Oral microbiomes of patients with infective endocarditis (IE): a comparative pilot study of IE patients, patients at risk for IE and healthy controls.

BACKGROUND

Infective endocarditis (IE) is an uncommon disease with high morbidity and mortality rates, which often develops from oral bacterial species entering circulation.

OBJECTIVE

We compared oral microbiome profiles of three groups: IE patients (N  9 patients; n = 27 samples), disease controls at risk for IE (N = 28; n = 84), and healthy controls (N = 37; n = 111). Bacterial species in IE patients' blood cultures were identified for comparison with matched oral samples.

DESIGN

Oral microbiome profiles were obtained from buccal mucosa, saliva, and tongue samples for all three groups and from sub- and supra-gingival plaque samples of the IE group (N = 9; n = 16) and disease controls (N = 28; n = 54). - and -diversities were determined based on relative abundance data. Discriminative species were identified by LEfSe, Mann-Whitney, and ROC analyses. Identity of the bacterial species in IE patients' blood cultures was confirmed by gene Sanger sequencing.

RESULTS

• and -diversities differed between groups. Discriminative IE-associated species were identified, and . Two blood isolates were , also identified in one matched saliva sample. was present in one patient's plaque samples and blood culture.

CONCLUSIONS

Oral microbiomes of IE, non-IE disease controls, and healthy controls differed significantly. A better understanding of IE-related bacterial-host interactions is warranted.