Escherichia vulneris osteomyelitis of the tibia caused by a wooden foreign body

A new species in the family Enterobacteriaceae, Escherichia vulneris, was characterized by the Centers for Disease Control and Prevention in 1982. It has been shown to have a predilection for human wounds, and several case reports have described superficial wound infections with this rare organism. Until now, however, there have been no reports of osteomyelitis occurring secondary to E vulneris infection. The authors present the case of a 13-year-old boy who fell on a stick and sustained a penetrating injury to his right knee. Radiographs and magnetic resonance imaging revealed a lytic lesion with a foreign body in the tibial epiphysis. On culture, only E vulneris was found, and histologic examination showed the foreign body to be surrounded by acute and chronic inflammation, abscess formation, and foreign-body giant-cell reaction. Although a recent study questioned the pathogenicity of this organism after reviewing the cases of 12 patients in whom there was concurrent heavy growth of Staphylococcus aureus, the present case supports the finding that E vulneris is a human pathogen that should be treated when obtained from human wound cultures.