Ruminococcus gnavus total hip arthroplasty infection in a 62-year-old man with ulcerative colitis.

We report the case of a total hip arthroplasty infection caused by Ruminococcus gnavus in a 62-year-old man with ulcerative colitis. The bacterium was perfectly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry.