Question 1

When performing disk diffusion testing with Haemophilus influenzae and H. parainfluenzae, what type of medium is used?

Accepted Answer

A)  Mueller-Hinton with 5% sheep blood 
B)  Mueller-Hinton with hematin and nicotinamide adenine dinucleotide (NA
D)  
C)  Mueller-Hinton with 5% lysed horse blood 
D)  Mueller-Hinton 
A)  Mueller-Hinton with 5% sheep blood 
B)  Mueller-Hinton with hematin and nicotinamide adenine dinucleotide (NA
D)  
C)  Mueller-Hinton with 5% lysed horse blood 
D)  Mueller-Hinton

Question 2

The inhibition zone size and MIC interpretive criteria published by the CLSI are established by careful analysis of all of the following, except

Accepted Answer

A)  microbiologic data. 
B)  pharmacokinetic data. 
C)  results of clinical studies during the phase before FDA approval. 
D)  pharmacodynamic data. 
A)  microbiologic data. 
B)  pharmacokinetic data. 
C)  results of clinical studies during the phase before FDA approval. 
D)  pharmacodynamic data.

Question 3

Oxacillin-resistant staphylococci can appear susceptible in vitro to other $\beta$-lactam agents such as

Accepted Answer

A)  quinolones. 
B)  tetracyclines. 
C)  cephalosporins. 
D)  aminoglycosides. 
A)  quinolones. 
B)  tetracyclines. 
C)  cephalosporins. 
D)  aminoglycosides.

Question 4

To obtain a bactericidal effect in enterococci, ampicillin or penicillin must be given in combination with

Accepted Answer

A)  macrolides. 
B)  peptidoglycans. 
C)  cephalosporins. 
D)  aminoglycosides. 
A)  macrolides. 
B)  peptidoglycans. 
C)  cephalosporins. 
D)  aminoglycosides.

Question 5

The broth microdilution MIC test uses these for the testing.

Accepted Answer

A)  Test tubes 
B)  Plastic strips 
C)  Multiwell microdilution trays 
D)  Multiwell macrodilution trays 
A)  Test tubes 
B)  Plastic strips 
C)  Multiwell microdilution trays 
D)  Multiwell macrodilution trays

Question 6

The minimal inhibitory concentration (MIC) is

Accepted Answer

A)  the lowest antibiotic concentration to slow the growth of an organism. 
B)  the highest antibiotic concentration to slow the growth of an organism. 
C)  the lowest antibiotic concentration to inhibit the growth of an organism. 
D)  the highest antibiotic concentration to inhibit the growth of an organism. 
A)  the lowest antibiotic concentration to slow the growth of an organism. 
B)  the highest antibiotic concentration to slow the growth of an organism. 
C)  the lowest antibiotic concentration to inhibit the growth of an organism. 
D)  the highest antibiotic concentration to inhibit the growth of an organism.

Question 7

The BD Phoenix system uses this principle to measure bacterial growth in the susceptibility test wells.

Accepted Answer

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

Question 8

Because the identity of the bacterial isolate is often unknown at the time the susceptibility testing is performed, it may include drugs that are inappropriate for reporting. What does the microbiologist do when this occurs?

Accepted Answer

A)  A drug should not be indiscriminately reported because results may be misleading. 
B)  If the drug is tested, the results are reported because the microbiologist does not know what antibiotic was prescribed to the patient. 
C)  The microbiologist reports this immediately to the microbiology supervisor because this is a wasteful practice. 
D)  The microbiologist only reports on the drugs to which the bacteria are sensitive. 
A)  A drug should not be indiscriminately reported because results may be misleading. 
B)  If the drug is tested, the results are reported because the microbiologist does not know what antibiotic was prescribed to the patient. 
C)  The microbiologist reports this immediately to the microbiology supervisor because this is a wasteful practice. 
D)  The microbiologist only reports on the drugs to which the bacteria are sensitive.

Question 9

How long are MIC panels for anaerobes incubated?

Accepted Answer

A)  24 hours 
B)  36 hours 
C)  48 hours 
D)  72 hours 
A)  24 hours 
B)  36 hours 
C)  48 hours 
D)  72 hours

Question 10

Who sets the criteria in the table of values that relates the diameter of the zone to a category of susceptibility in disk diffusion testing?

Accepted Answer

A)  CDC 
B)  College of American Pathologists (CAP) 
C)  CLSI 
D)  Joint Commission on Accreditation of Healthcare Organizations (JCAHO) 
A)  CDC 
B)  College of American Pathologists (CAP) 
C)  CLSI 
D)  Joint Commission on Accreditation of Healthcare Organizations (JCAHO)

Question 11

A primary tenet of antimicrobial therapy is to use

Accepted Answer

A)  the least toxic agents. 
B)  the most cost-effective agents. 
C)  the most clinically effective agents. 
D)  All of the above 
A)  the least toxic agents. 
B)  the most cost-effective agents. 
C)  the most clinically effective agents. 
D)  All of the above

Question 12

The CLSI has published methods for susceptibility testing of several agents of potential bioterrorism, including Brucella anthracis, Yersinia pestis, Burkholderia mallei, B. pseudomallei, Francisella tularensis, and Brucella spp. How does CLSI suggest clinical laboratories perform antimicrobial susceptibility testing on these isolates?

Accepted Answer

A)  Use the agar dilution technique. 
B)  Use the Kirby-Bauer method. 
C)  Use the MIC plates. 
D)  Do not attempt to perform antimicrobial susceptibility on any of these isolates; refer them to a public health laboratory equipped to handle them. 
A)  Use the agar dilution technique. 
B)  Use the Kirby-Bauer method. 
C)  Use the MIC plates. 
D)  Do not attempt to perform antimicrobial susceptibility on any of these isolates; refer them to a public health laboratory equipped to handle them.

Question 13

What is a breakpoint panel?

Accepted Answer

A)  A standard MIC panel that contains many more dilution wells for each drug tested. 
B)  An MIC panel with only three or four drugs tested. 
C)  An MIC panel with only one or a few concentrations of each drug. 
D)  An MIC panel that contains nonroutine drugs. 
A)  A standard MIC panel that contains many more dilution wells for each drug tested. 
B)  An MIC panel with only three or four drugs tested. 
C)  An MIC panel with only one or a few concentrations of each drug. 
D)  An MIC panel that contains nonroutine drugs.

Question 14

What automated system was originally designed for use in outer space?

Accepted Answer

A)  TREK ARIS 
B)  MicroScan Walkaway SI 
C)  BD Phoenix 
D)  VITEK 
A)  TREK ARIS 
B)  MicroScan Walkaway SI 
C)  BD Phoenix 
D)  VITEK

Question 15

What principle do most current automated antimicrobial susceptibility instruments use to read growth?

Accepted Answer

A)  Turbidimetric detection 
B)  Turbidity suppression 
C)  Hydrolysis of a fluorogenic growth substrate 
D)  Carbon dioxide concentration 
A)  Turbidimetric detection 
B)  Turbidity suppression 
C)  Hydrolysis of a fluorogenic growth substrate 
D)  Carbon dioxide concentration

Question 16

On a breakpoint panel, when two concentrations are tested and no growth is present in either well, 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 17

All of the following techniques are used to measure the amount of antimicrobial agent in the serum, except

Accepted Answer

A)  biologic assays. 
B)  immunoassays. 
C)  chromatographic assays. 
D)  bioluminescence assays. 
A)  biologic assays. 
B)  immunoassays. 
C)  chromatographic assays. 
D)  bioluminescence assays.

Question 18

What antibiotics are active against ESBL-producing strains of bacteria?

Accepted Answer

A)  Cephalosporins 
B)  Penicillins 
C)  Carbapenems 
D)  Aztreonam 
A)  Cephalosporins 
B)  Penicillins 
C)  Carbapenems 
D)  Aztreonam

Question 19

Why would normal flora isolating from immunosuppressed patients undergo antimicrobial susceptibility testing?

Accepted Answer

A)  These are not normal flora; they are other potential pathogens that have the same colonial morphology as normal flora. 
B)  Species usually viewed as normal flora may be responsible for an infection in an immunosuppressed patient. 
C)  All bacteria isolated from immunosuppressed patients must have antimicrobial susceptibility tests performed. 
D)  Cultures from immunosuppressed patients only grow pathogenic organisms that must undergo antimicrobial susceptibility testing. 
A)  These are not normal flora; they are other potential pathogens that have the same colonial morphology as normal flora. 
B)  Species usually viewed as normal flora may be responsible for an infection in an immunosuppressed patient. 
C)  All bacteria isolated from immunosuppressed patients must have antimicrobial susceptibility tests performed. 
D)  Cultures from immunosuppressed patients only grow pathogenic organisms that must undergo antimicrobial susceptibility testing.

Question 20

On a breakpoint panel, when there is growth in both wells, 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

Exam 13: Antimicrobial Susceptibility Testing

When performing disk diffusion testing with Haemophilus influenzae and H. parainfluenzae, what type of medium is used?

The inhibition zone size and MIC interpretive criteria published by the CLSI are established by careful analysis of all of the following, except

Oxacillin-resistant staphylococci can appear susceptible in vitro to other β\betaβ -lactam agents such as

To obtain a bactericidal effect in enterococci, ampicillin or penicillin must be given in combination with

The broth microdilution MIC test uses these for the testing.

The minimal inhibitory concentration (MIC) is

The BD Phoenix system uses this principle to measure bacterial growth in the susceptibility test wells.

Because the identity of the bacterial isolate is often unknown at the time the susceptibility testing is performed, it may include drugs that are inappropriate for reporting. What does the microbiologist do when this occurs?

How long are MIC panels for anaerobes incubated?

Who sets the criteria in the table of values that relates the diameter of the zone to a category of susceptibility in disk diffusion testing?

A primary tenet of antimicrobial therapy is to use

What is a breakpoint panel?

What automated system was originally designed for use in outer space?

What principle do most current automated antimicrobial susceptibility instruments use to read growth?

On a breakpoint panel, when two concentrations are tested and no growth is present in either well, the isolate is

All of the following techniques are used to measure the amount of antimicrobial agent in the serum, except

What antibiotics are active against ESBL-producing strains of bacteria?

Why would normal flora isolating from immunosuppressed patients undergo antimicrobial susceptibility testing?

On a breakpoint panel, when there is growth in both wells, the isolate is

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

Oxacillin-resistant staphylococci can appear susceptible in vitro to other $\beta$ -lactam agents such as