Formalin-fixed Staphylococcus aureus particles prevent allergic sensitization in a murine model of type I allergy.

Background: Bacterial infections are supposed to act counterregulatory to the development of allergen-specific Th2 immune responses. We analyzed whether administration of extracellular Staphylococcus aureus inhibited experimental sensitization against allergens.

Methods: BALB/c mice were immunized with alum-adsorbed ovalbumin (OVA) together with formalin-fixed Staphylococcus particles.