Barkley Infectious Disease Practice ACTUAL
EXAM ALL QUESTIONS AND ANSWERS
ALREADY GRADED A+. 100% VERIFIED
SOLUTIONS | UPDATED PER LATEST
GUIDELINES | GRADED A+
Principles of Antimicrobial Therapy (Questions 1-15)
Question 1
Which of the following is a host factor that affects antibiotic use?
A. The cost of the antibiotic
B. The patient's allergy history and immune status
C. The number of doses per day
D. The route of administration
Correct Answer: B
Rationale: Host factors affecting antibiotic use include allergy history, immune status
(immunocompromised patients need bactericidal drugs), infection site complications (blood-
brain barrier, foreign bodies, perfusion), age, pregnancy/lactation, genetics, and drug
interactions .
Question 2
Which of the following is NOT an example of inappropriate antibiotic prescribing?
A. Prescribing antibiotics for the common cold
B. Prescribing antibiotics for confirmed streptococcal pharyngitis
C. Prescribing antibiotics for acute bronchitis in a healthy adult
D. Prescribing antibiotics for sinusitis without facial pain for 10 days
Correct Answer: B
Rationale: Antibiotics are appropriate for confirmed bacterial infections such as streptococcal
pharyngitis. Inappropriate use includes treating viral infections (common cold), bronchitis
(except in select cases), and sinusitis without evidence of bacterial infection .
,Question 3
What is the mechanism of action of fluoroquinolones and rifampin?
A. Inhibition of cell wall synthesis
B. Inhibition of bacterial protein synthesis
C. Inhibition of DNA or RNA synthesis
D. Inhibition of folic acid synthesis
Correct Answer: C
Rationale: Fluoroquinolones and rifampin are DNA or RNA synthesis inhibitors.
Fluoroquinolones inhibit DNA gyrase, while rifampin inhibits RNA polymerase .
Question 4
Which type of antibiotic is most likely to promote antibiotic resistance?
A. Narrow-spectrum antibiotics
B. Broad-spectrum antibiotics
C. Bacteriostatic antibiotics
D. Topical antibiotics
Correct Answer: B
Rationale: Broad-spectrum antibiotics are most likely to promote resistance because they affect
a wide range of bacteria, including normal flora, creating selective pressure for resistance .
Question 5
What is the mechanism of antibiotic resistance involving the transfer of extra-chromosomal
DNA between bacteria?
A. Spontaneous mutation
B. Conjugation via R-factor
C. Phage transduction
D. Transformation
Correct Answer: B
Rationale: Conjugation involves the transfer of R-factor (resistance plasmid) between bacteria,
primarily in gram-negative organisms. This can occur between normal flora and pathogens and
is responsible for multiple-drug resistant organisms .
,Question 6
According to CDC guidelines, which of the following is NOT a strategy to prevent antimicrobial
resistance?
A. Vaccinate to prevent infections
B. Remove catheters when no longer needed
C. Continue antibiotics until all symptoms resolve
D. Use local data to guide antibiotic selection
Correct Answer: C
Rationale: The CDC's campaign to prevent antimicrobial resistance includes: infection
prevention (vaccination, catheter removal), effective diagnosis and treatment, wise antibiotic
use, and prevention of transmission. Antibiotics should be stopped when infection has cleared
or bacterial infection is unlikely .
Question 7
Which patients should receive antibiotic prophylaxis?
A. All patients undergoing surgery
B. Select surgical patients, severely neutropenic patients, patients at risk for bacterial
endocarditis
C. All patients with fever
D. Patients with viral upper respiratory infections
Correct Answer: B
Rationale: Antibiotic prophylaxis is indicated for select surgical patients (cardiac, peripheral
vascular, orthopedic, GI, GYN hysterectomy), severely neutropenic patients, patients at risk for
bacterial endocarditis, and patients with recurrent UTIs .
Question 8
Which class of antibiotics is bactericidal and inhibits cell wall synthesis?
A. Tetracyclines
B. Penicillins
C. Macrolides
D. Sulfonamides
Correct Answer: B
, Rationale: Penicillins are bactericidal antibiotics that inhibit bacterial cell wall synthesis by
binding to penicillin-binding proteins and inhibiting transpeptidase. This disrupts the cross-
linking of peptidoglycan in the bacterial cell wall .
Question 9
What is the selective toxicity mechanism of antibiotics?
A. Ability to kill all microorganisms
B. Ability to disrupt bacterial cell wall or inhibit bacterial-specific processes without harming
human cells
C. Ability to be administered orally
D. Ability to be effective against all bacterial strains
Correct Answer: B
Rationale: Selective toxicity refers to the ability of antibiotics to disrupt bacterial cell wall
synthesis or inhibit bacterial protein synthesis, nucleic acid synthesis, or metabolic pathways
that are unique to bacteria, causing minimal harm to human cells .
Question 10
Which of the following is a mechanism of antibiotic resistance?
A. Production of drug-metabolizing enzymes
B. Decreased drug uptake
C. Change in drug receptor with decreased binding
D. All of the above
Correct Answer: D
Rationale: Mechanisms of antibiotic resistance include: 1) production of drug-metabolizing
enzymes (e.g., beta-lactamases), 2) decreased drug uptake, 3) change in drug receptor with
decreased binding of antibiotic, and 4) synthesis of compounds that antagonize the antibiotic .
Question 11
A patient with confirmed streptococcal pharyngitis has a penicillin allergy. What is the
appropriate alternative?
A. Azithromycin
B. Amoxicillin
EXAM ALL QUESTIONS AND ANSWERS
ALREADY GRADED A+. 100% VERIFIED
SOLUTIONS | UPDATED PER LATEST
GUIDELINES | GRADED A+
Principles of Antimicrobial Therapy (Questions 1-15)
Question 1
Which of the following is a host factor that affects antibiotic use?
A. The cost of the antibiotic
B. The patient's allergy history and immune status
C. The number of doses per day
D. The route of administration
Correct Answer: B
Rationale: Host factors affecting antibiotic use include allergy history, immune status
(immunocompromised patients need bactericidal drugs), infection site complications (blood-
brain barrier, foreign bodies, perfusion), age, pregnancy/lactation, genetics, and drug
interactions .
Question 2
Which of the following is NOT an example of inappropriate antibiotic prescribing?
A. Prescribing antibiotics for the common cold
B. Prescribing antibiotics for confirmed streptococcal pharyngitis
C. Prescribing antibiotics for acute bronchitis in a healthy adult
D. Prescribing antibiotics for sinusitis without facial pain for 10 days
Correct Answer: B
Rationale: Antibiotics are appropriate for confirmed bacterial infections such as streptococcal
pharyngitis. Inappropriate use includes treating viral infections (common cold), bronchitis
(except in select cases), and sinusitis without evidence of bacterial infection .
,Question 3
What is the mechanism of action of fluoroquinolones and rifampin?
A. Inhibition of cell wall synthesis
B. Inhibition of bacterial protein synthesis
C. Inhibition of DNA or RNA synthesis
D. Inhibition of folic acid synthesis
Correct Answer: C
Rationale: Fluoroquinolones and rifampin are DNA or RNA synthesis inhibitors.
Fluoroquinolones inhibit DNA gyrase, while rifampin inhibits RNA polymerase .
Question 4
Which type of antibiotic is most likely to promote antibiotic resistance?
A. Narrow-spectrum antibiotics
B. Broad-spectrum antibiotics
C. Bacteriostatic antibiotics
D. Topical antibiotics
Correct Answer: B
Rationale: Broad-spectrum antibiotics are most likely to promote resistance because they affect
a wide range of bacteria, including normal flora, creating selective pressure for resistance .
Question 5
What is the mechanism of antibiotic resistance involving the transfer of extra-chromosomal
DNA between bacteria?
A. Spontaneous mutation
B. Conjugation via R-factor
C. Phage transduction
D. Transformation
Correct Answer: B
Rationale: Conjugation involves the transfer of R-factor (resistance plasmid) between bacteria,
primarily in gram-negative organisms. This can occur between normal flora and pathogens and
is responsible for multiple-drug resistant organisms .
,Question 6
According to CDC guidelines, which of the following is NOT a strategy to prevent antimicrobial
resistance?
A. Vaccinate to prevent infections
B. Remove catheters when no longer needed
C. Continue antibiotics until all symptoms resolve
D. Use local data to guide antibiotic selection
Correct Answer: C
Rationale: The CDC's campaign to prevent antimicrobial resistance includes: infection
prevention (vaccination, catheter removal), effective diagnosis and treatment, wise antibiotic
use, and prevention of transmission. Antibiotics should be stopped when infection has cleared
or bacterial infection is unlikely .
Question 7
Which patients should receive antibiotic prophylaxis?
A. All patients undergoing surgery
B. Select surgical patients, severely neutropenic patients, patients at risk for bacterial
endocarditis
C. All patients with fever
D. Patients with viral upper respiratory infections
Correct Answer: B
Rationale: Antibiotic prophylaxis is indicated for select surgical patients (cardiac, peripheral
vascular, orthopedic, GI, GYN hysterectomy), severely neutropenic patients, patients at risk for
bacterial endocarditis, and patients with recurrent UTIs .
Question 8
Which class of antibiotics is bactericidal and inhibits cell wall synthesis?
A. Tetracyclines
B. Penicillins
C. Macrolides
D. Sulfonamides
Correct Answer: B
, Rationale: Penicillins are bactericidal antibiotics that inhibit bacterial cell wall synthesis by
binding to penicillin-binding proteins and inhibiting transpeptidase. This disrupts the cross-
linking of peptidoglycan in the bacterial cell wall .
Question 9
What is the selective toxicity mechanism of antibiotics?
A. Ability to kill all microorganisms
B. Ability to disrupt bacterial cell wall or inhibit bacterial-specific processes without harming
human cells
C. Ability to be administered orally
D. Ability to be effective against all bacterial strains
Correct Answer: B
Rationale: Selective toxicity refers to the ability of antibiotics to disrupt bacterial cell wall
synthesis or inhibit bacterial protein synthesis, nucleic acid synthesis, or metabolic pathways
that are unique to bacteria, causing minimal harm to human cells .
Question 10
Which of the following is a mechanism of antibiotic resistance?
A. Production of drug-metabolizing enzymes
B. Decreased drug uptake
C. Change in drug receptor with decreased binding
D. All of the above
Correct Answer: D
Rationale: Mechanisms of antibiotic resistance include: 1) production of drug-metabolizing
enzymes (e.g., beta-lactamases), 2) decreased drug uptake, 3) change in drug receptor with
decreased binding of antibiotic, and 4) synthesis of compounds that antagonize the antibiotic .
Question 11
A patient with confirmed streptococcal pharyngitis has a penicillin allergy. What is the
appropriate alternative?
A. Azithromycin
B. Amoxicillin
