Thanatology: gas-forming organism in putrefaction: practice question

A Forensic 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.

Try it

Forensic Medicine · Thanatology: gas-forming organism in putrefaction

Sample item

At autopsy of a decomposing body the liver is spongy with gas bubbles, giving a foamy appearance on cutting. Which organism is mainly responsible for this gas formation?

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

The answer and the reasoning

D. Clostridium perfringens

Clostridium perfringens (welchii) is an anaerobic gut organism that spreads through the blood after death and ferments tissue to form gas. This produces the foamy or bubbly liver and the bloating of putrefaction.

Option by option

  • A. Staphylococcus aureus

    Staphylococcus aureus is a pus-forming organism and not a main gas former.

  • B. Salmonella typhi

    Salmonella typhi causes enteric fever and is not a major gas producer.

  • C. Streptococcus pyogenes

    Streptococcus pyogenes causes suppurative and invasive infections, not the typical postmortem gas.

  • D. Clostridium perfringens (correct)

    Correct. This anaerobe produces large volumes of gas in dead tissue.

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 Forensic Medicine questions

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is D, Clostridium perfringens. Clostridium perfringens (welchii) is an anaerobic gut organism that spreads through the blood after death and ferments tissue to form gas.

Why is "Staphylococcus aureus" not the answer?

Staphylococcus aureus is a pus-forming organism and not a main gas former.

Why is "Salmonella typhi" not the answer?

Salmonella typhi causes enteric fever and is not a major gas producer.

Why is "Streptococcus pyogenes" not the answer?

Streptococcus pyogenes causes suppurative and invasive infections, not the typical postmortem gas.

What concept does this question test?

It tests Thanatology: gas-forming organism in putrefaction in Forensic Medicine. This produces the foamy or bubbly liver and the bloating of putrefaction.

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 Thanatology: gas-forming organism in putrefaction?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic 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.