Question

Which of the following is NOT correct with respect to Staphylococcus aureus?

• A. It survives water activity as low as 0.85
• B. It produces neurotoxins
• C. It is halotolerant
• D. It produces thermostable enterotoxins

Hint:

Staphylococcal Characteristics:
$a_w$ tolerance = Down to 0.85.
Salt tolerance = Up to 10--15% NaCl.
Toxin = THERMOSTABLE ENTEROTOXINS (Causes vomiting/diarrhea).
Neurotoxins = Clostridium botulinum.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Bacterial food toxicology: Staphylococcus aureus is an osmotolerant, halotolerant bacterium producing heat-stable gastrointestinal enterotoxins (SEA--SEE); neurotoxins are produced by Clostridium botulinum.
Key Formula or Approach:
\[ \textit{Staphylococcus aureus} \xrightarrow{\text{Enterotoxins A--E}} \text{Gastroenteritis (Emesis/Vomiting)} \quad [\mathbf{NOT \text{ Neurotoxins}}] \]

Step 2: Detailed Explanation:
Evaluating physiological and toxicological characteristics of {Staphylococcus aureus:
1. Water Activity Tolerance (A): Exceptionally xerotolerant; grows aerobically down to $a_w = 0.85$ (and $a_w = 0.86$ anaerobically). (Correct).
2. Halotolerance (C): Highly osmotolerant and halotolerant; grows in up to $10\% - 15\%\text{ NaCl}$ (e.g., in salted butter/cheese). (Correct).
3. Thermostable Enterotoxins (D): Synthesizes extracellular heat-stable enterotoxins (SEA, SEB, SEC, SED, SEE) that resist boiling at $100^\circ ext{C}$ for 30 minutes, inducing acute emetic gastroenteritis. (Correct).
4. Neurotoxin Production (B): S. aureus produces Gastrointestinal Enterotoxins, NOT neurotoxins. (Potent foodborne neurotoxins are produced by {Clostridium botulinum). Therefore, statement B is NOT correct.

Step 3: Final Answer:
Thus, 'It produces neurotoxins' is NOT correct, corresponding to option (B).