title: Multicenter study evaluating the Vitek MS system for identification of medically important yeasts.
abstract: The optimal management of fungal infections is correlated with timely organism identification. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is revolutionizing the identification of yeasts isolated from clinical specimens. We present a multicenter study assessing the performance of the Vitek MS system (bioMérieux) in identifying medically important yeasts. A collection of 852 isolates was tested, including 20 Candida species (626 isolates, including 58 C. albicans, 62 C. glabrata, and 53 C. krusei isolates), 35 Cryptococcus neoformans isolates, and 191 other clinically relevant yeast isolates; in total, 31 different species were evaluated. Isolates were directly applied to a target plate, followed by a formic acid overlay. Mass spectra were acquired using the Vitek MS system and were analyzed using the Vitek MS v2.0 database. The gold standard for identification was sequence analysis of the D2 region of the 26S rRNA gene. In total, 823 isolates (96.6%) were identified to the genus level and 819 isolates (96.1%) were identified to the species level. Twenty-four isolates (2.8%) were not identified, and five isolates (0.6%) were misidentified. Misidentified isolates included one isolate of C. albicans (n = 58) identified as Candida dubliniensis, one isolate of Candida parapsilosis (n = 73) identified as Candida pelliculosa, and three isolates of Geotrichum klebahnii (n = 6) identified as Geotrichum candidum. The identification of clinically relevant yeasts using MS is superior to the phenotypic identification systems currently employed in clinical microbiology laboratories.
authors: Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors: Lars F
authors: LF
authors: Westblade
authors: Rebecca
authors: R
authors: Jennemann
authors: John A
authors: JA
authors: Branda
authors: Maureen
authors: M
authors: Bythrow
authors: Mary Jane
authors: MJ
authors: Ferraro
authors: Omai B
authors: OB
authors: Garner
authors: Christine C
authors: CC
authors: Ginocchio
authors: Michael A
authors: MA
authors: Lewinski
authors: Ryhana
authors: R
authors: Manji
authors: A Brian
authors: AB
authors: Mochon
authors: Gary W
authors: GW
authors: Procop
authors: Sandra S
authors: SS
authors: Richter
authors: Jenna A
authors: JA
authors: Rychert
authors: Linda
authors: L
authors: Sercia
authors: Carey-Ann D
authors: CA
authors: Burnham
mesh_terms: D019411:Clinical Laboratory Techniques / Q000379:methods*; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D006801:Humans; D009172:Mycology / Q000379:methods*; D009181:Mycoses / Q000175:diagnosis* / Q000382:microbiology*; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D015003:Yeasts / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification*
references: Future Microbiol. 2012 May;7(5):639-55
references: 22568718
references: Clin Microbiol Infect. 2011 Sep;17(9):1359-65
references: 20946411
references: Diagn Microbiol Infect Dis. 2012 May;73(1):65-7
references: 22578939
references: Mass Spectrom Rev. 2001 Jul-Aug;20(4):157-71
references: 11835304
references: Exp Dermatol. 2008 Apr;17(4):356-61
references: 17979969
references: Antimicrob Agents Chemother. 1997 Mar;41(3):617-23
references: 9056003
references: Clin Microbiol Infect. 2004 Mar;10 Suppl 1:48-66
references: 14748802
references: Microbes Infect. 2011 Oct;13(11):895-907
references: 21684347
references: J Clin Microbiol. 2012 Sep;50(9):3066-8
references: 22718939
references: Ann Pharmacother. 2012 Jul-Aug;46(7-8):1086-96
references: 22811350
references: J Clin Microbiol. 2007 Apr;45(4):1343-6
references: 17287333
references: J Clin Microbiol. 2007 Apr;45(4):1087-92
references: 17267631
references: Clin Infect Dis. 2009 Mar 1;48(5):503-35
references: 19191635
references: Med Mycol. 2013 May;51(4):371-7
references: 22978312
references: J Clin Microbiol. 2009 Sep;47(9):2912-7
references: 19571014
references: Crit Care. 2011;15(6):R287
references: 22126425
references: Med Mycol. 2001 Feb;39(1):9-33
references: 11270413
references: Clin Infect Dis. 2006 Jul 1;43(1):25-31
references: 16758414
references: J Clin Microbiol. 2003 Nov;41(11):5099-102
references: 14605145
references: J Clin Microbiol. 2012 Jul;50(7):2472-6
references: 22573595
references: Clin Microbiol Infect. 2009 Jul;15(7):634-42
references: 19456834
references: Clin Infect Dis. 2012 Apr;54(8):1110-22
references: 22412055
references: JAMA. 2010 Apr 28;303(16):1617-24
references: 20424252
references: J Clin Microbiol. 2011 Apr;49(4):1614-6
references: 21270234
references: J Clin Microbiol. 2012 Sep;50(9):3093-5
references: 22760034
references: Eur J Clin Microbiol Infect Dis. 2001 May;20(5):366-7
references: 11453605
references: Clin Microbiol Infect. 2009 Jul;15(7):613-24
references: 19673972
references: J Clin Pathol. 1999 Apr;52(4):271-3
references: 10474518
references: Med Mycol. 2007 Mar;45(2):97-121
references: 17365647
references: Methods Mol Biol. 2013;968:25-54
references: 23296883
references: J Clin Microbiol. 2010 Oct;48(10):3482-6
references: 20668126
references: J Clin Microbiol. 2012 Oct;50(10):3301-8
references: 22855510
references: J Clin Microbiol. 2012 Jun;50(6):2107-10
references: 22495559
references: Curr Infect Dis Rep. 2012 Dec;14(6):668-75
references: 23065419
references: Semin Respir Crit Care Med. 2011 Apr;32(2):159-73
references: 21506052