MALDI-TOF MS技术在鉴定临床少见非发酵菌中的应用

Application of matrix assisted laser desorption ionization time of flight mass spectrometry technique for identification of rare non-fermentative bacteria in clinic

摘要:

摘要：目的  评价基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS）技术在快速鉴定临床少见非发酵菌中的应用价值。方法  选取2013年7月-2016年10月安徽医科大学第一附属医院检验科分离的67株临床少见非发酵菌，包括痰液分离的21株，尿液分离的13株，血液分离的9株，骨髓液分离的9株，分泌物分离的8株，腹透液分离的2株，脑脊液分离的1株，胆汁分离的1株，其他体液分离的3株。以16S核糖体RNA（16SrRNA）序列分析为金标准，比较MALDI-TOF MS与Vitek2 Compact鉴定系统鉴定的准确性。结果  67株临床少见非发酵菌中，MALDI-TOF MS将66株（98.5%）鉴定到种水平，1株（1.5%）鉴定到属水平；Vitek2 Compact鉴定系统将59株（88.1%）鉴定到种水平，8株（11.9%）未能鉴定；67株少见非发酵菌均扩增到16SrRNA目的基因片段并成功测序，67株（100.0%）都成功鉴定到种水平。以16SrRNA序列分析为金标准，MALDI-
TOF MS和Vitek2 Compact鉴定系统正确鉴定到种水平准确性分别为98.5%（66/67）和88.1%（59/67）。结论  与传统的细菌生化反应方法相比，MALDI-TOF MS技术操作简便、耗时短、费用低，鉴定结果与16SrRNA序列分析的符合率高，可以提高临床对少见非发酵菌鉴定的准确率。

关键词:

基质辅助激光解析电离飞行时间质谱;非发酵菌;鉴定

Abstract:

 Abstract: Objective To evaluate the application value of matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) technique in the rapid identification of rare non-fermentative bacteria. Methods From July 2013 to October 2016, 67 clinical isolates of rare non-fermentative bacteria were collected from the First Affiliated Hospital of Anhui Medical University, which included 21 strains isolated from sputum, 13 strains from urine, 9 strains from blood, 9 strains from bone marrow, 8 strains from secretions, 2 strains from peritoneal dialysis fluid, 1 strain from cerebrospinal fluid, 1 strain from bile, and 3 strains from other body fluids. According to the gold standard of 16SrRNA sequence analysis, the accuracy of the identification system of MALDI-TOF MS and Vitek2 Compact was compared. Results In the 67 strains of bacteria, MALDI-TOF MS technique identified 66 strains (98.5%) to species level and 1 strains (1.5%) to genus level; while Vitek2 Compact identified 59 strains (88.1%) to species level, and 8 strains (11.9%) failed to identify. 16SrRNA gene fragments were amplified from the 67 strains of experimental bacteria and successfully sequenced, all of the strains were identified to species level. Using 16SrRNA sequence analysis as the gold standard, the accuracy of MALDI-TOF MS system and Vitek2 Compact system for identification at the species level was 98.5% (66/67) and 88.1% (59/67) respectively. Conclusions Compared with traditional bacteria biochemical reaction method, MALDI-TOF MS technique is simple, rapid and inexpensive. Its accuracy of identification result is highly consistent with that of 16SrRNA sequence analysis, MALDI-TOF MS technique can improve the accuracy of clinical identification of non-fermentative bacteria.

Key words:

matrix assisted laser desorption ionization time of flight mass spectrometry; non-fermentative bacteria; identification