Beta-Lactams, Macrolides,
Quinolones & More –
Comprehensive Antimicrobial Test
2025/2026
1. A 25-year-old female presents with uncomplicated cystitis.
Which antibiotic is first-line therapy for this condition in a non-
pregnant patient?
A. Amoxicillin
B. Ciprofloxacin
C. Nitrofurantoin
D. Vancomycin
Rationale: Nitrofurantoin is first-line for uncomplicated cystitis due to E.
coli. Amoxicillin resistance is high, and fluoroquinolones are reserved for
complicated cases.
2. Which of the following antibiotics inhibits bacterial cell wall
synthesis?
A. Penicillin
B. Tetracycline
C. Ciprofloxacin
D. Azithromycin
Rationale: Penicillins and other beta-lactams inhibit cell wall synthesis
by binding to penicillin-binding proteins.
3. A patient with a history of severe penicillin allergy presents with
community-acquired pneumonia. Which antibiotic is safest to
prescribe?
, A. Amoxicillin
B. Ceftriaxone
C. Azithromycin
D. Piperacillin-tazobactam
Rationale: Azithromycin, a macrolide, is safe in penicillin allergy.
Ceftriaxone may have cross-reactivity in severe penicillin allergy.
4. Which of the following is bacteriostatic rather than bactericidal?
A. Penicillin
B. Vancomycin
C. Tetracycline
D. Aminoglycosides
Rationale: Tetracyclines inhibit protein synthesis, which is
bacteriostatic. Penicillin, vancomycin, and aminoglycosides are
bactericidal.
5. What is the mechanism of action of fluoroquinolones?
A. Inhibition of cell wall synthesis
B. Inhibition of DNA gyrase and topoisomerase IV
C. Inhibition of protein synthesis at 30S ribosomal subunit
D. Disruption of bacterial folate synthesis
Rationale: Fluoroquinolones inhibit DNA replication by targeting DNA
gyrase and topoisomerase IV.
6. A patient with MRSA bacteremia requires IV therapy. Which
antibiotic is considered first-line?
A. Ceftriaxone
B. Vancomycin
C. Piperacillin-tazobactam
D. Amoxicillin-clavulanate
,Rationale: Vancomycin is the first-line IV treatment for MRSA infections,
including bacteremia.
7. Which antibiotic is contraindicated in pregnancy due to risk of
fetal teeth discoloration?
A. Penicillin
B. Macrolides
C. Tetracyclines
D. Cephalosporins
Rationale: Tetracyclines cross the placenta and can cause permanent
teeth discoloration and inhibit bone growth in the fetus.
8. Which of the following is the drug of choice for treating
Pseudomonas aeruginosa infections?
A. Amoxicillin
B. Piperacillin-tazobactam
C. Vancomycin
D. Azithromycin
Rationale: Pseudomonas is resistant to many antibiotics; piperacillin-
tazobactam has reliable activity against it.
9. A patient develops Clostridioides difficile infection after
antibiotics. Which antibiotic is preferred for treatment?
A. Amoxicillin
B. Ciprofloxacin
C. Vancomycin (oral)
D. Gentamicin
Rationale: Oral vancomycin targets C. difficile in the gut. Metronidazole
is also an option for mild cases.
10. A 30-year-old male presents with syphilis. Which antibiotic is
the first-line therapy?
, A. Doxycycline
B. Benzathine penicillin G
C. Azithromycin
D. Ceftriaxone
Rationale: Benzathine penicillin G is the first-line treatment for all
stages of syphilis. Doxycycline is reserved for penicillin-allergic patients.
11. Which antibiotic class is associated with tendon rupture?
A. Macrolides
B. Cephalosporins
C. Fluoroquinolones
D. Sulfonamides
Rationale: Fluoroquinolones increase the risk of tendinitis and
tendon rupture, especially in older adults.
12. Which drug is the first-line treatment for uncomplicated
gonorrhea?
A. Azithromycin
B. Doxycycline
C. Ceftriaxone
D. Penicillin V
Rationale: Ceftriaxone is the CDC-recommended first-line
therapy for uncomplicated gonorrhea.
13. Which antibiotic is effective against atypical organisms in
pneumonia (e.g., Mycoplasma)?
A. Penicillin
B. Azithromycin
C. Vancomycin
D. Cefazolin
Rationale: Macrolides are effective against atypical respiratory
pathogens.
Quinolones & More –
Comprehensive Antimicrobial Test
2025/2026
1. A 25-year-old female presents with uncomplicated cystitis.
Which antibiotic is first-line therapy for this condition in a non-
pregnant patient?
A. Amoxicillin
B. Ciprofloxacin
C. Nitrofurantoin
D. Vancomycin
Rationale: Nitrofurantoin is first-line for uncomplicated cystitis due to E.
coli. Amoxicillin resistance is high, and fluoroquinolones are reserved for
complicated cases.
2. Which of the following antibiotics inhibits bacterial cell wall
synthesis?
A. Penicillin
B. Tetracycline
C. Ciprofloxacin
D. Azithromycin
Rationale: Penicillins and other beta-lactams inhibit cell wall synthesis
by binding to penicillin-binding proteins.
3. A patient with a history of severe penicillin allergy presents with
community-acquired pneumonia. Which antibiotic is safest to
prescribe?
, A. Amoxicillin
B. Ceftriaxone
C. Azithromycin
D. Piperacillin-tazobactam
Rationale: Azithromycin, a macrolide, is safe in penicillin allergy.
Ceftriaxone may have cross-reactivity in severe penicillin allergy.
4. Which of the following is bacteriostatic rather than bactericidal?
A. Penicillin
B. Vancomycin
C. Tetracycline
D. Aminoglycosides
Rationale: Tetracyclines inhibit protein synthesis, which is
bacteriostatic. Penicillin, vancomycin, and aminoglycosides are
bactericidal.
5. What is the mechanism of action of fluoroquinolones?
A. Inhibition of cell wall synthesis
B. Inhibition of DNA gyrase and topoisomerase IV
C. Inhibition of protein synthesis at 30S ribosomal subunit
D. Disruption of bacterial folate synthesis
Rationale: Fluoroquinolones inhibit DNA replication by targeting DNA
gyrase and topoisomerase IV.
6. A patient with MRSA bacteremia requires IV therapy. Which
antibiotic is considered first-line?
A. Ceftriaxone
B. Vancomycin
C. Piperacillin-tazobactam
D. Amoxicillin-clavulanate
,Rationale: Vancomycin is the first-line IV treatment for MRSA infections,
including bacteremia.
7. Which antibiotic is contraindicated in pregnancy due to risk of
fetal teeth discoloration?
A. Penicillin
B. Macrolides
C. Tetracyclines
D. Cephalosporins
Rationale: Tetracyclines cross the placenta and can cause permanent
teeth discoloration and inhibit bone growth in the fetus.
8. Which of the following is the drug of choice for treating
Pseudomonas aeruginosa infections?
A. Amoxicillin
B. Piperacillin-tazobactam
C. Vancomycin
D. Azithromycin
Rationale: Pseudomonas is resistant to many antibiotics; piperacillin-
tazobactam has reliable activity against it.
9. A patient develops Clostridioides difficile infection after
antibiotics. Which antibiotic is preferred for treatment?
A. Amoxicillin
B. Ciprofloxacin
C. Vancomycin (oral)
D. Gentamicin
Rationale: Oral vancomycin targets C. difficile in the gut. Metronidazole
is also an option for mild cases.
10. A 30-year-old male presents with syphilis. Which antibiotic is
the first-line therapy?
, A. Doxycycline
B. Benzathine penicillin G
C. Azithromycin
D. Ceftriaxone
Rationale: Benzathine penicillin G is the first-line treatment for all
stages of syphilis. Doxycycline is reserved for penicillin-allergic patients.
11. Which antibiotic class is associated with tendon rupture?
A. Macrolides
B. Cephalosporins
C. Fluoroquinolones
D. Sulfonamides
Rationale: Fluoroquinolones increase the risk of tendinitis and
tendon rupture, especially in older adults.
12. Which drug is the first-line treatment for uncomplicated
gonorrhea?
A. Azithromycin
B. Doxycycline
C. Ceftriaxone
D. Penicillin V
Rationale: Ceftriaxone is the CDC-recommended first-line
therapy for uncomplicated gonorrhea.
13. Which antibiotic is effective against atypical organisms in
pneumonia (e.g., Mycoplasma)?
A. Penicillin
B. Azithromycin
C. Vancomycin
D. Cefazolin
Rationale: Macrolides are effective against atypical respiratory
pathogens.
