Genital mycoplasmas: Ureaplasma: 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.

Try it

Microbiology · Genital mycoplasmas: Ureaplasma

Sample item

A 26-year-old man has urethritis with mucoid discharge. Gram stain shows no organisms, and NAAT is negative for Neisseria gonorrhoeae and Chlamydia trachomatis. A culture on special agar grows tiny colonies of an organism that lacks a cell wall and hydrolyses urea. Which organism is responsible?

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

The answer and the reasoning

B. Ureaplasma urealyticum

Ureaplasma urealyticum lacks a cell wall, so it does not stain with Gram stain or respond to beta-lactams, and it splits urea. It causes non-gonococcal urethritis and is treated with doxycycline or azithromycin. Trichomonas is a flagellate seen on wet mount.

Option by option

  • A. Haemophilus ducreyi

    Haemophilus ducreyi causes chancroid, a painful genital ulcer, not urethritis.

  • B. Ureaplasma urealyticum (correct)

    Correct. Absent cell wall plus urease activity identifies Ureaplasma.

  • C. Treponema pallidum

    Treponema pallidum causes syphilis and cannot be cultured on artificial media.

  • D. Trichomonas vaginalis

    Trichomonas vaginalis is a motile protozoan seen on wet mount and does not grow as wall-less bacterial colonies.

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, Ureaplasma urealyticum. Ureaplasma urealyticum lacks a cell wall, so it does not stain with Gram stain or respond to beta-lactams, and it splits urea.

Why is "Haemophilus ducreyi" not the answer?

Haemophilus ducreyi causes chancroid, a painful genital ulcer, not urethritis.

Why is "Treponema pallidum" not the answer?

Treponema pallidum causes syphilis and cannot be cultured on artificial media.

Why is "Trichomonas vaginalis" not the answer?

Trichomonas vaginalis is a motile protozoan seen on wet mount and does not grow as wall-less bacterial colonies.

What concept does this question test?

It tests Genital mycoplasmas: Ureaplasma in Microbiology. It causes non-gonococcal urethritis and is treated with doxycycline or azithromycin. Trichomonas is a flagellate seen on wet mount.

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 Genital mycoplasmas: Ureaplasma?

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.