基质辅助激光解析电离飞行时间质谱仪在快速鉴定临床酵母菌中的应用

Matrix-assisted laser desorption ionization-time of flight mass spectrometry for rapid identification of clinical isolates

目的目前酵母菌的实验室检测方法往往鉴定周期长、操作繁琐、阳性率低,不能满足临床快速诊断和及时治疗的需要。文中探讨基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption ionization-time of flight mass spectrometry,MALDI-TOF-MS)用于快速鉴定临床分离酵母菌的可行性。方法收集南京军区南京总医院2013年7-10月自临床标本分离的非重复酵母菌120株。分别使用MALDI-TOF-MS和Vitek 2-Compact全自动微生物分析系统或API酵母菌鉴定条进行鉴定,结果不一致的菌株采用ITS基因测序验证。结果 120株酵母菌中117株(97.5%)MALDI-TOF-MS正确鉴定到种水平,2株(1.7%)未给出鉴定结果,1株(0.8%)鉴定结果不一致的菌株经ITS基因测序确认,MALDI-TOF-MS和Vitek 2-Compact/API均鉴定错误。结论 MALDI-TOF-MS可以作为一个快速、准确和价廉的工具应用于临床酵母菌的鉴定。

Objective Laboratory tests of yeast, with their disadvantages of long identification, complicated operation, and low positive rate, cannot meet the needsof rapid diagnosis and timely treatment.This studyinvestigated the feasibility ofapplying matrix-assisted laser desorption ionization-time of flight mass spectrometry （ MALDI-TOF-MS） in rapid identification and clinical isolationof yeast strains. Methods A total of 120 clinical non-repetitive isolates were collected from clinical culture samples and identified by MALDI-TOF-MS and VITEK 2-Compact/API, respectively.The discordant results were resolved by ITS gene sequencing. Results Of the 120 yeast isolates analyzed, 117 （97.5%） were correctly identified at the species level by MALDI-TOF-MS, 1（0.8%） misidenti-fied, and 2 （ 1.7%） unidentified.ITS gene sequencing of the 3 isolates showed the coincidence rate to be 0（ 0/3） for MALDI-TOF-MS and Vitek 2-Compact/API. Conclusion MALDI-TOF-MScan be used as a rapid, accurate, and inexpensive tool for the identification of clinical yeast strains.