Bacillus cereus gastroenteritis — toxin release in food: The exoenterotoxin responsible for one syndrome is released into food chiefly as a consequence of which cellular event?

Introduction / Context:
Bacillus cereus causes two foodborne syndromes: an emetic form (preformed cereulide toxin) and a diarrheal form (enterotoxins). Understanding when and how toxins get into food helps design controls.

Given Data / Assumptions:

• Question targets the process by which an exoenterotoxin is released into food.
• B. cereus is spore-forming and can grow in cooked, cooled, and temperature-abused foods such as rice and sauces.

Concept / Approach:
For the diarrheal-type enterotoxins, one described route into food is through cellular breakdown. Autolysis (self-digestion of bacterial cells) liberates intracellular or periplasm-associated toxin components into the surrounding food matrix.

Step-by-Step Solution:
Associate exoenterotoxin presence in food with late-growth or stationary-phase events.Recognize that autolysis releases intracellular contents, including toxins.Choose ‘‘Cell autolysis’’ as the mechanism consistent with toxin accumulation in food.

Verification / Alternative check:
Food microbiology texts describe liberation of certain B. cereus toxins into foods after growth and autolysis, explaining detection even post-heat treatment.

Why Other Options Are Wrong:

• Cell growth: increases biomass but does not by itself release intracellular toxin.
• Cell permeation: vague and not the canonical explanation.
• Cell damage: non-specific; autolysis is the specific self-degradation process.

Common Pitfalls:
Conflating the emetic cereulide (heat-stable peptide made during food growth) with diarrheal enterotoxins produced in the intestine; the question specifically asks about exoenterotoxin released in food.

Final Answer:
Cell autolysis