Question

which of the following causes damage to the nucleic acids? choose all that applies.
ciprofloxacin
levofloxacin
rifamycin
methicillin

Explanation:

• Ciprofloxacin and Levofloxacin are fluoroquinolones. They inhibit DNA gyrase (topoisomerase II) and topoisomerase IV, which are essential for bacterial DNA replication, transcription, repair, and recombination. By interfering with these enzymes, they cause damage to bacterial nucleic acids (DNA).
• Rifamycin (e.g., rifampin) inhibits bacterial RNA polymerase. RNA polymerase is crucial for the synthesis of RNA from DNA (transcription). By blocking this enzyme, it disrupts the normal flow of genetic information from DNA to RNA, effectively causing damage at the nucleic - acid level (as the normal function of DNA in directing RNA synthesis is impaired).
• Methicillin is a penicillin - like antibiotic. It acts by inhibiting the synthesis of the bacterial cell wall (by targeting penicillin - binding proteins involved in peptidoglycan synthesis). It does not directly target nucleic acids.

Answer:

Ciprofloxacin, Levofloxacin, Rifamycin.