Abstract 20249: Staphylococci Endocarditis: Metagenomics and Ultrastructural Analysis in Surgically Treated Patients
Introduction: Staphylococci are the most common cause for surgically treated infective endocarditis. No long-term cohort studies of infected endocarditis in cardiac surgery are known yet. Therefore we investigate the occurrence of staphylococci within this population and its phylogenetic species. Because of surgical valve removement, we were able to investigate pathophysiologic condition of involved valves by metagenomic analysis and 3D-electron microscopy.
Hypothesis: Metagenome analysis revealed more sensitive analysis of Staphylococci related species than standard microbiology methods.
Methods: All patient undergoing surgery at our hospital due to infected endocarditis from 2000-2013 were investigated. Scanning electron microscopy (SEM) of infected material was conducted. Furthermore focused ion beam SEM was used to create 3D image-stacks. In four cases bacterial (16S) rRNA was extracted. Metagenomic analysis by next generation sequencing was conducted, using V1-3 and V3-5 primer pairs.
Results: In a 13-years prospective follow-up cohort study, 1647 patients (1165 male, 482 female) underwent cardiac surgical valve replacement following native or prosthesis infective endocarditis. Out of those, 562 cases were tested staphylococci positive by blood culture and/or valve tissue analysis. We identified 12 distinct staphylococci species following phylogenetic classification. Staphylococcus aureus was the most common pathogen in this cohort. Metagenomic analysis of 4 patiens revealed genomic species such as staphylococcus simiae and pasteuri within the same patients and SEM showed intramural and intracellular location of those staphylococci.
Conclusions: Staphylococci species were the most prominent bacteria in infective endocarditis of patients undergoing surgery in our 13 years prospective cohort. One reason for the failure of antibiotic therapy might be intramural and intracellular location of those species. Furthermore phylogenetic analysis revealed several staphylococci species that were not detected by standard molecular microbiologic analysis. We here provide evidence for the notion that extended multidisciplinar analysis of pathogens is needed for calculated antibiosis of infective endocarditis.
Author Disclosures: A. Oberbach: None. S. Feder: None. J. Neuhaus: None. N. Schlichting: None. S. Lehmann: None. S. Lehmann: None. F. Bakthiary: None. M. Lühr: None. F. Mohr: None. Y. Kullnick: None.
- © 2014 by American Heart Association, Inc.