基质辅助激光解析电离飞行时间质谱对非结核分枝杆菌鉴定能力分析

Analyzing the ability of matrix assisted laser desorption ionization time of flight mass spectrometry in identification of nontuberculous mycobacteria

目的 分析基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)对非结核分枝杆菌的鉴定能力,研究MALDI-TOF MS数据库差异对非结核分枝杆菌鉴定能力的影响。方法 收集本院2018年1月-2020年8月临床分离的51株MPT64抗原检测阴性分枝杆菌,使用同源序列16S rDNA、hsp65和rpoB基因分析鉴定对比MALDI-TOF MS技术鉴定,以同源序列分析鉴定为金标准,分析MALDI-TOF MS对非结核分枝杆菌的鉴定能力,研究数据库DB_164_Mycobacteria Library 5. 0和Bruker MBT_DB5989对NTM的鉴定能力的差异。结果 MALDI-TOF MS对NTM鉴定符合率为92. 00%,鉴定失败率为8. 00%,无法鉴别胞内分枝杆菌和嵌合体分枝杆菌,1株类戈登分枝杆菌鉴定错误;MALDI-TOF MS数据库Bruker MBT_DB5989较DB_164_Mycobacteria Library 5. 0对NTM的鉴定能力差异有统计学意义(P<0. 05),鉴定率下降62. 00%。结论 MALDI-TOF MS技术可以快速有效地对NTM进行菌种鉴定,但对NTM某些种难以鉴别,MALDI-TOF MS数据库DB_164_Mycobacteria Library 5. 0更适合临床NTM分离株的鉴定。

Objective To analyze the ability of matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS)to identify non-tuberculous mycobacteria,and to explore the influence of MALDI-TOF MS database differences on the ability to identify non-tuberculous mycobacteria.Methods Fifty-one strains of MPT64 antigen-negative mycobacteria were collected in our hospital from January 2018 to August 2020.The homologous sequence 16S rDNA,hsp65 and rpoB gene analysis and identification were compared with the identification by MALDI-TOF MS technology.Sequence analysis was identified as the gold standard,and the identification ability of MALDI-TOF MS for non-tuberculous mycobacteria was analyzed,and the difference between the identification ability of DB」64_Mycobacteria Library 5.0 and Bruker MBT_DB5989 for NTM was studied.Results MALDI-TOF MS had a 92.00%compliance rate for NTM identification,and an identification failure rate of 8.00%.It was impossible to distinguish between Mycobacterium intracellulare and Mycobacterium chimera^and the identification of one strain of Mycobacterium paragordonae was wrong;the difference of MALDI-TOF MS database Bruker MBT_DB5989 in NTM identification ability was statistically significant,compared with DB_164_Mycobacteria Library 5.0(P<0.05),and the identification rate decreased by 62.00%.Conclusion MALDI-TOF MS technology can quickly and effectively identify NTM strains,but it is difficult to identify some species of NTM.The MALDI-TOF MS database DB_164_Myco-bacteria Library 5.0 is more suitable for the identification of clinical NTM isolates.