Question 1

How does Staphylococcus aureus acquire resistance to methicillin?

Accepted Answer

A)  An enzyme alteration 
B)  Mobile DNA element 
C)  Frameshift mutation 
D)  RNA porin 
A)  An enzyme alteration 
B)  Mobile DNA element 
C)  Frameshift mutation 
D)  RNA porin

Question 2

Streptococcus pneumoniae and Streptococcus pyogenes use efflux as an effective mechanism for acquired resistance to:

Accepted Answer

A)  Macrolides 
B)  Peptidoglycans 
C)  Aminoglycosides 
D)  Quinolones 
A)  Macrolides 
B)  Peptidoglycans 
C)  Aminoglycosides 
D)  Quinolones

Question 3

All of the following antibiotics target the 50S ribosomal subunit to prevent mRNA translation in the bacteria EXCEPT:

Accepted Answer

A)  Macrolides 
B)  Quinolones 
C)  Oxazolidinones 
D)  Streptogramins 
A)  Macrolides 
B)  Quinolones 
C)  Oxazolidinones 
D)  Streptogramins

Question 4

What is the mechanism of action of the glycopeptides (vancomycin and teicoplanin)?

Accepted Answer

A)  The glycopeptides inhibit folate synthesis and prevent the bacteria from using this as an energy source. 
B)  The glycopeptides interfere with DNA replication and disrupt the protein synthesis operation. 
C)  The glycopeptides bind to the substrate of the transpeptidation enzyme and disrupt the cell membrane construction. 
D)  The glycopeptides interfere with transfer RNA production and disrupt the protein synthesis operation. 
A)  The glycopeptides inhibit folate synthesis and prevent the bacteria from using this as an energy source. 
B)  The glycopeptides interfere with DNA replication and disrupt the protein synthesis operation. 
C)  The glycopeptides bind to the substrate of the transpeptidation enzyme and disrupt the cell membrane construction. 
D)  The glycopeptides interfere with transfer RNA production and disrupt the protein synthesis operation.

Question 5

Insertion sequences are:

Accepted Answer

A)  Circular structures present in bacteria that contain genes encoding proteins and RNA and the capacity to self-replicate and portion into daughter cells during cellular division 
B)  DNA elements that encode transposition and excision function and can transpose from one place on the chromosome to another 
C)  Genetic elements capable of integrating resistance genes (cassettes) by an integron-encoded, site-specific recombinase 
D)  DNA elements found in bacteria that carry genes only for the enzymes needed to promote their own transposition 
A)  Circular structures present in bacteria that contain genes encoding proteins and RNA and the capacity to self-replicate and portion into daughter cells during cellular division 
B)  DNA elements that encode transposition and excision function and can transpose from one place on the chromosome to another 
C)  Genetic elements capable of integrating resistance genes (cassettes) by an integron-encoded, site-specific recombinase 
D)  DNA elements found in bacteria that carry genes only for the enzymes needed to promote their own transposition

Question 6

Mechanisms that mediate intrinsic antibiotic resistance include all the following EXCEPT:

Accepted Answer

A)  Cell-wall impermeability 
B)  Biofilm formation 
C)  Expression of genes mediating inactivating enzymes 
D)  Alternate biosynthetic pathways 
A)  Cell-wall impermeability 
B)  Biofilm formation 
C)  Expression of genes mediating inactivating enzymes 
D)  Alternate biosynthetic pathways

Question 7

Extended b-lactamases target all the following antibiotics EXCEPT:

Accepted Answer

A)  Penicillins 
B)  Cephalosporins 
C)  Monobactams 
D)  Macrolides 
A)  Penicillins 
B)  Cephalosporins 
C)  Monobactams 
D)  Macrolides

Question 8

Integrons are:

Accepted Answer

A)  Circular structures present in bacteria that contain genes encoding proteins and RNA and have the capacity to self-replicate and portion into daughter cells during cellular division 
B)  DNA elements that encode transposition and excision function and can transpose from one place on the chromosome to another. 
C)  Genetic elements capable of integrating resistance genes (cassettes) by an integron-encoded, site-specific recombinase 
D)  DNA elements found in bacteria that carry genes only for the enzymes needed to promote their own transposition 
A)  Circular structures present in bacteria that contain genes encoding proteins and RNA and have the capacity to self-replicate and portion into daughter cells during cellular division 
B)  DNA elements that encode transposition and excision function and can transpose from one place on the chromosome to another. 
C)  Genetic elements capable of integrating resistance genes (cassettes) by an integron-encoded, site-specific recombinase 
D)  DNA elements found in bacteria that carry genes only for the enzymes needed to promote their own transposition

Question 9

The outer membrane of gram-negative bacteria is composed of:

Accepted Answer

A)  Lipopolysaccharides, phospholipids, and porin proteins 
B)  Peptidoglycan, phospholipids, and proteins 
C)  Enzymes, cholesterol, and carbohydrates 
D)  Carbohydrates, peptidoglycan, and proteins 
A)  Lipopolysaccharides, phospholipids, and porin proteins 
B)  Peptidoglycan, phospholipids, and proteins 
C)  Enzymes, cholesterol, and carbohydrates 
D)  Carbohydrates, peptidoglycan, and proteins

Question 10

β-Lactamases hydrolyze b-lactam antibiotics using two distinct mechanisms: those having a metallo-based mechanism of action and those with:

Accepted Answer

A)  Ring-specific enzymes 
B)  A serine-based mechanism of action 
C)  A chromosomal mechanism of action 
D)  A transporter mechanism of action 
A)  Ring-specific enzymes 
B)  A serine-based mechanism of action 
C)  A chromosomal mechanism of action 
D)  A transporter mechanism of action

Question 11

This antibiotic affects the DNA replication by targeting topoisomerases II and IV,enzymes considered important in controlling DNA replication.

Accepted Answer

A)  Glycopeptide 
B)  Sulfamethoxazole 
C)  Trimethoprim 
D)  Quinolone 
A)  Glycopeptide 
B)  Sulfamethoxazole 
C)  Trimethoprim 
D)  Quinolone

Question 12

Acquired antibiotic resistance mechanisms include:

Accepted Answer

A)  Efflux 
B)  Acquisition of new targets 
C)  Modification of existing antibiotic targets 
D)  All of the above 
A)  Efflux 
B)  Acquisition of new targets 
C)  Modification of existing antibiotic targets 
D)  All of the above

Question 13

What is a porin?

Accepted Answer

A)  An inner membrane pore that allows proteins out into the cytoplasm 
B)  Outer membrane pores that allow the membrane to "breathe" 
C)  Substrates for enzymes that enable protein synthesis 
D)  Outer membrane channels that permit the inflow of nutrients and the outflow of wastes 
A)  An inner membrane pore that allows proteins out into the cytoplasm 
B)  Outer membrane pores that allow the membrane to "breathe" 
C)  Substrates for enzymes that enable protein synthesis 
D)  Outer membrane channels that permit the inflow of nutrients and the outflow of wastes

Question 14

This is one of the first resistance mechanisms identified and is a strategy that bacteria use successfully to survive the action of many classes of antibiotics.

Accepted Answer

A)  Frameshift mutation 
B)  Plasmid DNA acquisition 
C)  Acquisition of inactivating enzymes 
D)  Impermeability to the cell wall 
A)  Frameshift mutation 
B)  Plasmid DNA acquisition 
C)  Acquisition of inactivating enzymes 
D)  Impermeability to the cell wall

Question 15

These two classes of antibiotics allow initiation and mRNA translation to begin,but they act by inhibiting peptide elongation.

Accepted Answer

A)  Aminoglycosides and glycopeptidians 
B)  Aminoglycosides and quinolones 
C)  Macrolides and tetracyclines 
D)  Macrolides and quinolones 
A)  Aminoglycosides and glycopeptidians 
B)  Aminoglycosides and quinolones 
C)  Macrolides and tetracyclines 
D)  Macrolides and quinolones

Question 16

Biofilms are groups of bacteria that are irreversibly attached to a solid and embedded in a matrix of extracellular polymeric substances.They are commonly found on:

Accepted Answer

A)  Organic heart valves 
B)  Dialysis shunts 
C)  Indwelling medical devices 
D)  Patient beds 
A)  Organic heart valves 
B)  Dialysis shunts 
C)  Indwelling medical devices 
D)  Patient beds

Question 17

Resistance to aminoglycosides is mediated by:

Accepted Answer

A)  Efflux 
B)  Changes in the target site 
C)  Impermeability or by enzymatic modification of amino and hydroxy moieties appended to the cyclitol rings 
D)  All of the above 
A)  Efflux 
B)  Changes in the target site 
C)  Impermeability or by enzymatic modification of amino and hydroxy moieties appended to the cyclitol rings 
D)  All of the above

Question 18

The mechanisms of action of antibiotics include all the following EXCEPT:

Accepted Answer

A)  Blocking the Embden-Meyerhof pathway 
B)  Bacterial cell wall synthesis 
C)  DNA replication 
D)  RNA transcription 
A)  Blocking the Embden-Meyerhof pathway 
B)  Bacterial cell wall synthesis 
C)  DNA replication 
D)  RNA transcription

Question 19

Acquired mechanisms of resistance are those that:

Accepted Answer

A)  Are passed on from one bacteria to the next using pili 
B)  Are the result of a frameshift mutation in chromosomal DNA 
C)  Result from acquisition of DNA by acquisition of extrachromosomal DNA 
D)  Passed on from generation to generation. 
A)  Are passed on from one bacteria to the next using pili 
B)  Are the result of a frameshift mutation in chromosomal DNA 
C)  Result from acquisition of DNA by acquisition of extrachromosomal DNA 
D)  Passed on from generation to generation.

Question 20

Penicillins,cephalosporins,monobactams,and carbapenems all have this ring in their structure that is responsible for inhibiting the transpeptidation reaction,resulting in bacterial lysis and cell death.

Accepted Answer

A)  Benzene 
B)  β-Lactam 
C)  α-Lactam 
D)  Δ-cephems 
A)  Benzene 
B)  β-Lactam 
C)  α-Lactam 
D)  Δ-cephems

Exam 12: Antibiotic Mechanisms of Action and Resistance

How does Staphylococcus aureus acquire resistance to methicillin?

Streptococcus pneumoniae and Streptococcus pyogenes use efflux as an effective mechanism for acquired resistance to:

All of the following antibiotics target the 50S ribosomal subunit to prevent mRNA translation in the bacteria EXCEPT:

What is the mechanism of action of the glycopeptides (vancomycin and teicoplanin)?

Insertion sequences are:

Mechanisms that mediate intrinsic antibiotic resistance include all the following EXCEPT:

Extended b-lactamases target all the following antibiotics EXCEPT:

Integrons are:

The outer membrane of gram-negative bacteria is composed of:

β-Lactamases hydrolyze b-lactam antibiotics using two distinct mechanisms: those having a metallo-based mechanism of action and those with:

This antibiotic affects the DNA replication by targeting topoisomerases II and IV,enzymes considered important in controlling DNA replication.

Acquired antibiotic resistance mechanisms include:

What is a porin?

This is one of the first resistance mechanisms identified and is a strategy that bacteria use successfully to survive the action of many classes of antibiotics.

These two classes of antibiotics allow initiation and mRNA translation to begin,but they act by inhibiting peptide elongation.

Biofilms are groups of bacteria that are irreversibly attached to a solid and embedded in a matrix of extracellular polymeric substances.They are commonly found on:

Resistance to aminoglycosides is mediated by:

The mechanisms of action of antibiotics include all the following EXCEPT:

Acquired mechanisms of resistance are those that:

Penicillins,cephalosporins,monobactams,and carbapenems all have this ring in their structure that is responsible for inhibiting the transpeptidation reaction,resulting in bacterial lysis and cell death.

Bacterial Cell Structure, physiology, Metabolism, and Genetics

Host-Parasite Interaction

Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Microscopic Examination of Infected Materials

Use of Colonial Morphology for the Presumptive Identification of Microorganisms

Biochemical Identification of Gram-Negative Bacteria

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antimicrobial Susceptibility Testing

Staphylococci

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

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio,aeromonas,plesiomonas and Campylobacter Species

Nonfermenting and Miscellaneous Gram-Negative Bacilli

Anaerobes of Clinical Importance

Spirochetes

Chlamydia and Rickettsia

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Other Nontuberculosis Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror

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 Diseases

Infections in Special Populations

Zoonotic Diseases

Ocular Infections

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