General microbiology: biosafety levels: 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 · General microbiology: biosafety levels

Sample item

A tertiary hospital laboratory plans to start liquid culture and drug susceptibility testing of Mycobacterium tuberculosis from sputum. Which minimum biosafety level and practice is appropriate?

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

The answer and the reasoning

A. Biosafety level 3 with a biosafety cabinet and respiratory protection

Manipulating cultures of M. tuberculosis generates infectious aerosols, so culture and drug susceptibility testing are done in a BSL-3 laboratory with controlled airflow, a class II biosafety cabinet and respirators. Direct smear microscopy can be done at BSL-2. BSL-4 is reserved for agents such as Ebola virus.

Option by option

  • A. Biosafety level 3 with a biosafety cabinet and respiratory protection (correct)

    Correct. Aerosol-generating culture work needs BSL-3 containment.

  • B. Biosafety level 1 on an open bench

    Biosafety level 1 is for well-characterised agents that do not cause disease in healthy adults.

  • C. Biosafety level 4 with a positive-pressure suit

    Biosafety level 4 is for exotic agents with no treatment, such as Ebola and Nipah viruses.

  • D. Biosafety level 2 without a cabinet

    Biosafety level 2 is adequate for smear microscopy but not for culture of tubercle bacilli.

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, Biosafety level 3 with a biosafety cabinet and respiratory protection. Manipulating cultures of M.

Why is "Biosafety level 1 on an open bench" not the answer?

Biosafety level 1 is for well-characterised agents that do not cause disease in healthy adults.

Why is "Biosafety level 4 with a positive-pressure suit" not the answer?

Biosafety level 4 is for exotic agents with no treatment, such as Ebola and Nipah viruses.

Why is "Biosafety level 2 without a cabinet" not the answer?

Biosafety level 2 is adequate for smear microscopy but not for culture of tubercle bacilli.

What concept does this question test?

It tests General microbiology: biosafety levels in Microbiology. tuberculosis generates infectious aerosols, so culture and drug susceptibility testing are done in a BSL-3 laboratory with controlled airflow, a class II biosafety cabinet and respirators. Direct smear microscopy can be done at BSL-2. BSL-4 is reserved for agents such as Ebola virus.

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 General microbiology: biosafety levels?

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.