Evaluation of the MALDI-TOF MS in-house database in identification of clinical filamentous fungi isolates

Abstract

Abstract: Objective To evaluate the MALDI-TOF MS in-house database in identification of clinical filamentous fungi isolates. Methods Forty-one filamentous fungi isolates genetically confirmed by molecular sequencing method were used as the representative strains to construct the MALDI-TOF MS in-house database. The mass spectra profiles of the representative strains from young stage and mature stage colonies were created respectively according to the standard extraction procedure into the in-house database. The MALDI-TOF MS in-house database was challenged subsequently to identify other 236 clinical filamentous fungi isolates. Results The MALDI-TOF MS in-house database included 82 mass spectra profiles of 41 representative strains from 10 genera and 25 species. The species level identification rate of the 236 evaluated isolates could be increased from 29.2% (69/236) with the Bruker commercial library to 67.5% (159/236) with the MALDI-TOF MS in-house database; the highest species level identification rate was 76.3% (180/236) after combining the Bruker commercial library with the in-house database. There was no advantage of the MALDI-TOF MS in-house database in identification of common Aspergillus isolates than the morphological method. While for the cryptic species of Aspergillus and non-Aspergillus filemantous fungi, the species level identification rate was 61.8% (34/55) by the MALDI-TOF MS in-house database which significantly superior than the morphological method rate of 16.4% (9/55). Conclusions The in-house database could improve the performance of MALDI-TOF MS in identification of filamentous fungi isolates, especially for the less encountered species which were difficult to be identified with the conventional morphological method.

Key words: MALDI-TOF MS, filamentous fungi, in-house database, identification

CLC Number:

R446.5
R379

LI Ying, HUANG Jingjing, LIU Wenjing, WANG Peichang, XU Yingchun. Evaluation of the MALDI-TOF MS in-house database in identification of clinical filamentous fungi isolates[J]. Chinese Journal of Mycology, 2021, 16(6): 361-366.

References

[1] TACCONE F S, VAN DEN ABEELE A M, BULPA P, et al. Epidemiology of invasive aspergillosis in critically ill patients: clinical presentation, underlying conditions, and outcomes[J]. Crit Care, 2015, 19(1): 7.
[2] CHEN M, XU Y, HONG N, et al. Epidemiology of fungal infections in China [J]. Front Med, 2018, 12(1): 58-75.
[3] 徐媛, 陈敏, 廖万清. 中国侵袭性曲霉菌病流行病学现状[J]. 中国真菌学杂志, 2018, 13(1): 57-60.
[4] POSCH W, BLATZER M, WILFLINGSEDER D, et al. Aspergillus terreus: novel lessons learned on amphotericin B resistance [J]. Med Mycol, 2018, 56(suppl 1): 73-82.
[5] Al-HATMI A M, MEIS J F, DE HOOG G S. Fusarium: molecular diversity and intrinsic drug resistance [J]. PLoS Pathog, 2016, 12(4):e1005464.
[6] DANNAOUI E. Antifungal resistance in Mucorales [J]. Int J Antimicrob Agents, 2017, 50(5): 617-621.
[7] LI Y, WANG H, ZHAO Y P, et al. Evaluation of the Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identification of Aspergillus species directly from growth on solid agar media [J]. Front Microbiol, 2017, 8:1209.
[8] Stein M, TRAN V, NICHOL K A, et al. Evaluation of three MALDI-TOF mass spectrometry libraries for the identification of filamentous fungi in three clinical microbiology laboratories in Manitoba, Canada [J]. Mycoses, 2018, 61(10):743-753.
[9] LAU A F, DRAKE S K, CALHOUN L B, et al. Development of a clinically comprehensive databaseand a simple procedure for identification of molds from solid media by matrix-assisted laser desorption ionization-time of flight mass spectrometry [J]. J Clin Microbiol, 2013, 51(3): 828-834.
[10] LAU A F, WALCHAK R C, MILLER H B, et al. Multicenter study demonstrates standardization requirements for mold identification by MALDI-TOF MS [J]. Front Microbiol, 2019, 10: 2098.
[11] NORMAND A C, BECKER P, GABRIEL F, et al. Validation of a new web application for identification of fungi by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry [J]. J Clin Microbiol, 2017, 55(9): 2661-2670.
[12] IMBERT S, NORMAND A C, GABRIEL F, et al. Multi-centric evaluation of the online MSI platform for the identification of cryptic and rare species of Aspergillus by MALDI-TOF [J]. Med Mycol, 2019, 57(8): 962-968.
[13] 罗燕萍, 徐英春, 王辉, 等. 自建MALDI-TOF MS微生物鉴定数据库专家共识[J]. 中华检验医学杂志, 2019, 42(6): 414-419.
[14] 李颖, 徐英春. 评价ITS、BenA和CaM序列分析在曲霉菌种鉴定方面的应用[J]. 中国真菌学杂志, 2017, 12(2): 74-77.
[15] WANG H, XIAO M, KONG F, et al. Accurate and practical identification of 20Fusarium species by seven-locus sequence analysis and reverse line blot hybridization, and an in vitro antifungal susceptibility study[J]. J Clin Microbiol, 2011, 49(5): 1890-1898.
[16] SCHULTHESS B, LEDERMANN R, MOUTTET F, et al. Use of the Bruker MALDI Biotyper for identification of molds in the clinical mycology laboratory[J]. J Clin Microbiol, 2014, 52(8): 2797-2803.
[17] 张桂, 王丽赟, 王玫, 等. MALDI-TOF MS直接涂板法快速鉴定丝状真菌的临床应用[J]. 疾病监测, 2019, 34(11): 980-986.
[18] 李颖, 张戈, 杨洋, 等. 基质辅助激光解吸电离飞行时间质谱鉴定丝状真菌的影响因素分析[J]. 协和医学杂志, 2020, 11(2): 156-161.
[19] SLEIMAN S, HALLIDAY C L, CHAPMAN B, et al. Performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of Aspergillus, Scedosporium, and Fusarium spp. in the Australian clinical setting [J]. J Clin Microbiol, 2016, 54(8): 2182-2186.