Question

Which of the following compounds is not generally elaborated by staphylococcal species?

• A. Verotoxin
• B. Enterotoxin
• C. Hemolysin
• D. Coagulase

Hint:

Remember to associate toxins with their specific bacterial groups:
- Verotoxin (Shiga-like toxin) $\rightarrow$ Gram-negative rods (E. coli, Shigella).
- Enterotoxin, Hemolysin, Coagulase $\rightarrow$ Gram-positive cocci (Staphylococcus).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Staphylococcus aureus is a major foodborne pathogen that produces a variety of virulence factors, including enzymes and toxins, during its growth.
Identifying the source of different bacterial toxins is essential for diagnosing foodborne illnesses.
Detailed Explanation:
Let us analyze the extracellular compounds produced by Staphylococcus species:
1. Enterotoxins: Staphylococcus aureus strains produce heat-stable staphylococcal enterotoxins (such as SEA, SEB, SEC, and SED).
These toxins are superantigens that cause staphylococcal food poisoning when ingested.
2. Hemolysins: Staphylococci produce cytolytic toxins (alpha, beta, gamma, and delta-hemolysins) that target cell membranes and lyse red blood cells, which is visible as hemolysis on blood agar plates.
3. Coagulase: This enzyme clots blood plasma by converting fibrinogen to fibrin.
It is a key virulence factor and the primary diagnostic marker used to identify pathogenic Staphylococcus aureus (coagulase-positive).
Now let us analyze Verotoxin (also known as Shiga-like toxin):
Verotoxins are cytotoxins that inhibit protein synthesis in host cells by damaging the 28S ribosomal RNA of the 60S ribosomal subunit.
These toxins are produced by Shiga toxin-producing Escherichia coli (STEC/EHEC), such as the O157:H7 strain, and by Shigella dysenteriae.
They are not produced by Staphylococcus species.

Step 2: Final Answer:
Verotoxin is the compound not elaborated by staphylococcal species.