摘要：目的 构建MALDI-TOF MS自建数据库并评价其对非结核分枝杆菌鉴定的应用价值。方法 以hsp65、rpoB和16S DNA同源序列测序确定NTM菌种信息，MALDI-TOF MS以改良甲酸提取法为前处理方法，对自建数据库用菌株采集预测图谱并构建自建数据库。以“自建数据库+MBT DB5989数据库”鉴定NTM为实验组，“MBT DB5989数据库”鉴定NTM为对照组，以分子测序结果为金标准，评估MALDI-TOF MS自建数据库对NTM鉴定的应用价值。结果 10种64株待检NTM，对照组鉴定率（30/64）46.9%，实验组鉴定率（59/64）92.2%，X2=31.014，P<0.001；剔除MBT DB5989数据库缺失的NTM后，6种36株待检NTM，对照组鉴定率（30/36）83.3%，实验组鉴定率（35/36）97.2%, X2=3.956，P=0.053。4株类戈登分枝杆菌，实验组2株鉴定错误，对照组4株鉴定错误，使用Mycobacteria Library 5.0数据库，3株鉴定错误。结论 MALDI-TOF MS自建数据库可对MBT DB5989数据库进行完善，使其具备对MBT DB5989数据库外NTM的鉴定能力，提升MALDI-TOF MS的鉴定效能，但MALDI-TOF MS对类戈登分枝杆菌鉴定能力不足，仍需其他方法辅助鉴定。
Abstract: Objective To construct the matrix-assisted laser desorption ionization time-of-fight mass spectrometry ( MALDI-TOF MS)in-house database and evaluate its application value in the identifceation of non- tuberculous mycobacterium ( NTM ). Methods Seventy-two NTM clinical isolates were ollected during January 2018 and May 2021, and were identifed by the direct homologous sequencealignment and MALDI-TOF MS, respectively. The MALDI-TOF MS method for the idenifcation of NTM was further divided into the experimental group and control group，which was based on the " in-house database + MBT DB5989 database" and " MBT DB5989 data- base"，respectively. The identification coincidence rate of the two groups was compared and the application efficiency of MALDI-TOFMS in-house database for the identification of NTM was evaluated. Results Using the results of molecular identification as the gold standard, the coincidence rates of the control group and experimental group were51 .61% (32/62) and 95. 16% (59/62), respectively, and the ltter was signifcantly higher than the former (x2 = 30.102, P<0.001 ). After removing the NTM stains missing in the MBT DB5989 database, the coincidence rates of the control group and experimental group were 86.48% ( 32/37) and 97.30% (36/37), respectively, with no statistical significance between them (X2 =2.902, P=0.088 ). One strain of Mycobacterium paragordonae in the experimental goup was inorrectly identified as Mycobacterium gordonae. Conclusion The selection of MALDI-TOF MS databases directly affects the identification results of NTM, and the in-house database can improve the efficiency of MBT DB5989 database for the identification of NTM.
徐茂锁,刘亚隽,张慧,周聪,齐伟强,申春梅. MALDI-TOF MS自建数据库对非结核分枝杆菌鉴定的应用价值[J].临床检验杂志,2022,40(03):194-199复制