Case report: We present a case of a 66-year-old female diagnosed with R. gnavus bacteremia associated with fecal peritonits secondary to small-bowel herniation and perforation. Identification as R. gnavus was delayed because of absence of this species in the MALDI-TOF MS database (Vitek MS, bioMérieux). Identification was provided by 16S rRNA gene sequencing. Review: R. gnavus, a Gram-positive, strictly anaerobic bacterium, is a member of the human gut microbiota. Dysbiosis in the gut microbiota, with increased amounts of R. gnavus, has been described in inflammatory bowel disease. R. gnavus has only been reported occasionally as the cause of infections. Hence the potential pathogenicity is not yet fully recognized, and data regarding the antimicrobial susceptibility profile are rare. Identification of anaerobic bacteria such as R. gnavus is greatly accelerated as a result of the introduction of MALDI-TOF MS. However, as illustrated in this case report, an extensive and up-to-date MALDI-TOF MS database is necessary for providing an accurate identification.
Keywords: MALDI-TOF MS; bacteremia.