摘要
目的探讨尿流式细胞术联合基质辅助激光解析电离飞行时间质谱(Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry,MALDI-TOF MS)直接鉴定尿标本病原菌的应用。方法收集2017年1-10月住院及门诊泌尿系统感染患者送检的清洁中段尿阳性标本234份。所有样本均通过尿流式细胞仪(UF-1000i)进行菌量计数;根据主要病原菌不同浓度的菌量,由MALDI-TOF MS判断分值来判定结果的可靠性。MALDI-TOF MS技术直接鉴定中段尿标本中大肠埃希菌(UF-1000i细菌计数>10~5个/ml)与Biotyper数据库中的大肠埃希菌最佳匹配图谱进行比较。MALDI-TOF MS技术鉴定血琼脂平板上与中段尿不同菌量计数的大肠埃希菌的光谱比较。结果 MALDI-TOF MS直接法鉴定大肠埃希菌为可靠鉴定的最低菌量浓度为6×10~4个/ml,铜绿假单胞菌最低菌量浓度为1×10~5个/ml,金黄色葡萄球菌最低菌量浓度为3×10~5个/ml,粪肠球菌最低菌量浓度为5×10~5个/ml。MALDI-TOF MS技术直接鉴定中段尿标本中大肠埃希菌(UF-1000i细菌计数>10~5个/ml),鉴定分值为2.245。利用MALDI-TOF MS直接鉴定与Vitek2-Compact全自动细菌鉴定进行对比,鉴定结果一致率为90.39%(207/229);中段尿培养为2种菌时,MALDI-TOF MS直接鉴定法鉴定结果为不可靠。MALDI-TOF MS直接法鉴定结果中鉴定到种水平207例占90.39%(207/229),鉴定到属水平216例94.32%(216/229),5.68%(13/229)MALDI-TOF MS未提供可靠的鉴定结果。结论尿流式细胞术与MALDITOF MS技术联合直接鉴定尿液中病原菌,是一种可靠细菌鉴定的新方法,其快速准确的鉴定,可为临床治疗提供病原学依据,具有一定的临床价值。
OBJECTIVE To investigate the application of urinary flow cytometry combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry（MALDI-TOF MS）in the direct identification of pathogens in urine samples.METHODS A total of 234 urine samples were collected from inpatients and outpatients with urinary tract infection from Jan. 2017 to Oct. 2017.Bacterial counts including Escherichia coli,Pseudomonas aeruginosa,Staphylococcus aureus,Enterococcus faecalis were performed by uroflowcytometry（UF-1000 i）.Bacterial identification was implemented by Vitek2-Compact（Instrument for Automatic Microbial Identification）and MALDI-TOF MS.After the amount of bacteria in the urine was counted by UF-1000i,the score was determined by MALDI-TOF MS to evaluate the reliability of the results according to different concentrations of bacteria.The MALDI-TOF MS technique was used to directly identify E.coli（bacterial count 10~5 cells/ml by UF-1000i）in the midstream urine samples and the results were compared with the best matching map of E.coli in the Biotyper database.The results of identification for E.coli on the blood agar plates by MALDI-TOF MS technology were compared to the spectra of different bacteria count of E.coli in the urine samples.RESULTS We found that the minimum bacterial concentration of 6×10~4 cells/ml for E.coli,1×10~5 cells/ml for P.aeruginosa,3×10~5 cells/ml for S.aureus,5×10~5 cells/ml for E.faecalis could be directly and reliably identified by MALDI-TOF MS.The score for direct identification of E.coli（Bacterial count10~5 cells/ml by UF-1000 i）in urinary specimens was2.245 by MALDI-TOF MS.There was a consistence of 90.39%（207/229）between the results of direct identification by MALDI-TOF MS and those by Vitek2-Compact.When there were 2 kinds of bacteria in the midstream urine,the result of MALDI-TOF MS was taken as unreliable.Overall,207 isolates accounting for 90.39%（207/229）were identified to species,216 accounting for 94.32%（216/229）were identified to gen
作者
张肖
郝天波
吴鸿
吴继华
沈昊
杨鸿林
沈国荣
顾兵
ZHANG Xiao;HAO Tian-bo;WU Hong;WU Ji-hua;SHEN Hao;YANG Hong-lin;SHEN Guo-rong;GU Bing(Wujiang First People＇s Hospital of Suzhou,Suzhou,Jiangsu 215200,China)
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2018年第20期3045-3049,3055,共6页
Chinese Journal of Nosocomiology
基金
国家自然科学基金资助项目(81471994)
