Bacteriology: Clostridioides difficile: practice question

A Microbiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Microbiology · Bacteriology: Clostridioides difficile

Sample item

A patient develops watery diarrhoea 5 days after starting clindamycin. Stool is positive for glutamate dehydrogenase and toxin B gene PCR, and colonoscopy shows yellow plaques. What is a recommended drug for an initial episode?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Oral fidaxomicin or vancomycin

Initial C. difficile infection is treated with oral fidaxomicin or oral vancomycin, and the offending antibiotic is stopped. Antimotility drugs are avoided because they risk toxic megacolon. Gentamicin has no role.

Option by option

  • A. Intravenous gentamicin

    Intravenous gentamicin does not reach the colon lumen and is not active.

  • B. Oral fidaxomicin or vancomycin (correct)

    Correct. Oral fidaxomicin or vancomycin is the treatment of an initial episode.

  • C. Oral loperamide

    Loperamide can precipitate toxic megacolon.

  • D. Oral metronidazole alone for severe cases in all patients

    Metronidazole is no longer preferred for severe initial infection.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is B, Oral fidaxomicin or vancomycin. Initial C.

Why is "Intravenous gentamicin" not the answer?

Intravenous gentamicin does not reach the colon lumen and is not active.

Why is "Oral loperamide" not the answer?

Loperamide can precipitate toxic megacolon.

Why is "Oral metronidazole alone for severe cases in all patients" not the answer?

Metronidazole is no longer preferred for severe initial infection.

What concept does this question test?

It tests Bacteriology: Clostridioides difficile in Microbiology. difficile infection is treated with oral fidaxomicin or oral vancomycin, and the offending antibiotic is stopped. Antimotility drugs are avoided because they risk toxic megacolon. Gentamicin has no role.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Bacteriology: Clostridioides difficile?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.