Which of the following antiviral drug most commonly used drug for prevention and treatment of CMV infections in the immunocompromised patients?

Correct Answer: A

Rationale: Rationale: 1. Ganciclovir is the preferred antiviral for CMV infections due to its effectiveness against CMV. 2. It works by inhibiting viral DNA polymerase, stopping viral replication. 3. Indinavir is a protease inhibitor used for HIV, not CMV. 4. Amantadine is used for influenza A virus, not CMV. 5. Foscarnet is an alternative for CMV if ganciclovir is not tolerated.

Correct Answer: D

Rationale: The correct answer is D because both statements (A and B) are accurate. A: Metronidazole is a first-line drug for amoebic dysentery and liver abscess due to its efficacy against Entamoeba histolytica. B: Metronidazole is a prodrug that gets activated to form nitro intermediates, which bind DNA and disrupt anaerobic microbial replication. Therefore, option D is correct as both A and B provide accurate information about metronidazole. Option C is incorrect as metronidazole is not specifically targeted to eradicating amoebic cysts from the colon.

Correct Answer: D

Rationale: The correct answer is D: Escherichia coli. E. coli is notorious for developing antimicrobial resistance rapidly due to its ability to acquire resistance genes through plasmid exchange and mutation. This bacterium is commonly found in the gut of humans and animals, leading to frequent exposure to antibiotics. On the other hand, choices A, B, and C are less likely to develop resistance as rapidly as E. coli due to their lower frequency of exposure to antibiotics and differences in genetic makeup. Streptococcus pyogenes is susceptible to penicillin, Meningococcus has shown susceptibility to several antibiotics, and Treponema pallidum has limited exposure to antibiotics due to its unique nature as the causative agent of syphilis.

Correct Answer: C

Rationale: Rationale: The correct answer is C: Hydrochlorothiazide. It is a thiazide diuretic that reduces calcium excretion, preventing stone formation. Furosemide (A) and spironolactone (B) do not target calcium excretion specifically. Acetazolamide (D) is a carbonic anhydrase inhibitor and not commonly used for calcium stones.

Correct Answer: C

Rationale: The correct answer is C: Hydrochlorothiazide. Hydrochlorothiazide is a thiazide diuretic that works by reducing calcium excretion and increasing uric acid levels, which can lead to gout attacks in susceptible individuals. Furosemide (choice A) is a loop diuretic that does not increase uric acid levels. Spironolactone (choice B) is a potassium-sparing diuretic and does not affect calcium or uric acid levels significantly. Triamterene (choice D) is also a potassium-sparing diuretic and does not impact calcium or uric acid levels in the same way as hydrochlorothiazide.