Bacteriology: Salmonella: 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: Salmonella

Sample item

A child with sickle cell disease has fever and bone pain, and bone aspirate grows a motile Gram-negative bacillus that is non-lactose fermenting and produces H2S. Which organism is most characteristically associated?

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

The answer and the reasoning

A. Non-typhoidal Salmonella

Sickle cell disease predisposes to osteomyelitis by Salmonella, probably through bone infarcts and splenic dysfunction, besides Staphylococcus aureus. The H2S positive non-lactose fermenter points to Salmonella. Puncture wounds through shoes link to Pseudomonas.

Option by option

  • A. Non-typhoidal Salmonella (correct)

    Correct. H2S-producing, non-lactose fermenting bacilli in sickle cell osteomyelitis suggest Salmonella.

  • B. Pseudomonas aeruginosa

    Pseudomonas is oxidase positive and does not produce H2S in this way.

  • C. Haemophilus influenzae type b

    Hib is a fastidious coccobacillus needing factors X and V.

  • D. Staphylococcus epidermidis

    S. epidermidis is a Gram-positive coccus associated with prosthetic material.

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 A, Non-typhoidal Salmonella. Sickle cell disease predisposes to osteomyelitis by Salmonella, probably through bone infarcts and splenic dysfunction, besides Staphylococcus aureus.

Why is "Pseudomonas aeruginosa" not the answer?

Pseudomonas is oxidase positive and does not produce H2S in this way.

Why is "Haemophilus influenzae type b" not the answer?

Hib is a fastidious coccobacillus needing factors X and V.

Why is "Staphylococcus epidermidis" not the answer?

S. epidermidis is a Gram-positive coccus associated with prosthetic material.

What concept does this question test?

It tests Bacteriology: Salmonella in Microbiology. The H2S positive non-lactose fermenter points to Salmonella. Puncture wounds through shoes link to Pseudomonas.

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: Salmonella?

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.