Streptococcus gordonii endocarditis

Infective endocarditis is a deadly condition with severe complications. Its diagnosis is determined through clinical, biological, microbiological and imaging criteria. The pathogens implicated in the disease are widely acknowledged, such as Staphylococcus aureus, oral streptococci, coagulase-negative staphylococci, enterococci and the HACEK group. Usage of cell-free bacterial DNA (cfDNA) might improve the diagnosis, e.g. when patients have been previously exposed to antimicrobials. We report a case of subacute aortic valve endocarditis that was attributed to Solobacterium moorei based on plasma mcfDNA analysis. Interestingly, metagenomic next-generation sequencing analysis at the autopsy, performed 10 weeks later, revealed the presence of Streptococcus gordonii, while S. moorei was no longer detected. This suggests that the molecular detection of infective endocarditis can provide variable results, possibly related to the sampling time or the anatomic sites (blood or valve) assessed.