Which antibiotic class is known to inhibit bacterial DNA synthesis?

The sulfonamide class of antibiotics is known to inhibit bacterial DNA synthesis primarily by interfering with the synthesis of folic acid, which is essential for the production of nucleic acids. Sulfonamides mimic para-aminobenzoic acid (PABA), a substrate required for the bacterial enzyme dihydropteroate synthase. By competitively inhibiting this enzyme, sulfonamides effectively prevent the formation of folate, thus disrupting DNA synthesis and ultimately inhibiting bacterial growth.

This mechanism is distinct from that of other antibiotic classes mentioned. Cephalosporins and tetracyclines target the bacterial cell wall synthesis and protein synthesis, respectively, without directly interfering with DNA synthesis. Aminoglycosides also primarily function by inhibiting protein synthesis. Therefore, the unique action of sulfonamides in impacting folate synthesis is what makes this antibiotic class specifically effective in inhibiting bacterial DNA synthesis.