Ruminococcus gnavus bacteremia associated with fecal peritonitis secondary to small bowel perforation

Ruminococcus gnavus is a common and abundant member of the human gut microbiota. Infections due to R. gnavus have been reported only rarely. In this letter, we illustrate the importance of a comprehensive and up-to-date database for rapid and accurate identification of anaerobic bacteria by matrix-assisted laser desorption ionization-time of flight mass spectrometry. We report a case of bacteremia with R. gnavus associated with fecal peritonitis secondary to a small bowel strangulated hernia and perforation (Fig. 1a,b). Surgical resection of a gangrenous small bowel segment and abdominal lavage was performed. Anaerobic blood cultures on day +5 revealed catalase negative Gram-positive diplococcic. Species identification was performed using partial 16S rRNA gene sequencing (MicroSeq 500 kit, Life Technologies, Foster City, CA) and MALDI BioTyper (software version 3.1; library version 4.0.0.1) MALDI-TOF MS system (Bruker Daltonics, Germany). Species identification of the isolate as R. gnavus was confirmed. Patient was treated with antibiotics and discharged 12 weeks after admittance.