Detoxification of staphylococcal alpha toxin by hydrocortisone and methylprednisolone.

The effects of hydrocortisone (HC) and methylprednisolone (MP) on the biological activities of staphylococcol alpha toxin were studied. Incubation of either HC or MP at concentrations of 4-8 mg per ml with purified alpha toxin (690 HU per ml) reduced or eliminated haemolytic activity for rabbit red cells, intraperitoneal lethality for mice, and dermonecrotic activity for rabbits. Detoxification was related to the dose of steroid, and MP was slightly more active than HC. The mechanism of detoxification apparently involves a direct molecular interaction between alpha toxin and steroid, and pretreatment of animals with HC or MP did not enhance their resistance to the subsequent effect of toxin.