Aminoglycosides belong to which antibiotic class?

• A. Macrolides
• B. Aminoglycosides
• C. Tetracyclines
• D. Lincosamides

Answer: (B)

Aminoglycosides are a distinct group of antibiotics defined by both their chemical structure and their mechanism of action. They contain amino-sugar components and work by binding to the 30S subunit of bacterial ribosomes, causing misreading of the genetic code and blocking the initiation of protein synthesis. This leads to a bactericidal effect, unlike many other antibiotic classes that are often bacteriostatic. This mechanism sets them apart from the other options: macrolides target the 50S subunit and inhibit translocation, tetracyclines also target the 30S but block tRNA binding, and lincosamides bind to 50S to interfere with peptide bond formation. Examples include gentamicin, amikacin, tobramycin, and streptomycin, and their use is typical for serious Gram-negative infections, with consideration for potential nephrotoxicity and ototoxicity.