title: MALDI-TOF MS versus VITEK 2 ANC card for identification of anaerobic bacteria.
abstract: BACKGROUND
  Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an accurate, rapid and inexpensive technique that has initiated a revolution in the clinical microbiology laboratory for identification of pathogens. The Vitek 2 anaerobe and Corynebacterium (ANC) identification card is a newly developed method for identification of corynebacteria and anaerobic species. The aim of this study was to evaluate the effectiveness of the ANC card and MALDI-TOF MS techniques for identification of clinical anaerobic isolates.
  
  
  METHODS
  Five reference strains and a total of 50 anaerobic bacteria clinical isolates comprising ten different genera and 14 species were identified and analyzed by the ANC card together with Vitek 2 identification system and Vitek MS together with version 2.0 database respectively. 16S rRNA gene sequencing was used as reference method for accuracy in the identification.
  
  
  RESULTS
  Vitek 2 ANC card and Vitek MS provided comparable results at species level for the five reference strains. Of 50 clinical strains, the Vitek MS provided identification for 46 strains (92%) to the species level, 47 (94%) to genus level, one (2%) low discrimination, two (4%) no identification and one (2%) misidentification. The Vitek 2 ANC card provided identification for 43 strains (86%) correct to the species level, 47 (94%) correct to the genus level, three (6%) low discrimination, three (6%) no identification and one (2%) misidentification.
  
  
  CONCLUSIONS
  Both Vitek MS and Vitek 2 ANC card can be used for accurate routine clinical anaerobe identification. Comparing to the Vitek 2 ANC card, Vitek MS is easier, faster and more economic for each test. The databases currently available for both systems should be updated and further developed to enhance performance.
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Gu
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Genyan
authors.initials: G
authors.lastname: Liu
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Xia
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Fan
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Yaning
authors.initials: Y
authors.lastname: Mei
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Peijun
authors.initials: P
authors.lastname: Huang
authors.affiliation: 1 Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China ; 2 National Key Clinical Department of Laboratory Medicine, Nanjing 210029, China.
authors.forename: Shiyang
authors.initials: S
authors.lastname: Pan
keywords: Anaerobe; Vitek 2 anaerobe and Corynebacterium card (Vitek 2 ANC card); identification; matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)