基于靶板甲酸直接提取法的MALDI-TOF MS鉴定棒状杆菌和类棒状菌群效能分析  

Effectiveness analysis of MALDI-TOF MS based on direct on-plate extraction of formic acid in identifying Corynebacterium and coryneform-like bacteria

作　　者：张宁梅 米思蓉[1] 屈宁[1] ZHANG Ningmei;MI Sirong;QU Ning(Department of Clinical Laboratory,the Affiliated Hospital of Yan'an University,Yan'an 716000,Shaanxi,China)

机构地区：[1]延安大学附属医院检验科

出　　处：《检验医学》2019年第8期746-751,共6页Laboratory Medicine

摘　　要：目的通过与API Coryne法比较,分析基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)鉴定棒状杆菌和类棒状菌群的效能。方法收集分离自50例患者临床样本的129株棒状杆菌和类棒状菌群分离株,通过基于靶板甲酸直接提取法的MALDI-TOF MS进行棒状杆菌和类棒状菌群鉴定,并以截断分数(种水平≥1.7,属水平≥1.5,无鉴定结果<1.5)为标准进行菌种的二次鉴定,同时采用API Coryne法鉴定,并对菌株16S rRNA基因的前500 bp进行测序,确定各分离株的种类。结果129株菌株16S rRNA基因的测序结果显示:95株为棒状杆菌,来源于13个物种;34株为类棒状菌群,来源于15个属。MALDI-TOF MS进行菌种鉴定时,以截断分数为标准,100%的棒状杆菌可被鉴定到属水平,98.9%的棒状杆菌可被鉴定到种水平;94.1%的类棒状菌群可被鉴定到属水平,88.2%的类棒状菌群可被鉴定到种水平。而API Coryne法能够鉴定84.2%的棒状杆菌至种水平,61.8%的类棒状菌群至属水平。结论相较于API Coryne法,基于靶板甲酸直接提取法的MALDI-TOF MS在鉴定棒状杆菌和类棒状菌群时效能更佳。Objective To evaluate the effectiveness of matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF MS)in identifying Corynebacterium and coryneform-like bacteria by comparing with API Coryne.Methods A total of 129 isolates of coryneform bacteria were collected from the clinical samples of 50 patients.The identification of Corynebacterium and coryneform-like bacteria was performed using MALDI-TOF MS based on direct on-plate extraction of formic acid and API Coryne,respectively.The isolates were identified with the cutoff scores(specie level≥1.7,genus level≥1.5 and no identification<1.5)for MALDI-TOF MS.The first 500 bp of the 16S rRNA gene of the above isolates was sequenced to determine the types of them.Results A total of 129 isolates of coryneform bacteria were isolated from the clinical samples of patients,and the first 500 bp of the 16S rRNA gene was sequenced.The results showed that 95 of them were Corynebacterium,covering 13 species,and 34 of them were coryneform-like bacteria,covering 15 genera.For MALDI-TOF MS bacterial identification,100%of Corynebacterium were identified as genus level,and 98.9%of them were identified as specie level.The 94.1%of coryneform-like bacteria were identified as genus level,and 88.2%of them were identified as specie level.However,API Coryne was able to identify 84.2%of Corynebacterium to the specie level and 61.8%of coryneform-like bacteria to the genus level.Conclusions MALDI-TOF MS based on formic acid direct on-plate extraction is more effective in identifying Corynebacterium and coryneform-like bacteria than API Coryne.

关 键 词：棒状杆菌 类棒状菌群 基质辅助激光解吸电离飞行时间质谱 API Coryne法 

分 类 号：R446.1[医药卫生—诊断学]