What differentiates aminoglycosides from all classes of beta-lactams?

Aminoglycosides are distinct from all classes of beta-lactams primarily because they inhibit protein synthesis. This class of antibiotics achieves its effect by binding to the bacterial ribosome, specifically the 30S subunit, which disrupts the translation of mRNA into proteins. As a result, this interference with protein synthesis can lead to bacterial cell death, particularly against aerobic gram-negative bacteria.

In contrast, beta-lactams, which include penicillins, cephalosporins, and other related compounds, primarily act by inhibiting cell wall synthesis. They target the synthesis of peptidoglycan, a crucial component of the bacterial cell wall, causing osmotic instability and leading to cell lysis. This fundamental difference in mechanisms of action is central to differentiating aminoglycosides from beta-lactams.

The other options do not accurately describe the unique characteristics of aminoglycosides relative to beta-lactams, as they either misattribute functions (such as nucleic acid synthesis or bacteriostatic activity) or mistake the target action (cell wall inhibition). Thus, the specificity of aminoglycosides as protein synthesis inhibitors is what sets them apart from beta-lactams.