Streptococcus equinus septicemia: report of two cases and review of the literature.

Two cases of septicemia with Streptococcus equinus, a group D streptococcus, are reported, and the literature pertaining to infections with this organism is reviewed. Both of our patients presented with obvious signs of infection, had S equinus isolated from multiple blood cultures, and had a good clinical response to penicillin therapy, alone or in combination with streptomycin. In vitro testing of the isolates confirmed susceptibility to penicillin. S equinus should now be recognized as a human pathogen as are the other group D streptococci, S bovis and the enterococci.