Exam 1 - (CH 12) Antibacterial Mechanisms of Action and Bacterial Resistance Mechanisms Textbook Review Questions Flashcards
Which of the following antibiotics is a β-lactam?
A. Rifampin
B. Lincosamides
C. Chloramphenicol
D. Carbapenems
D. Carbapenems
Trimethoprim prevents
A. recycling of folate coenzymes required for DNA biosynthesis.
B. decatenation at the end of bacterial DNA replication.
C. the transpeptidation step in cell wall biosynthesis.
D. RNA polymerase β subunit from continuing RNA chain elongation.
A. recycling of folate coenzymes required for DNA biosynthesis.
Which antibiotic class targets the 50S ribosomal subunit?
A. Aminoglycosides
B. Tetracyclines
C. Macrolides
D. Teicoplanin
C. Macrolides
Tetracyclines
A. are bacteriostatic β-lactams.
B. are only used to treat pseudomonad infections.
C. allow mRNA translation but inhibit peptide elongation.
D. interfere with DNA transcription by binding the 50S subunit of 16S RNA.
C. allow mRNA translation but inhibit peptide elongation.
An example of a macrolide is
A. vancomycin.
B. clarithromycin.
C. telavancin.
D. sulfamethoxazole.
B. clarithromycin.
The New Delhi metallo-β-lactamase-1 hydrolyzes all of the following except
A. penicillins.
B. cephalosporins.
C. aztreonam.
D. carbapenems.
C. aztreonam.
Which of the following are used to enhance the range by preventing the degradation of β-lactam antibiotics?
A. MICs
B. AACs
C. Vat(E)s
D. BLIs
D. BLIs
Plasmid NR1 isolated from this organism is the archetype plasmid responsible for dissemination of Tns and plasmid antimicrobial resistance.
A. Klebsiella pneumoniae
B. Enterobacter aerogenes
C. Streptomyces spectabilis
D. Shigella flexneri
D. Shigella flexneri
Which of the following is a β-lactamase inhibitor with a β-lactam core?
A. Avibactam
B. Ceftazidime
C. Tazobactam
D. Aztreonam
C. Tazobactam
Antibiotics can be:
a. Natural molecules.
b. Synthetic molecules.
c. Semisynthetic molecules.
d. All of the above.
d. All of the above.
Which of the listed antimicrobials act on cell wall biosynthesis?
a. β-Lactams and glycopeptides
b. Tetracycline and streptomycin
c. Macrolides and phenicols
d. Fluoroquinolone and sulfamethoxazole
a. β-Lactams and glycopeptides
Which of the antimicrobials are new analogs of older classes?
a. Glycylcycline from tetracyclines
b. Ketolides from macrolides
c. Fluoroquinolone from glycopeptides
d. Both a and c
e. Both a and b
e. Both a and b
The most commonly used inhibitors of cell wall biosynthesis act on:
a. Transportation of lipid-bound precursors across the cytoplasmic membranes.
b. Insertion of glycan units into the cell wall.
c. Transpeptidation linking and maturation.
d. Synthesis of precursors in the cytoplasm.
e. Both b and c
e. Both b and c
Which of the antimicrobial classes include semisynthetic and natural derivatives?
a. Glycopeptides
b. Aminoglycosides
c. β-Lactams
d. Fluoroquinolones
e. All except d
e. All except d
Microorganisms can exhibit antimicrobial resistance by which of the following mechanisms?
a. Intrinsic
b. Acquired
c. Both
d. Neither
c. Both
Which mechanisms of antimicrobial resistance are intrinsic and acquired?
a. Efflux
b. Enzymatic
c. Biofilm
d. Acquisition of new targets
e. Both a and b
e. Both a and b
Plasmids can contain which of the following?
a. Transposons
b. Insertion sequences
c. Integron cassettes
d. All of the above
e. Both a and c
d. All of the above
Transposons do not contain which of the following?
a. Cytoplasmic membranes
b. Transposase
c. Excision protein genes
d. Antibiotic resistance determinants
e. Conjugative functions
a. Cytoplasmic membranes
Which of the following characteristics apply to efflux pumps?
a. They are found in gram-positive and gram-negative bacteria.
b. They are transporter proteins.
c. They have single or multiple substrates.
d. Both a and c.
e. All of the above.
e. All of the above.
Which of the following does not apply to antimicrobial resistance caused by target site modification?
a. Chromosomal mutation of target site
b. Quinolone resistance– determining region
c. SCCmec
d. Erythromycin-resistant methylase
c. SCCmec
Enzymatic modification of aminoglycosides is not caused by which of the following?
a. N-acetylation
b. Dimethylation
c. O-phosphorylation
d. O-adenylation
b. Dimethylation
Which of the following is not a characteristic of integrons?
a. Potentially mobile element
b. Gene cassettes
c. 59-bp element
d. Peptidoglycan
d. Peptidoglycan
Serine-based β-lactamases appear to have evolved from the penicillin-binding proteins of bacteria. True or false?
True
Which of the following is a non– β-lactam β-lactamase inhibitor?
a. Ticarcillin
b. Avibactam
c. Clavulanate
d. Sulbactam
b. Avibactam
Points to Remember
■ Although resistance to antimicrobial agents may be genetically intrinsic or acquired, both types can be found in the same pathogen.
■ β-Lactam antibiotics, which work by inhibiting cell wall synthesis, contain a four-member ring and include the penicillins, cephalosporins, monobactams, and carbapenems.
■ The quinolones interfere with DNA replication by targeting DNA gyrases and topoisomerases.
■ Protein inhibitors include aminoglycosides, tetracyclines, macrolides, streptogramins, chloramphenicol, and linezolid.
■ Impermeability and efflux mechanism of resistance can produce multidrug-resistant phenotypes.
■ A single organism may acquire multiple mechanisms of resistance, including different mechanisms of conferring resistance to the same compound.
■ Antimicrobial mechanisms of resistance and their dissemination are not static processes.
■ Nanoparticles are being used to deliver various drugs, including antimicrobial agents, into tissue.
