Native aortic endocarditis due to an unusual pathogen: Actinotignum schaalii.

We report a case of aortic native valve endocarditis due to Actinotignum schaalii in an 89-year-old man with prostatism history but no signs of urinary infection. Actinotignum schaalii was isolated not only from positive blood culture but also from cardiac valve culture using mass spectrometry and 16S rDNA sequencing. Actinotignum schaalii is recognized as commensal of genitourinary tract, but it was underdiagnosed. The advances in bacterial identification such as MALDI-TOF MS probably explain the increasing described cases of infections due to A. schaalii these last years.