What is the main mechanism of action of bacitracin?

What is the main mechanism of action of bacitracin?

• A. Inhibits PGN
• B. Inhibits protein synthesis
• C. Inhibits DNA replication
• D. Inhibits RNA synthesis

Answer: (A)

Bacitracin blocks bacterial growth by stopping cell wall synthesis. It does this by targeting the lipid carrier bactoprenol and preventing its dephosphorylation, so bactoprenol cannot recycle to shuttle peptidoglycan precursors across the cytoplasmic membrane. Without the ability to transport these building blocks, peptidoglycan synthesis halts, weakening the cell wall and leading to lysis in actively growing bacteria. This mechanism is about inhibiting the formation of the cell wall (peptidoglycan), not protein, DNA, or RNA synthesis, which is why the other options don’t fit. In clinical use, bacitracin is typically applied topically because systemic administration can be nephrotoxic, and it’s especially effective against Gram-positive organisms due to greater exposure of the cell wall.

Bacitracin blocks bacterial growth by stopping cell wall synthesis. It does this by targeting the lipid carrier bactoprenol and preventing its dephosphorylation, so bactoprenol cannot recycle to shuttle peptidoglycan precursors across the cytoplasmic membrane. Without the ability to transport these building blocks, peptidoglycan synthesis halts, weakening the cell wall and leading to lysis in actively growing bacteria. This mechanism is about inhibiting the formation of the cell wall (peptidoglycan), not protein, DNA, or RNA synthesis, which is why the other options don’t fit. In clinical use, bacitracin is typically applied topically because systemic administration can be nephrotoxic, and it’s especially effective against Gram-positive organisms due to greater exposure of the cell wall.