title: Identification of UncommonCandidaSpecies Using Commercial Identification Systems.
abstract: Recently, several studies have revealed that commercial microbial identification systems do not accurately identify the uncommon causative species of candidiasis, includingCandida famata,Meyerozyma guilliermondii, andC. auris. We investigated the accuracy of species-level identification in a collection of clinical isolates previously identified asC. famata(N= 38),C. lusitaniae(N= 1 2), andM. guilliermondii(N= 5) by the Vitek 2 system. All 55 isolates were re-analyzed by the Phoenix system (Becton Dickinson Diagnostics), two matrix-assisted laser desorption ionization-time of flight mass spectrometry analyzers (a Vitek MS and a Bruker Biotyper), and by sequencing of internal transcribed spacer (ITS) regions or 26S rRNA gene D1/D2 domains. Among 38 isolates previously identified asC. famataby the Vitek 2 system, the majority (27/38 isolates, 71.1%) were identified asC. tropicalis(20 isolates) or C. albicans (7 isolates) by ITS sequencing, and none was identified asC. famata. Among 20 isolates that were identified asC. tropicalis, 17 (85%) were isolated from urine. The two isolates that were identified asC. aurisby ITS sequencing originated from ear discharge. The Phoenix system did not accurately identifyC. lusitaniae,C. krusei, orC. auris. The correct identification rate for 55 isolates was 92.7% (51/55 isolates) for the Vitek MS and 94.6% (52/55 isolates) for the Bruker Biotyper, as compared with results from ITS sequencing. These results suggest thatC. famatais very rare in Korea, and that the possibility of misidentification should be noted when an uncommonCandidaspecies is identified.
authors.affiliation: Department of Urology, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea.
authors.forename: Tae-Hyoung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea.
authors.forename: Oh Joo
authors.initials: OJ
authors.lastname: Kweon
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea.
authors.forename: Hye Ryoun
authors.initials: HR
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Lee
mesh_terms: D001769:Blood / Q000382:microbiology; D002175:Candida / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D002177:Candidiasis / Q000175:diagnosis / Q000382:microbiology*; D004423:Ear / Q000382:microbiology; D006801:Humans; D013058:Mass Spectrometry / Q000191:economics / Q000379:methods*; D011933:Reagent Kits, Diagnostic / Q000191:economics; D017422:Sequence Analysis, DNA / Q000191:economics / Q000379:methods*; D013183:Sputum / Q000382:microbiology; D014556:Urine / Q000382:microbiology
chemical_list: D011933:Reagent Kits, Diagnostic
keywords: Candida; MALDI-TOF MS; identification; sequencing