16S rRNA Metabarcoding Used to Identify the Etiology of Infective Endocarditis Agents

<b>The aim of the study</b> was to estimate the efficiency of identifying bacterial agents in native cardiac valves affected by infective endocarditis using 16S rRNA metabarcoding.<h4>Materials and methods</h4>The study material involved 20 native cardiac valve samples from 16 patients. Sequencing was carried out in the Center for Collective Use "Genomics" (Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Russia) on a sequenator MiSeq (Illumina, USA) using MiSeq Reagent Kit v3 (2×300 bp; Illumina, USA).<h4>Results</h4>The study revealed major microorganisms (their portion in the sample under study was over 5% from all identified bacterial agents) belonging to <i>Streptococcus</i> (40% of all valves studied), <i>Sphingomonas</i> (35%), <i>Pseudomonas</i> (35%), <i>Roseateles</i> (25%), <i>Phyllobacterium</i> (25%), and <i>Enterococcus</i> (15%). Moreover, the studied valves were found to have rare cases of <i>Ralstonia pickettii</i>, as well as <i>Bacillus</i> and <i>Klebsiella</i> representatives.<h4>Conclusion</h4>The findings demonstrated the efficiency of 16S rRNA metabarcoding in identifying bacterial agents compared to routine noninvasive diagnostic methods. Native cardiac valves isolated from the patients with infective endocarditis were characterized by numerous opportunistic pathogenic bacteria in negative blood cultures.