This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
Metronidazole is used for all 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 Metronidazoleo It has broad spectrum antiprotozoal activity against trichomonas, E. histolytica and G lamblia.o It is also active against many anaerobic bacteria,o It does not affect aerobic bacteria.o It acts by inhibiting pyruvate : Ferredoxin oxidoreductase (PFOR) enzyme pathway of pyruvate oxidation in anaerobes.o In protozoa the mechanism of action is different, i.e. damage to DNA.o Metronidazole is a nitroimdazole, nitro group is activated by reduction to form reactive cytotoxic product that damages the DNA.o It inhibit cell mediated immunity to induce mutagenesis and causes radiosensitization,o Adverse effects - see above question,o Uses1. Amoebiasis5. Pseudomembranous enterocolitis.2. Giardiasis6. Ulcerative gingivitis, trench mouth.3. Trichomonas vaginitis7. H. pylori gastritis, peptic ulcer.4. Anaerobic bacterial infection