Sternotomy infection with Mycoplasma hominis: a cause of "culture negative" wound infection

Wound infections with Mycoplasma species are unusual; diagnosis may be delayed because of the growth characteristics of this organism. We report Mycoplasma hominis infection of sternotomy wounds in two patients. The first presented with fever and drainage from the incision 1 week after coronary artery bypass grafting. The other patient presented with drainage from the incision three weeks after double-lung transplantation. In both cases, initial cultures were negative, but the typical colonial morphology of M. hominis was subsequently detected. Successful treatment consisted of debridement and long courses of antibiotic therapy; omental flap grafting was eventually required for the second patient. Other published cases were reviewed and compared with the newly reported cases.