All of the following antibacterial agents acts by inhibiting cell wall synthesis, except -
Carbapenems
Monobactams
Cephamycins
Nitrofurantoin
Ans. is 'd' i.e., Nitrofurantoin Nitrofurantoin acts by generation of highly reactive intermediates which damage DNA. It does not inhibit cell wall synthesis. Drugs inhibiting cell wall synthesis - beta-lactarn antibiotics (Penicillin, Cephalosporins, monobactoms, Carbapenems), Cycloserine, bacitracin, vancomycin, fosfomycin. o Cause leakage from cell membrane - Polypeptides (Polymyxins, Colistin, tyrothricin), Polyenes (Amphotericin B, Nystatin, Hamycin), Azoles (Ketoconazole, fluconazole, intraconazole) o Inhibit protein synthesis - Tetracyclines, Chloramphenicol, Erythromycin, Clindamycin, Linezolid. o Cause misreading of m-RNA code and affect permeability- Aminoglycosides. Inhibit DNA gyrase - Nalidixic acid and fluoroquinolones. Interfere with DNA function - Rifampin, metronidazole. Interfere with DNA synthesis - Acyclovir, zidovudin. o Interfere with intermediary metabolism - Sulfonamide, Sulfones, PAS, trimethoprim, Pyrimethamine, Ethambutol.