSI recommend for anaerobes?

When testing Escherichia coli, Klebsiella spp., and Proteus mirabilis, which drug is mostly likely to indicate the presence of an ESBL?

The minimum bactericidal concentration (MBC) test differs from the MIC test because the MIC test gives the concentration needed at the site of infection to inhibit bacterial multiplications, whereas the MBC gives

Why should antimicrobial susceptibility testing of normal flora isolates or isolates likely to represent contamination or colonization not be performed?

Bacterial Cell Structure, Physiology, Metabolism, and Genetics

Hostparasite Interaction

The Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Microscopic Examination of Materials From Infected Sites

Use of Colony Morphology for the Presumptive Identification of Microorganisms

Biochemical Identification of Gram-Negative Bacteria

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antimicrobial Agent Mechanisms of Action and Resistance Mechanisms

Staphylococci

Streptococcus, Enterococcus, and Other Catalase-Negative, Gram-Positive Cocci

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus, Hacek, Legionella, and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio, Aeromonas, and Campylobacter Species

Nonfermenting and Miscellaneous Gram-Negative Bacilli

Anaerobes of Clinical Importance

The Spirochetes

Chlamydia, Rickettsia, and Similar Organisms

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Nontuberculous Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror and Forensic Microbiology

Biofilms: Architects of Disease

Upper and Lower Respiratory Tract Infections

Skin and Soft Tissue Infections

Gastrointestinal Infections and Food Poisoning

Infections of the Central Nervous System

Bacteremia and Sepsis

Urinary Tract Infections

Genital Infections and Sexually Transmitted Infections

Infections in Special Populations

Zoonotic Diseases

Ocular Infections

Filters

Spontaneous mutations occur in the $\beta$ -lactamase genes that result in extended-spectrum $\beta$ -lactamases (ESBL). These ESBL inactivate