Which antibiotic does NOT target the bacterial cell wall?

Which antibiotic does NOT target the bacterial cell wall?

• A. Bacitracin
• B. Penicillins
• C. Fluoroquinolones
• D. Cephalosporins

Answer: (C)

Antibiotics that disrupt the bacterial cell wall do so by stopping peptidoglycan synthesis or cross-linking, which weakens the wall and leads to bacterial lysis. Bacitracin blocks the lipid carrier that ferries wall-building subunits to the wall. Penicillins and cephalosporins inhibit penicillin-binding proteins that perform cross-linking of peptidoglycan. Fluoroquinolones, in contrast, do not affect the cell wall; they inhibit DNA gyrase and topoisomerase IV, enzymes needed for DNA replication. So the antibiotic that does not target the cell wall is the one that interferes with DNA processes rather than wall construction.

Antibiotics that disrupt the bacterial cell wall do so by stopping peptidoglycan synthesis or cross-linking, which weakens the wall and leads to bacterial lysis. Bacitracin blocks the lipid carrier that ferries wall-building subunits to the wall. Penicillins and cephalosporins inhibit penicillin-binding proteins that perform cross-linking of peptidoglycan. Fluoroquinolones, in contrast, do not affect the cell wall; they inhibit DNA gyrase and topoisomerase IV, enzymes needed for DNA replication. So the antibiotic that does not target the cell wall is the one that interferes with DNA processes rather than wall construction.