Toxin << TOK suhn >> is a poison produced by a living organism. Toxins may cause many life-threatening diseases and even death. Some toxins remain inside the organism that produces them. They are called endotoxins. They cause poisoning only when the organism is broken up and the poison escapes. Other toxins, called exotoxins or ectotoxins, are secreted into the substance surrounding the organism.
Bacteria that infect the human body may produce toxins that cause diphtheria, tetanus, and scarlet fever. Some bacteria and fungi secrete toxins into the foods in which they grow. Such serious diseases as botulism and ergotism may result if such food is eaten.
Some tropical fish produce toxins that can cause illness or death to a person who eats the fish. The venoms of poisonous snakes, spiders, and insects are toxins. Doctors use antitoxins to fight toxins (see Antitoxin).
