Experimental models of bacterial arthritis: a microbiologic and histopathologic characterization of the arthritis after the intraarticular injections of Neisseria gonorrhoeae, Staphylococcus aureus, group A streptococci, and Escherichia coli.

We report the first reproducible experimental model of gonococcal arthritis, utilizing the intraarticular injection of virulent strains of N. gonorrhoeae. An acute, purulent synovitis with a marked polymorphonuclear leukocyte infiltrate developed during the 1st 24 h and persisted for at least 72 h, followed by a more chronic, mononuclear, proliferative synovitis. The histopathologic characteristics of this acute, then chronic synovitis were comparable to that after the intraarticular injection of other bacteria. N. gonorrhoeae could not be recovered from the injected joints 24 h after their inoculation, whereas Staphylococcus aureus, hemolytic streptococci, and E. coli could be recovered for days to weeks after the intraarticular injection.