Mock Exam: Antimicrobial Drugs

The principle that antimicrobial drugs should harm the microbe but not the host is called:

c. Selective toxicity

Broad-spectrum antibiotics:

c. Target a wide range of bacteria

Which of these is NOT a mode of action for antimicrobial drugs?

c. Inhibition of viral uncoating

Penicillin’s work by:

c. Inhibiting cell wall synthesis

Which class of antibiotics targets bacterial 70S ribosomes?

d. Tetracyclines

Sulfa drugs work by:

b. Competing with PABA in folic acid synthesis

A drug that kills bacteria directly is described as:

b. Bactericidal

Which antibiotic is known for causing “gray baby syndrome”?

c. Chloramphenicol

Vancomycin is primarily used against:

b. MRSA (methicillin-resistant Staph. aureusa)

Quinolones like ciprofloxacin work by:

c. Inhibiting DNA gyrase

Which antiviral drug is a nucleoside analog used against herpes viruses?

a. Acyclovir

AZT (zidovudine) is used to treat HIV by:

b. Inhibiting reverse transcriptase

Interferons are:

b. Antiviral proteins produced by host toxins

Bacteria that survive antibiotic treatment due to genetic characteristics are called:

b. Persister cells

Which mechanism involves enzymes that break down antibiotics?

c. Drug inactivation

MRSA stands for:

b. Methicillin-resistant Staphylococcus aureus

Which of these contributes to antibiotic resistance?

d. All of the above

When two drugs work together producing an effect greater than either alone, this is called:

b. Synergism

Which drug combination might show antagonism?

a. Bactericidal + bacteriostatic drug

The lowest concentrations of drug that inhibits visible growth is called:

a. MIC (minimum inhibitory concentration)

Penicillin

Inhibits cell wall synthesis

Tetracycline

Inhibits protein synthesis (30S subunit)

Ciprofloxacin

Inhibits nucleic acid synthesis (DNA gyrase)

Polymyxin B

Damages plasma membrane

Rifampin

Inhibits RNA synthesis (RNA polymerase)

Erythromycin

Inhibits protein synthesis (50S subunit)

Sulfamethoxazole

Inhibits folic acid synthesis (anti-metabolite)

Vancomycin

Inhibits cell wall synthesis

Chloramphenicol

Inhibits protein synthesis (50S subunit, peptide bond formation)

Bacitracin

Inhibits cell wall synthesis (peptidoglycan transport)