What are exotoxins?

Exotoxins are toxic substances that are secreted by bacteria into their environment. This definition highlights several key aspects of exotoxins. Firstly, they are produced by living bacteria, making them distinct from other toxic substances that may be released only upon cell lysis. Unlike endotoxins, which are part of the bacterial cell wall and released when a bacterium dies, exotoxins are actively secreted during the growth phase of the bacteria.

Exotoxins can act at a distance from where they are produced and can cause damage to host tissues, interfere with normal cellular functions, and provoke strong immune responses. They can have diverse modes of action and can be classified based on their specific functions, such as neurotoxins, enterotoxins, and cytotoxins, impacting different cellular processes or systems.

This understanding of exotoxins emphasizes their role as virulence factors in pathogenic bacteria and their implications in disease, aiding in the development of vaccines and therapeutic treatments.