Which antimicrobial agent inhibits cell wall synthesis?

Which antimicrobial agent inhibits cell wall synthesis?

• A. Clindamycin
• B. Gentamicin
• C. Nalidixic acid
• D. Vancomycin

Answer: (D)

Vancomycin stops cell wall construction by binding to the terminal D-Ala-D-Ala residues of the growing peptidoglycan chain. This binding blocks the enzymes that would normally cross-link the wall material, so the peptidoglycan network isn’t properly formed. Without a strong, intact cell wall, the bacterial cell can’t withstand osmotic pressure and lysis occurs. This mechanism specifically targets the wall-building process, which is why vancomycin is classified as a cell wall synthesis inhibitor. The other drugs act on different targets—protein synthesis or DNA replication—so they do not inhibit the cell wall.

Vancomycin stops cell wall construction by binding to the terminal D-Ala-D-Ala residues of the growing peptidoglycan chain. This binding blocks the enzymes that would normally cross-link the wall material, so the peptidoglycan network isn’t properly formed. Without a strong, intact cell wall, the bacterial cell can’t withstand osmotic pressure and lysis occurs. This mechanism specifically targets the wall-building process, which is why vancomycin is classified as a cell wall synthesis inhibitor. The other drugs act on different targets—protein synthesis or DNA replication—so they do not inhibit the cell wall.