title: Differentiation of vanA-positive Enterococcus faecium from vanA-negative E. faecium by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry.
abstract: Vancomycin-resistant enterococci are important nosocomial pathogens that require rapid and accurate detection for infection control. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) has begun to be used in many clinical laboratories because it is a rapid, simple and inexpensive method for identifying micro-organisms. In this study, the performance of MALDI-TOF/MS to differentiate vanA-positive Enterococcus faecium (VPEF) from vanA-negative E. faecium (VNEF) was evaluated. A total of 61 VPEF isolates collected during regional surveillance in Kyoto (Japan) and 71 VNEF isolates collected from bacteraemia patients were analysed using MALDI-TOF/MS with three ClinProTools models. All of the isolates were correctly identified as E. faecium using the MALDI Biotyper system. To discriminate between VPEF and VNEF, all three ClinProTools models yielded >90% recognition capability (basic sensitivity) and cross-validation (reliability of the models); the genetic algorithm model exhibited the highest performance (99.18% and 92.40%, respectively). The high detection performance of MALDI-TOF/MS for VPEF offers the potential for routine laboratory use.
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakano
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: yazblood@kuhp.kyoto-u.ac.jp.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Matsumura
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Karin
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yunoki
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Hotta
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Noguchi
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Nagao
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Takakura
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ichiyama
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001431:Bacteriological Techniques / Q000379:methods*; D019729:Carbon-Oxygen Ligases / Q000378:metabolism*; D016984:Enterococcus faecium / Q000145:classification* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D007564:Japan; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D065507:Vancomycin-Resistant Enterococci / Q000145:classification* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D019729:Carbon-Oxygen Ligases
keywords: ClinProTools; MALDI-TOF/MS; VRE; vanA-positive Enterococcus faecium