TOXIC-SHOCK-SYNDROME TOXIN-1 CONTRIBUTES TO THE ARTHRITOGENICITY OF STAPHYLOCOCCUS-AUREUS

Although enterotoxins have been implicated in disease states such as f ood poisoning and toxic shock syndrome, their role in infectious arthr itis is not known. To study the arthritogenic properties of toxic shoc k syndrome toxin 1 (TSST-1), two pairs of S. aureus strains isogenic f or TSST-1 production were injected intravenously into healthy Swiss mi ce. Mice injected with TSST-1-secreting staphylococcal strains develop ed more frequent and more severe arthritis than did mice inoculated wi th the isogenic TSST-1-deficient counterparts. Immunohistochemical ana lysis of arthritic joints revealed an equal number of infiltrating pha gocytes in both groups; however, mice inoculated with TSST-1-producing staphylococci had significantly more (P < .01) interleukin-2 receptor -expressing cells in the inflamed synovium than did mice that received the isogenic counterpart. Thus, TSST-1 is a virulence determinant in S. aureus arthritis in mice. The precise mechanism by which this toxin contributes to the development and progression of arthritis needs fur ther investigation.