Second case of infective endocarditis caused by Gemella sanguinis

A 69-year-old man presented with a history of spiking fevers and symptoms of transient expressive aphasia and a left hemispheric cerebrovascular accident. A transthoracic echocardiogram revealed thickened mitral leaflets. A subsequent transesophageal echocardiogram demonstrated vegetations on both mitral leaflets and severe mitral regurgitation by color flow imaging. A gram-positive coccus was isolated from the blood culture of this patient.

The bacterium was identified by polymerase chain reaction (PCR) amplification of its 16S rRNA gene with the broad range eubacterial primers, FD1 and RD1, followed by sequencing of the PCR product. The obtained sequence was compared to all sequences deposited in GenBank and the ribosomal database project II. A phylogenetic tree was created to determine the relatedness of this bacterium to other bacterial species.

The phylogenetic tree created from the 1389 bp 16S rDNA sequence indicated that the endocarditis was due to Gemella sanguinis, a member of the normal oral flora and a rare cause of bacteremia.

This report describes the second case of endocarditis caused by G. sanguinis. A history of periodontal disease and tooth abscess in this patient suggests that the oropharynx was the probable origin of the Gemella bacteremia. We propose that G. sanguinis should be added to the list of Gemella species that can cause endocarditis.