Exfoliatin

Exfoliatin is a toxin produced by certain strains of the bacterium Staphylococcus aureus. It is a serine protease that specifically cleaves desmoglein 1, a protein involved in cell adhesion in the upper layers of the skin. This cleavage causes the cells to separate from each other, leading to the characteristic skin peeling seen in Staphylococcal scalded skin syndrome (SSSS).

Structure and Function

Exfoliatin is a single-chain protein with a molecular weight of approximately 30,000 Da. It is composed of two domains: a catalytic domain that contains the serine protease active site, and a binding domain that recognizes and binds to desmoglein 1. The toxin is secreted by S. aureus as a zymogen, which is then activated by host proteases.

Pathogenesis

The production of exfoliatin by S. aureus is a major factor in the pathogenesis of SSSS. The toxin is produced locally in the skin, where it cleaves desmoglein 1 and causes the cells in the upper layers of the skin to separate from each other. This leads to the formation of large, fluid-filled blisters that easily rupture, leaving the underlying skin exposed and susceptible to secondary infection.

Treatment and Prevention

Treatment of SSSS involves the administration of antibiotics to eliminate the S. aureus infection, as well as supportive care to manage the skin lesions. Prevention of SSSS is primarily through good hygiene practices to prevent S. aureus colonization and infection.

See Also

• Staphylococcus aureus
• Staphylococcal scalded skin syndrome
• Desmoglein 1
• Serine protease
• Toxin