Aminoglycosides generally have better coverage against which type of bacteria?

• A. Gram Negative
• B. Gram Positive
• C. Fungi
• D. Viruses

Answer: (A)

Aminoglycosides are most effective against aerobic Gram-negative bacteria. Their uptake into bacterial cells requires oxygen, so they are less active against anaerobes and most Gram-positive organisms. They work by binding to the 30S ribosomal subunit to disrupt protein synthesis, producing a bactericidal effect that is particularly strong against Gram-negative rods (like Enterobacterales and Pseudomonas). They have limited activity on fungi and viruses, and any significant Gram-positive activity is usually only in synergy with a cell-wall–active agent, not as standalone coverage. Therefore, their general strength lies in Gram-negative coverage.