基质辅助激光解吸电离飞行时间质谱仪鉴定临床分离菌的应用评估

Performance of matrix assisted laser desorption ionization time of flight biotyper system in clinical bacteria identification

目的使用布鲁克基质辅助激光解吸电离飞行时间质谱仪对临床分离的病原菌进行鉴定并评价其准确性。方法收集福建医科大学附属第一医院2015年11月至2016年12月分离得到的21270株病原菌，分别以布鲁克质谱仪以及VITEK-Ⅱ／API表型鉴定系统进行鉴定，并以分子生物学结果为金标准，验证鉴定结果的准确性。结果对临床常见病原菌，质谱系统的检出率〉95％、表型系统的检出率〉90％，具有较高的一致性。对43株厌氧菌，质谱有90．7％能鉴定到种，97．7％被鉴定到属。表型系统有65．1％被鉴定到种，69．8％被鉴定到属，差异有统计学意义（x^2=6．76，P〈0．01）；1558株真菌中，丝孢酵母和念珠菌的检出率差异均无统计学意义（均P〉0．05），质谱对78株丝状真菌鉴定的准确率为76％；18株放线菌、诺卡菌、分枝杆菌和军团菌都能被鉴定到属。结论蛋白质谱鉴定技术操作简单、灵敏度高，能够对临床分离的常见病原菌、厌氧菌、真菌等提供快速、准确的鉴定。

Objective To evaluate the performance of MALDI Biotyper system in identification of clinically isolated pathogens so as to provide a new rapid identification method. Methods Total 21 270 pathogens strains, isolated from the First Affiliated Hospital of Fujian Medical Universityduring Nov. 2015 to Dec. 2016, were identified by VITEK-I1, API and MALDI Biotyper system, respectively. The isolated strains were confirmed by DNA sequencing. Results The identification of common bacteria with MALDI Biotyper and phenotypic system is highly consistent （ 〉 95% and 〉 90% ）. Among 43 strains of anaerobic bacteria, MALDI Biotyper could identify 90. 7% bacteria to species level and 97. 7% bacteria to genus level with the statistical significance （ x^2 = 6. 76, P 〈 0. 01 ）, while phenotypic system only identified 65. 1% bacteria to species and 69. 8% bacteria to genus. Also, no statistical significance was shown for Trichosporon and Candida（P 〉 0. 05 ）. MALDI Biotyper could identify 76% filamentous fungi and all of Actinomycetes, Nocardia, Mycobacterium and Legionella to genus level. Conclusions MALDI Biotyper is an easy performed, sensitive method for the identification of clinically isolated pathogens. Additionally, the prctreatment and reference database has the effect on identification.