title: Evaluation of VITEK mass spectrometry (MS), a matrix-assisted laser desorption ionization time-of-flight MS system for identification of anaerobic bacteria.
abstract: BACKGROUND
  By conventional methods, the identification of anaerobic bacteria is more time consuming and requires more expertise than the identification of aerobic bacteria. Although the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are relatively less studied, they have been reported to be a promising method for the identification of anaerobes. We evaluated the performance of the VITEK MS in vitro diagnostic (IVD; 1.1 database; bioMérieux, France) in the identification of anaerobes.
  
  
  METHODS
  We used 274 anaerobic bacteria isolated from various clinical specimens. The results for the identification of the bacteria by VITEK MS were compared to those obtained by phenotypic methods and 16S rRNA gene sequencing.
  
  
  RESULTS
  Among the 249 isolates included in the IVD database, the VITEK MS correctly identified 209 (83.9%) isolates to the species level and an additional 18 (7.2%) at the genus level. In particular, the VITEK MS correctly identified clinically relevant and frequently isolated anaerobic bacteria to the species level. The remaining 22 isolates (8.8%) were either not identified or misidentified. The VITEK MS could not identify the 25 isolates absent from the IVD database to the species level.
  
  
  CONCLUSIONS
  The VITEK MS showed reliable identifications for clinically relevant anaerobic bacteria.
authors.affiliation: Department of Laboratory Medicine, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Wonmok
authors.initials: W
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Myungsook
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dongeun
authors.initials: D
authors.lastname: Yong
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yunsop
authors.initials: Y
authors.lastname: Chong
mesh_terms: D001421:Bacteria, Anaerobic / Q000235:genetics* / Q000302:isolation & purification; D015373:Bacterial Typing Techniques / Q000295:instrumentation* / Q000379:methods*; D001826:Body Fluids / Q000382:microbiology; D030541:Databases, Genetic; D006801:Humans; D012336:RNA, Ribosomal, 16S / Q000032:analysis* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Anaerobic bacteria; MALDI-TOF MS; VITEK MS