Bacteriology: Streptococcus gallolyticus endocarditis: 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: Streptococcus gallolyticus endocarditis

Sample item

A 65-year-old man has fever for 3 weeks and a new murmur. Two of three blood culture sets grow Gram-positive cocci that are bile-esculin positive but do not grow in 6.5% sodium chloride, and echocardiography shows a mitral vegetation. Besides starting antibiotics, which investigation is most appropriate next?

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

The answer and the reasoning

B. Colonoscopy

A bile-esculin-positive, salt-intolerant group D coccus is a non-enterococcal group D streptococcus, namely Streptococcus gallolyticus (formerly S. bovis). Bacteraemia and endocarditis with this organism are strongly associated with colonic adenomas and carcinoma, so colonoscopy is advised after the infection is treated or stabilised.

Option by option

  • A. Bronchoscopy

    Bronchoscopy has no link with this organism and is not indicated.

  • B. Colonoscopy (correct)

    Correct. Colonic neoplasia is the key association with this organism.

  • C. Renal biopsy

    Renal biopsy is not indicated, as immune-complex glomerulonephritis if present is managed clinically and does not explain the organism.

  • D. Cystoscopy

    Cystoscopy has no established link with S. gallolyticus bacteraemia.

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, Colonoscopy. A bile-esculin-positive, salt-intolerant group D coccus is a non-enterococcal group D streptococcus, namely Streptococcus gallolyticus (formerly S.

Why is "Bronchoscopy" not the answer?

Bronchoscopy has no link with this organism and is not indicated.

Why is "Renal biopsy" not the answer?

Renal biopsy is not indicated, as immune-complex glomerulonephritis if present is managed clinically and does not explain the organism.

Why is "Cystoscopy" not the answer?

Cystoscopy has no established link with S. gallolyticus bacteraemia.

What concept does this question test?

It tests Bacteriology: Streptococcus gallolyticus endocarditis in Microbiology. bovis). Bacteraemia and endocarditis with this organism are strongly associated with colonic adenomas and carcinoma, so colonoscopy is advised after the infection is treated or stabilised.

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: Streptococcus gallolyticus endocarditis?

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.