Which of the following drugs specifically targets bacterial cell walls that contain mycolic acid?

• A. Ciprofloxacin
• B. Isoniazid
• C. Penicillin
• D. Vancomycin

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the structure of bacterial cell walls and the significance of mycolic acid. Mycolic acid is a long fatty acid found in the cell walls of certain bacteria, notably Mycobacterium species, which cause diseases like tuberculosis.
2. Step 2: Review the mechanism of action of each drug option. Ciprofloxacin inhibits DNA gyrase, affecting DNA replication; Penicillin and Vancomycin target peptidoglycan synthesis in typical bacterial cell walls.
3. Step 3: Recognize that drugs targeting mycolic acid specifically interfere with the synthesis or integrity of the mycolic acid layer, which is unique to mycobacteria and not present in most other bacteria.
4. Step 4: Identify that Isoniazid is known to inhibit the synthesis of mycolic acid, thereby disrupting the cell wall of mycobacteria and making it effective against bacteria with mycolic acid-containing cell walls.
5. Step 5: Conclude that among the options, Isoniazid is the drug that specifically targets bacterial cell walls containing mycolic acid, differentiating it from the other drugs listed.