새로운 MALDI-TOF 시스템 ASTA MicroIDSys를 이용한 Candida auris 및 연관 균종의 동정

(Identification of Candida auris and Closely Related Species Using a New Matrix-Assisted
Laser Desorption/Ionization Time-of-Flight Mass Spectrometry, the ASTA MicroIDSys
System)

마태오1*·인용하2*·변승아1·이가영1·최민지1·이승엽3·원은정1,4·최현정1·최현우1·기승정1·김수현1,5·신명근1·신종희1
Taeo Ma, M.D.1*, Yong Ha In, M.S.2*, Seung A Byun, M.S.1, Ga Yeong Lee, B.S.1, Min Ji Choi, Ph.D.1, Seung Yeob Lee, M.D.3,
Eun Jeong Won, M.D.1,4, Hyun-Jung Choi, M.D.1, Hyun Woo Choi, M.D.1, Seung Jung Kee, M.D.1, Soo Hyun Kim, M.D.1,5,Myung Geun Shin, M.D.1, Jong Hee Shin, M.D.1
전남대학교 의과대학 진단검사의학교실1, 노스퀘스트 연구소2, 전북대학교 의과대학 진단검사의학교실3, 전남대학교 의과대학 기생충학교실4,
전남대학교 의과대학 미생물학교실5
Department of Laboratory Medicine1, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun;
Research and Development Center of Nosquest Inc.2, Seongnam; Department of Laboratory Medicine3, Jeonbuk National University Medical
School and Hospital, Jeonju; Department of Parasitology and Tropical Medicine4, Chonnam National University Medical School, Hwasun;
Department of Microbiology5, Chonnam National University Medical School, Hwasun, Korea

 

Abstract

Candida auris is a multidrug-resistant fungal pathogen emerging worldwide that is closely related to the C. haemulonii species complex. The ASTA MicroIDSys (ASTA, Korea) is a new matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system developed for species-level identification of microorganisms. However, prior to the current study, the reference database of ASTA MicroIDSys did not include C. auris. We expanded the database by adding 20 reference strains of C. auris and three closely related species belonging to C. haemulonii species complex. Further, we compared the performance of the ASTA system using an expanded database (coreDB v1.27.02) to that of the Biotyper system (Bruker Daltonics, USA) using 91 well-characterized Candida isolates from a Korean collection. In addition, we evaluated the ability of the ASTA system to differentiate between clade II and non-clade II isolates of C. auris. The results revealed that both ASTA and Biotyper systems accurately identified all 73 C. auris isolates. Of the 18 isolates of closely related species (nine C. pseudohaemulonii, seven C. haemulonii, and two C. haemulonii var. vulnera), the ASTA and Biotyper systems correctly identified 16 and 14 isolates, respectively, to the species level. Neither system misidentified any of the 91 isolates. Cluster analyses of the ASTA spectra distinctly discriminated clade II Korean C. auris isolates from the nonclade II isolates obtained from other countries. Our results show that the ASTA system with an expanded database is a reliable platform for the identification of C. auris and closely related species.