Question

A characteristic cysteine loop in the structure of Enterotoxin is seen in the toxin produced by _______

• A. Salmonella
• B. Bacillus
• C. Yersinia
• D. Staphylococcus

Hint:

This disulfide cysteine loop makes Staphylococcal enterotoxins highly stable, meaning they can remain active in food even after thermal processing kills the vegetative cells.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Bacterial enterotoxins are globular proteins with specific tertiary structures that enable them to bind to host cells and resist enzymatic digestion.

Step 2: Detailed Explanation:
Staphylococcal Enterotoxins (SEs), produced by Staphylococcus aureus, are a family of major foodborne toxins.
A key structural feature of these enterotoxins is a highly conserved internal disulfide loop (formed by a disulfide bond between two cysteine residues).
This "cysteine loop" is critical for maintaining the heat and protease resistance of the toxin, allowing it to survive cooking and stomach acids to cause food poisoning.

Step 3: Final Answer:
The characteristic cysteine loop is found in enterotoxins produced by Staphylococcus.