This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
All are uses of metronidazole except ? 
Select and explain. 
A. Amoebiasis, B. Giardiasis, C. Trichomonas vaginitis, D. Malaria
D: Malaria
Answer: D: Malaria 
Explanation: Ans. is 'd' i.e., Malaria Metronidazole It has broad spectrum antiprotozoal activity against trichomonas, E. histolytica and G. lamblia. It is also active against many anaerobic bacteria. It does not affect aerobic bacteria. It acts by inhibiting pyruvate : Ferredoxin oxidoreductase (PFOR) enzyme pathway of pyruvate oxidation in anaerobes. In protozoa the mechanism of action is different, i.e. damage to DNA. Metronidazole is a nitroimdazole, nitro group is activated by reduction to form reactive cytotoxic product that damages the DNA. It inhibit cell mediated immunity to induce mutagenesis and causes radiosensitization. Uses Amoebiasis Pseudomembranous enterocolitis. Giardiasis Ulcerative gingivitis, trench mouth. Trichomonas vaginitis H. pylori gastritis, peptic ulcer. Anaerobic bacterial infection