基质辅助激光解吸电离飞行时间质谱在动物源细菌耐药性监测中的研究应用

Application of Matrix-assisted Laser Desorption Ionization Time-off Flight Mass Spectrometry in Monitoring Drug Resistance of Animal-derived Bacteria

关键词:  基质辅助激光解析电离飞行时间质谱  大肠杆菌  肠球菌  耐药性

Key words:  MALDI-TOF MS  Escherichia coli  Enterococcus  drug resistance

摘要:

细菌鉴定是细菌耐药性监测过程中的重要工作环节之一，基质辅助激光解析电离飞行时间质谱(Matrix-assisted laser desorption ionization time-off flight mass spectrometry, MALDI-TOF MS)能够高效鉴定细菌。为了快速监测五家养殖场来源的大肠杆菌和肠球菌的临床耐药特征，本研究利用MALDI-TOF MS和微量肉汤稀释法，快速鉴定临床分离的大肠杆菌和肠球菌，并对其进行耐药表型检测。结果显示，MALDI-TOF MS实现了对临床分离菌株(31株大肠杆菌和34株肠球菌)的快速鉴定；鸡源大肠杆菌和肠球菌的耐药情况最为严重，其次为羊和牛。其中，鸡源的大肠杆菌均对四环素(100%)和氨苄西林(91.67%)耐药率最高，肠球菌对苯唑西林(62.07%)耐药率较高。研究结果表明，不同动物源细菌临床耐药性表型严重程度有所不同，与此同时，MALDI-TOF MS技术可以同时实现对动物源大肠杆菌和肠球菌的快速鉴定，值得在动物源细菌耐药性检测领域推广应用。

Abstract:

Bacterial identification is one of the important tasks in the process of bacterial drug resistance monitoring. Matrix-assisted laser desorption ionization time-off light mass spectrometry (MALDI-TOF MS) is a method to efficiently identify bacteria. In order to quickly monitor the clinical resistance characteristics of Escherichia coli and Enterococcus from five farms, MALDI-TOF MS and micro broth dilution method were used to quickly identify clinically isolated suspected Escherichia coli and Enterococcus, and performed resistance phenotype detection. The results showed that MALDI-TOF MS identified rapidly clinically isolated strains (31 strains of E. coli and 34 strains of Enterococcus); chicken-derived E. coli and Enterococcus had the most serious drug resistance, followed by sheep and cattle. Chicken-derived E. coli had the highest resistance rates to tetracycline (100%) and ampicillin (91.67%), and Enterococcus had higher resistance rates to oxacillin (62.07%). In summary, the severity of the clinical drug resistance phenotypes of different animal-derived bacteria was different. At the same time, the MALDI-TOF MS technology can simultaneously realize the rapid identification of animal-derived E. coli and Enterococcus, which is worthy of promotion and application in the field of animal-derived bacterial drug resistance detection.