Cardiology: culture-negative endocarditis: practice question

A General Medicine 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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General Medicine · Cardiology: culture-negative endocarditis

Sample item

A 30-year-old man with a bicuspid aortic valve and a recent dental extraction has 3 weeks of fever and a new murmur. Routine blood cultures are negative at 48 hours, but with prolonged incubation they grow Gram-negative bacilli after 5 days. Which group of organisms is the usual cause?

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

The answer and the reasoning

C. HACEK group organisms

The HACEK group of slow-growing oral Gram-negative bacilli (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella) causes endocarditis that is slow to show on culture. They are commensals of the mouth and often affect damaged valves after dental procedures.

Option by option

  • A. Klebsiella pneumoniae

    Klebsiella is a rapid grower and an uncommon cause of endocarditis.

  • B. Escherichia coli

    Escherichia coli rarely causes endocarditis and grows quickly in culture.

  • C. HACEK group organisms (correct)

    Correct. HACEK organisms are oral commensals that grow slowly and cause subacute endocarditis on abnormal valves.

  • D. Pseudomonas aeruginosa

    Pseudomonas typically causes endocarditis in people who inject drugs and grows readily.

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 General Medicine questions

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is C, HACEK group organisms. The HACEK group of slow-growing oral Gram-negative bacilli (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella) causes endocarditis that is slow to show on culture.

Why is "Klebsiella pneumoniae" not the answer?

Klebsiella is a rapid grower and an uncommon cause of endocarditis.

Why is "Escherichia coli" not the answer?

Escherichia coli rarely causes endocarditis and grows quickly in culture.

Why is "Pseudomonas aeruginosa" not the answer?

Pseudomonas typically causes endocarditis in people who inject drugs and grows readily.

What concept does this question test?

It tests Cardiology: culture-negative endocarditis in General Medicine. They are commensals of the mouth and often affect damaged valves after dental procedures.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Cardiology: culture-negative endocarditis?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.