Studies in staphylococcal fever. V. Staphlococcal filtrate pyrogen.

Broth culture filtrates from several strains of Staphylococcus aureus produce fever when injected intravenously into normal or previously sensitized rabbits.' This response appears to depend upon a naturally acquired state of delayed hypersensitivity, which may be increased with specific infection.2 Rabbits made unreactive (tolerant) to filtrate from one staphylococcal strain were tolerant to filtrate from two other strains,2 so that a common antigen may be responsible for the pyrogenic activity of different staphylococcal filtrates. Since only actively multiplying staphylococci release pyrogen,1 this agent may be an "exotoxin." Many staphylococcal toxins have been identified, yet few influence the manifestations or pathogenesis of staphylococcal infection.8 Furthermore, although staphylococcal infection in man produces both circulating antibody and a state of delayed hypersensitivity to various staphylococcal antigens, the influence of these host responses on either the development or the symptomatology of staphylococcal disease is not clear.' Since fever is such a prominent manifestation of both infection and hypersensitivity, a staphylococcal product that produces fever by a hypersensitivity reaction might also have other effects on the course of staphylococcal infections. It seemed of interest, therefore, to study further the pyrogen produced in staphylococcal filtrates in an attempt to characterize its chemical nature, its relation to known staphylococcal antigens, and to known filtrable products or toxins of the staphylococcus.