Bacteriology: Haemophilus ducreyi: 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: Haemophilus ducreyi

Sample item

A man has multiple painful genital ulcers with ragged undermined edges and a tender suppurative inguinal bubo. Smear shows Gram-negative coccobacilli in parallel chains. What is the most likely diagnosis?

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

The answer and the reasoning

D. Chancroid

Haemophilus ducreyi causes painful soft ulcers with suppurative nodes, and organisms appear like a school of fish. Syphilitic chancre is painless and indurated. Donovanosis causes painless beefy ulcers without nodes, and LGV causes a transient ulcer with buboes.

Option by option

  • A. Primary syphilis

    Syphilitic chancre is single, painless and indurated.

  • B. Donovanosis

    Donovanosis is painless with Donovan bodies and little lymphadenopathy.

  • C. Lymphogranuloma venereum

    LGV has a small transient ulcer followed by buboes and Chlamydia trachomatis serovars.

  • D. Chancroid (correct)

    Correct. Painful ulcers with suppurative buboes and school-of-fish smear is chancroid.

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 D, Chancroid. Haemophilus ducreyi causes painful soft ulcers with suppurative nodes, and organisms appear like a school of fish.

Why is "Primary syphilis" not the answer?

Syphilitic chancre is single, painless and indurated.

Why is "Donovanosis" not the answer?

Donovanosis is painless with Donovan bodies and little lymphadenopathy.

Why is "Lymphogranuloma venereum" not the answer?

LGV has a small transient ulcer followed by buboes and Chlamydia trachomatis serovars.

What concept does this question test?

It tests Bacteriology: Haemophilus ducreyi in Microbiology. Syphilitic chancre is painless and indurated. Donovanosis causes painless beefy ulcers without nodes, and LGV causes a transient ulcer with buboes.

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: Haemophilus ducreyi?

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.