Vancomycin does not belong to which antibiotic class?

Vancomycin does not belong to which antibiotic class?

• A. Beta-lactam
• B. Glycopeptide
• C. Macrolide
• D. Lincosamide

Answer: (A)

The main idea here is distinguishing antibiotics by how they work and their chemical structure. Vancomycin binds to the D-Ala-D-Ala end of peptidoglycan precursors, blocking the final steps of cell-wall cross-linking. That mechanism is characteristic of glycopeptides, not beta-lactams. Beta-lactam antibiotics have a beta-lactam ring and inhibit penicillin-binding proteins to stop cell-wall synthesis, but they work through a different chemical pathway. Macrolides and lincosamides, meanwhile, inhibit bacterial protein synthesis at the 50S ribosomal subunit. So vancomycin does not belong to the beta-lactam class.

The main idea here is distinguishing antibiotics by how they work and their chemical structure. Vancomycin binds to the D-Ala-D-Ala end of peptidoglycan precursors, blocking the final steps of cell-wall cross-linking. That mechanism is characteristic of glycopeptides, not beta-lactams. Beta-lactam antibiotics have a beta-lactam ring and inhibit penicillin-binding proteins to stop cell-wall synthesis, but they work through a different chemical pathway. Macrolides and lincosamides, meanwhile, inhibit bacterial protein synthesis at the 50S ribosomal subunit. So vancomycin does not belong to the beta-lactam class.