The oral microbiota in patients undergoing coronary artery bypass graft surgery

The oral cavity houses a diverse community of microorganisms which play an important role in maintaining the health of the individual. The coexistence of periodontal infections with coronary artery disease (CAD) has been shown in many studies. We investigated the presence and abundance of periodontitis-causing bacteria in patients with CAD. The oral microbiome of five patients admitted for coronary artery bypass graft (CABG) surgery was analysed by metagenomic sequencing of 16 s ribosomal ribonucleic acid (rRNA) gene amplicons. Two samples of oral mouthwash were collected 48-72 h apart when the patients were in the intensive care unit. Abundance and diversity of oral bacterial flora were analysed. The most abundant phyla were Firmicutes and Bacteroidetes. Less than 5% of the taxa in this group of patients belonged to the phylum Proteobacteria. Though there were variations in the abundance of the bacterial species in the immediate postoperative period, there was no major change in the overall diversity. High counts of periodontal pathogens such as Tannerella forsythia, Campylobacter rectus, Fusobacterium nucleatum, Prevotella intermedia, and Treponema denticola were seen in most of the patients.