First description of abdominal infection due to Alistipes onderdonkii.

Alistipes spp is a genus of Gram-negative anaerobic rods involved in very few human diseases. We report the first case of abdominal infection due to Alistipes onderdonkii in a 58-year-old man with a history of chronic obstructive pulmonary disease. He presented with abdominal pain and general malaise after retrogastric drainage for a pancreatitis episode a few days earlier. After the diagnosis of diffuse peritonitis with perforation and necrotizing pancreatic collection, abundant pancreatic fluid was drained and yielded the isolation of A. onderdonkii in pure culture. Resistance to penicillin and moxifloxacin was documented for this strain. Treatment with metronidazole was prescribed, and the patient was discharged after improvement of his general condition.