Streptococcal pyrogenic toxins

Definition

Streptococcal pyrogenic toxins are exotoxins produced by certain strains of Streptococcus pyogenes. These toxins are known for their role in causing severe immune responses and diseases such as scarlet fever and toxic shock syndrome.

5 Must Know Facts For Your Next Test

1. Streptococcal pyrogenic toxins function as superantigens, leading to an excessive activation of T cells.
2. There are three main types: SpeA, SpeB, and SpeC, with SpeA being the most studied due to its high virulence.
3. These toxins can cause a cytokine storm, resulting in severe inflammation and tissue damage.
4. They play a critical role in the pathogenesis of diseases like necrotizing fasciitis and streptococcal toxic shock syndrome.
5. The genes encoding these toxins are often carried on bacteriophages integrated into the bacterial genome.

Review Questions

• What is the primary mechanism by which streptococcal pyrogenic toxins cause harm to the host?
• Name at least two diseases associated with streptococcal pyrogenic toxins.
• How do streptococcal pyrogenic toxins contribute to a cytokine storm?

Related terms

Superantigen: A class of antigens that result in excessive activation of the immune system by binding directly to MHC molecules and T-cell receptors.

Cytokine Storm: An overproduction of immune cells and their activating compounds (cytokines), often leading to severe inflammation and tissue damage.

Necrotizing Fasciitis: A severe bacterial infection causing rapid tissue death, commonly associated with Streptococcus pyogenes.