Which of the following best describes a key difference between an enterotoxin and an endotoxin?

• A. Enterotoxins are secreted proteins that target the intestines, while endotoxins are lipopolysaccharides found in the outer membrane of Gram-negative bacteria.
• B. Enterotoxins are only produced by viruses, whereas endotoxins are produced by bacteria.
• C. Enterotoxins are components of the bacterial cell wall, while endotoxins are secreted enzymes that disrupt host cell membranes.
• D. Enterotoxins cause fever, while endotoxins cause diarrhea.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definitions of enterotoxins and endotoxins. Enterotoxins are toxins that specifically target the intestines and are typically secreted by bacteria.
2. Step 2: Recognize that endotoxins are components of the outer membrane of Gram-negative bacteria, specifically lipopolysaccharides (LPS), and are not secreted but released when the bacterial cell is lysed.
3. Step 3: Compare the nature of the two toxins: enterotoxins are proteins actively secreted by bacteria, while endotoxins are structural molecules part of the bacterial cell wall.
4. Step 4: Note the effects of each toxin: enterotoxins often cause symptoms like diarrhea by affecting intestinal cells, whereas endotoxins can trigger systemic responses such as fever and inflammation.
5. Step 5: Use this information to identify the correct description: enterotoxins are secreted proteins targeting intestines, and endotoxins are lipopolysaccharides found in the outer membrane of Gram-negative bacteria.