Final answer:
Fluoroquinolones, including nalidixic acid, ciprofloxacin, and levofloxacin, block nucleotide synthesis by inhibiting DNA gyrase activity in bacteria, making them highly effective for treating various infections. Among the provided options, quinolones are the correct answer.
Step-by-step explanation:
The antibiotics that block the synthesis of nucleotides are fluoroquinolones. Specifically, within this group, drugs such as nalidixic acid, ciprofloxacin, and levofloxacin inhibit the activity of bacterial DNA gyrase, blocking DNA replication which is essential for nucleotide synthesis. This action makes fluoroquinolones effective against a broad spectrum of bacteria.
They are commonly used to treat various infections, including urinary tract infections, respiratory infections, abdominal infections, and skin infections. On the other hand, rifampin, a semisynthetic member of the rifamycin family, functions by blocking bacterial RNA polymerase activity, thus affecting RNA transcription but not directly nucleotide synthesis.
From the given options, therefore, D. Quinolones is the correct choice as the class of antibiotics that blocks the synthesis of nucleotides.