基质辅助激光解析电离飞行时间质谱Clin-TOF-Ⅱ系统对酵母菌鉴定效能评估

Assessment on the identification performance of MALDI-TOF MS Clin-TOF-Ⅱ system for yeast

目的:评估国产Clin-TOF基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)系统对于临床酵母菌的鉴定效能。方法:纳入酵母菌25个菌种,总计156株菌株,均选自中国侵袭性真菌监测网。所有入组菌株均通过内转录间隔区(ITS)扩增测序,准确鉴定至种水平;采用Clin-TOF质谱系统对入组菌株进行直接涂抹法鉴定。结果:Clin-TOF质谱系统对酵母菌准确鉴定率达到95.5%(149/156);其中念珠菌属鉴定准确率为96.8%(122/126);有11株新型隐球菌中有1株鉴定错误。纳入的近平滑念珠菌复合体中的2株似平滑念珠菌(C.metapsilosis)以及光滑念珠菌复合体中的1株Candida nivariensis均能准确鉴定到了种水平。结论:Clin-TOF质谱系统在酵母样真菌鉴定方面已经可以基本满足临床需求。然而对于某些菌种的指纹图谱仍然需要进一步的优化和完善。

Objective: To assess the identification performance of domestic matrix-assisted laser desorption-ionization time of flight mass spectrometry(MALDI-TOF MS) Clin-TOF-Ⅱ system for clinical yeast. Methods: A total of 156 strains of 25 yeast species were included in this study and all the strains were selected from China Hospital Invasive Fungal surveillance Net. All the strains were accurately identified to species level by amplification and sequencing of internal transcribed spacer(ITS) region. And Clin-TOF MS system was adopted to implement direct smear method for identifying strains that were included in group. Results: In this study, the accurate identification rate of ClinTOF MS system for yeast could reach 95.5%(149/156). For Candida species, the accurate identification rate was 96.8%(122/126). Among 11 Cryptococcus neoformans strains, one strain was misidentified. In addition, two Candida metapsilosis strains(C. metapsilosis) of Candida parapsilosis complex, and one Candida nivariensis strain of Candida glabrata complex, that included in this study, were correctly identified to specie level. Conclusion: Clin-TOF MS system can basically meet the clinical needs in identifying yeast-like fungi. But it need be further optimized and improved for finger-print of some species.