title: 16S rRNA sequencing as a diagnostic tool in the identification of culture-negative endocarditis in surgically treated patients.
abstract: OBJECTIVE
  Infective endocarditis (IE) is a worldwide problem, and at least one-third of cases are culture-negative despite the use of appropriate laboratory techniques.
  
  
  METHODS
  A broad-range polymerase chain reaction (PCR) amplification was performed of the 16S rRNA gene, followed by single-strand sequencing for 26 surgically removed heart valves from patients with culture-negative endocarditis who had undergone valve repair or replacement.
  
  
  RESULTS
  Two of the 26 patients were PCR-positive, and sequencing of the amplicon identified the etiological agent. Gram-stained smears of the heart valves were positive in both cases. Three of the remaining 24 cases which were negative by PCR also showed the presence of micro-organisms in Gram-stained smears.
  
  
  CONCLUSIONS
  The study results emphasize that, in suspected IE cases when there is no growth in culture, a combination of microscopy and 16S rRNA sequencing can be used to identify the pathogen in excised valvular tissue.
authors.affiliation: Department of Microbiology, University of Madras, Dr. ALMudaliar Postgraduate Institute of Basic Medical Sciences, Taramani, Chennai, India.
authors.forename: Naveen V
authors.initials: NV
authors.lastname: Kumar
authors.affiliation: Department of Microbiology, University of Madras, Dr. ALMudaliar Postgraduate Institute of Basic Medical Sciences, Taramani, Chennai, India.
authors.forename: Thangam
authors.initials: T
authors.lastname: Menon
authors.affiliation: Department of Microbiology, Frontier Lifeline Hospital, Mogappair, Chennai, India.
authors.forename: Padmaja
authors.initials: P
authors.lastname: Pathipati
authors.affiliation: Department of Cardio Thoracic Surgery, Frontier Lifeline Hospital, Mogappair, Chennai, India.
authors.forename: Kotturathu Mammen
authors.initials: KM
authors.lastname: Cherian
mesh_terms: D000328:Adult; D000368:Aged; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis*; D004697:Endocarditis, Bacterial / Q000175:diagnosis* / Q000382:microbiology / Q000601:surgery; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006351:Heart Valves / Q000382:microbiology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D015203:Reproducibility of Results; D021521:Ribotyping / Q000379:methods*; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S