Introduction

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been introduced for bacterial identification. The ASTA MicroIDSys system (ASTA, Suwon, Korea) is a new MALDI-TOF MS system developed for species identification of microorganisms. We evaluated the performance of MicroIDSys against clinical isolates of anaerobic bacteria.

Material and methods

A total of 370 non-duplicated clinical isolates of anaerobic bacteria were tested in this study. Bacterial identification with MicroIDSys was performed with a direct smear method, and measured spectra were analyzed using respective software. The results of MicroIDSys were compared with the results of Bruker Biotyper and 16S rRNA sequencing.

Results

The overall agreement rates for the 370 clinical isolates (34 genera and 99 species) were 95.4% (353/370) at the genus level and 91.6% (n = 340) at the species level. Only 17 isolates were incorrectly identified at the genus level: five misidentifications and 12 unidentifications. The MicroIDSys system exhibited excellent performance in the identification of clinically relevant bacterial species. Most of the Bacteroides isolates (98.0%, 99/101) and all of the Clostridium difficile (100%, n = 11), Clostridium perfringens (100%, n = 10), Finegoldia magna (100%, n = 11), and Parvimonas micra (100%, n = 10) isolates were correctly identified at the species level.

Conclusion

The MicroIDSys system proved useful in the identification of anaerobic bacteria, especially clinically relevant species. This system could be of use in clinical microbiology laboratories as a primary tool for identifying anaerobic bacteria.

中文翻译：

---

新型基质辅助激光解吸/电离飞行时间质谱仪ASTA MicroIDSys系统的性能评估，可针对厌氧菌临床分离株进行细菌鉴定。

介绍

引入了基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）进行细菌鉴定。ASTA MicroIDSys系统（ASTA，水原，韩国）是一种新的MALDI-TOF MS系统，用于鉴定微生物。我们评估了MicroIDSys对厌氧菌临床分离株的性能。

材料与方法

在这项研究中，共测试了370个厌氧细菌的非重复临床分离株。用MicroIDSys进行的细菌鉴定采用直接涂片法进行，并使用各自的软件对测得的光谱进行分析。将MicroIDSys的结果与Bruker Biotyper和16S rRNA测序的结果进行了比较。

结果

370种临床分离株（34属和99种）的总体同意率在属水平上是95.4％（353/370），在种水平上是91.6％（n = 340）。在属水平上仅错误地鉴定出17个分离株：5个错误鉴定和12个未鉴定。MicroIDSys系统在鉴定临床相关细菌物种方面表现出出色的性能。多数分离的拟杆菌（98.0％，99/101）和所有艰难梭菌（100％，n = 11），产气荚膜梭菌（100％，n = 10），大花Fine（100％，n = 11）以及在物种一级正确鉴定了帕氏单胞菌（100％，n = 10）的分离株。

结论

事实证明，MicroIDSys系统可用于鉴定厌氧细菌，尤其是临床相关物种。该系统可以在临床微生物学实验室中用作鉴定厌氧细菌的主要工具。