A toxin formed in fish due to bacteria acting on a chemical in fish is which toxin?

A toxin formed in fish due to bacteria acting on a chemical in fish is which toxin?

• A. Saxitoxin
• B. Scombrotoxin
• C. Shellfish Toxins
• D. Salmonella Typhi

Answer: (B)

This question focuses on toxins produced inside fish when bacteria act on components within the fish to create a toxin, specifically histamine. When certain fish spoil or are not kept cold, bacteria with histidine decarboxylase convert histidine, an amino acid in the fish, into histamine. This histamine-rich toxin is known as scombrotoxin and causes histamine fish poisoning; it is heat-stable, so cooking won’t destroy it, making proper refrigeration and handling essential. The other options don’t fit because saxitoxin is a neurotoxin from algal sources that accumulates in shellfish, shellfish toxins is a broad category linked to shellfish rather than fish forming a toxin in this manner, and Salmonella Typhi is a bacterium causing illness, not a toxin formed in fish.

This question focuses on toxins produced inside fish when bacteria act on components within the fish to create a toxin, specifically histamine. When certain fish spoil or are not kept cold, bacteria with histidine decarboxylase convert histidine, an amino acid in the fish, into histamine. This histamine-rich toxin is known as scombrotoxin and causes histamine fish poisoning; it is heat-stable, so cooking won’t destroy it, making proper refrigeration and handling essential. The other options don’t fit because saxitoxin is a neurotoxin from algal sources that accumulates in shellfish, shellfish toxins is a broad category linked to shellfish rather than fish forming a toxin in this manner, and Salmonella Typhi is a bacterium causing illness, not a toxin formed in fish.