What are exotoxins?

Exotoxins are toxic substances that are actively secreted by bacteria into their surrounding environment. These proteins can be released during bacterial growth and can have various effects on host cells, leading to damage or disruption of normal biological functions. Exotoxins are often specifically identified by their target tissues and the specific diseases they cause. They can act in several ways, including disrupting cellular processes, inhibiting protein synthesis, or damaging cellular membranes.

This definition aligns perfectly with the correct answer, which highlights the significance of exotoxins as actively secreted substances responsible for pathogenesis. Understanding exotoxins is crucial for grasping how certain bacterial infections can lead to severe clinical outcomes.