MALDI-TOF MS技术在鲍曼不动杆菌鉴定及同源性分析中的应用

Identification and homology analysis of Acinetobacter baumannii by use of matrix-assisted laser desorption / ionization time-offlight mass spectrometry

目的评价基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)技术对我院鲍曼不动杆菌属的鉴定及同源性分析的能力。方法对2014年9月至2015年2月我院29株经PhoneixTM100全自动微生物鉴定仪鉴定为鲍曼不动杆菌属的菌株进行MALDI-TOF MS鉴定,用MALDI-Biotyper软件进行同源性分析,并用16S rRNA基因测序进行验证。结果 MALDI-TOF MS鉴定结果为鲍曼不动杆菌(Acinetobacter baumannii)26株,院内不动杆菌(Acinetobacter nosocomialis)3株。MALDI-TOF MS鉴定为院内不动杆菌的3株菌株的16S rRNA基因测序结果显示,2株为院内不动杆菌,1株为鲍曼不动杆菌。26株质谱鉴定为鲍曼不动杆菌的菌株分为2大簇(Ⅰ型,Ⅱ型),Ⅱ型又分为2小簇(Ⅱa、Ⅱb)。Ⅰ型、Ⅱ型分布在我院4个病区。结论MALDI-TOF MS技术鉴定鲍曼不动杆菌精准,可以鉴别鲍曼不动杆菌和院内不动杆菌。MALDI-Biotyper数据库软件进行同源性分析十分快捷。

Objective To investigate the application of matrix-assisted laser desorption / ionization time-of-flight mass spectrometry（ MALDI-TOF MS） in the identification and homology analysis of Acinetobacter baumannii. Methods Twenty-nine Acinetobacter baumannii isolates identified by PhoneixTM100 automatic microbial identification system in our hospital during Sep 2014 to Feb 2015 were evaluated by MALDI-TOF MS again. Meanwhile,the homology of Acinetobacter baumannii was analyzed by MALDI-Biotyper software,and verified by 16 S rRNA sequencing. Results Twenty-nine isolates were identified to be Acinetobacter baumannii for 26 and Acinetobacte nosocomialis for 3 by MALDI-TOF MS,and the latter 3 were further verified to be Acinetobacte nosocomialis for 2 and Acinetobacter baumannii for 1 by 16 S rRNA sequencing. The 26 isolates identified to be Acinetobacter baumannii by MALDI-TOF MS were divided into 2 big clusters,type Ⅰ and type Ⅱ,by homology analysis,and type Ⅱ was divided into 2 small clusters,type Ⅱa and type Ⅱb,again. Type Ⅰ and type Ⅱ isolates were distributed in 4 wards of our hospital. Conclusion MALDI-TOF MS may be used to identify Acinetobacter baumannii,and distinguish Acinetobacter nosocomialis from Acinetobacter baumannii. Moreover,MALDI-Biotyper software may be used to analyze the homology of Acinetobacter conveniently.