Bacteriology: psittacosis: 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: psittacosis

Sample item

A pigeon breeder presents with fever, headache, dry cough and splenomegaly. Chest radiograph shows patchy consolidation. Gram stain of sputum shows no bacteria. Which drug is the treatment of choice?

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

The answer and the reasoning

D. Doxycycline

Chlamydia psittaci (psittacosis) is acquired by inhaling dried bird droppings and causes atypical pneumonia with systemic features. It is an obligate intracellular bacterium, so tetracyclines such as doxycycline, which penetrate cells, are the treatment of choice, with macrolides as alternatives. Beta-lactams and aminoglycosides do not work well against intracellular chlamydiae.

Option by option

  • A. Ceftriaxone

    Ceftriaxone does not eradicate intracellular chlamydial infection.

  • B. Amoxicillin

    Beta-lactams like amoxicillin are ineffective against intracellular chlamydiae.

  • C. Gentamicin

    Aminoglycosides penetrate cells poorly and are ineffective.

  • D. Doxycycline (correct)

    Correct. Doxycycline reaches intracellular chlamydiae and is the drug of choice.

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, Doxycycline. Chlamydia psittaci (psittacosis) is acquired by inhaling dried bird droppings and causes atypical pneumonia with systemic features.

Why is "Ceftriaxone" not the answer?

Ceftriaxone does not eradicate intracellular chlamydial infection.

Why is "Amoxicillin" not the answer?

Beta-lactams like amoxicillin are ineffective against intracellular chlamydiae.

Why is "Gentamicin" not the answer?

Aminoglycosides penetrate cells poorly and are ineffective.

What concept does this question test?

It tests Bacteriology: psittacosis in Microbiology. It is an obligate intracellular bacterium, so tetracyclines such as doxycycline, which penetrate cells, are the treatment of choice, with macrolides as alternatives. Beta-lactams and aminoglycosides do not work well against intracellular chlamydiae.

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 Bacteriology: psittacosis?

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.