Question

Vancomycin is

• A. Glycopeptide antibiotic
• B. Oxazolidinone antibiotic
• C. Lincosamide antibiotic
• D. Aminoglycoside antibiotic

Hint:

Antibiotics are grouped into chemical classes based on their structure, and each class has a typical mechanism of action. Identifying the class helps predict the drug's spectrum and side effects.

Answer 1

The Correct Option is A

Step 1: What is Vancomycin?
Vancomycin is an important antibiotic used to treat serious gram-positive infections, especially MRSA (Methicillin-resistant Staphylococcus aureus) and Clostridioides difficile colitis.

Step 2: How Vancomycin works.
Vancomycin inhibits bacterial cell wall synthesis by binding to the D-Ala-D-Ala terminal of peptidoglycan precursors. This prevents the cross-linking (transpeptidation) needed to build a strong cell wall, leading to bacterial cell death.

Step 3: Chemical classification - Glycopeptide.
Vancomycin belongs to the glycopeptide antibiotic class. Glycopeptides are large complex molecules containing a glycosylated cyclic peptide. Other glycopeptides include teicoplanin and dalbavancin.

Step 4: Eliminate other options.
Oxazolidinones (like linezolid) inhibit protein synthesis at the 50S ribosome. Lincosamides (like clindamycin) also inhibit 50S ribosome. Aminoglycosides (like gentamicin) inhibit protein synthesis at the 30S ribosome. None of these apply to Vancomycin.

Step 5: Clinical importance of this classification.
Vancomycin's glycopeptide structure makes it too large to penetrate gram-negative bacteria's outer membrane, which is why it works only against gram-positive organisms.

Step 6: Conclusion.
Vancomycin is classified as a Glycopeptide antibiotic.
Answer: Option (1) — Glycopeptide antibiotic