摘要 目的了解基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)直接快速检测血培养报阳样本的可行性。方法收集同济大学附属同济医院报阳血培养样本682例,从血培养瓶直接抽取血液至分离胶采血管离心富集细菌后,采用MALDI-TOF MS进行直接鉴定(快速质谱法)。同时对报阳血培养标本进行涂片镜检及转种培养后,分别采用Vitek 2 Compact自动化鉴定药敏仪及MALDI-TOF MS对培养菌落进行鉴定,比较两者鉴定结果的一致性,结果不一致的菌株采用16S rDNA基因测序进行验证。结果682例血培养阳性样本中,有664例检出单数菌,其中539例(81.2%)快速质谱法可准确鉴定(种/属),122例(18.4%)未鉴定出(种/属),仅3例(0.5%)鉴定错误,分别为泛菌属、肺炎克雷伯菌和头状葡萄球菌。664株菌株中,革兰阴性菌367株,革兰阳性菌286株,念珠菌11株,以转种培养后质谱鉴定结果为标准,革兰阴性菌、革兰阳性菌、念珠菌快速质谱法的鉴定准确率(种/属)分别为85.8%/6.0%、65.0%/3.1%、63.6%/0;革兰阴性杆菌的鉴定准确率显著高于革兰阳性球菌和真菌,差异有统计学意义(χ2=57.967,P<0.01;χ2=7.21,P<0.05)。革兰阴性菌中,肠杆菌科、非发酵菌及其他革兰阴性菌鉴定准确率(种/属)分别为89.0%/5.0%、65.0%/10.0%、66.7%/22.2%。革兰阳性菌中,葡萄球菌属、肠球菌属、链球菌属和其他革兰阳性菌鉴定准确率(属/种)分别为70.9%/1.1%、71.4%/2.4%、40.5%/10.8%、50%/7.1%。有18例样本检出复数菌,快速质谱法从其中14例中检出复数菌,鉴定准确率为77.8%,均只鉴定到种。结论快速质谱法检测血培养报阳样本具有可行性,对单数菌的鉴定错误概率非常低,且对临床常见病原菌鉴定准确率均>70%。但对复数菌鉴定效果不佳。临床可根据实际需求选择合适的细菌鉴定方法。 Objective To investigate the feasibility of matrix-assisted laser desorption ionization time-offlight mass spectrometry(MALDI-TOF MS)in the direct and rapid detection of blood culture positive specimens.Methods Totally,682 positive blood culture specimens were collected from Tongji Hospital.Blood was directly extracted from blood culture bottle and centrifuged in separated gel collecting tube.The centrifugally enriched bacteria were identified by MALDI-TOF MS.They were examined by slide review for the transmitted inoculation culture simultaneously.The culture colonies were identified by Vitek 2 Compact automatic microbial identification system and MALDI-TOF MS.The consistency of the identification results was compared.The strains with different results were verified by 16S rDNA gene sequencing.Results Among 682 blood culture positive specimens,664 cases were infected by single bacterium,and 539 strains(81.2%)were identified by MALDI-TOF MS,122 strains(18.4%)were not identified(species/genus),but only 3 strains(0.5%)were identified incorrectly(species/genus),including 1 case of Pantoea,1 case of Klebsiella pneumoniae and 1 case of Staphylococcus capitis.The 664 strains were infected by single bacterium,including 367 strains of Gram-negative bacteria,286 strains of Grampositive bacteria and 11 strains of Candidia albicans.Compared with the results of traditional colony identification,the accuracies(species/genus)of MALDI-TOF MS were 85.8%/6%,65%/3.1%and 63.6%/0%,respectively.The accuracy of Gram-negative bacteria was higher than those of Gram-positive bacteria and fungi(χ2=57.967,P<0.01;χ2=7.21,P<0.05).Among Gram-negative bacteria,the accuracies(species/genus)of Enterobacteriaceae,non-fermentative bacteria and other Gram-negative bacteria were 89.0%/5.0%,65.0%/10.0%and 66.7%/22.2%,respectively.Among Gram-positive bacteria,the accuracies(species/genus)of Staphylococcus,Enterococcus,Streptococcus and other Gram-positive bacteria were 70.9%/1.1%,71.4%/2.4%,40.5%/10.8%and 50%/7.1%,respectively.There were 18 cas
机构地区 同济大学附属同济医院检验科
出处 《检验医学》 CAS 2021年第4期424-429,共6页 Laboratory Medicine
关键词 基质辅助激光解吸电离飞行时间质谱 直接快速检测 血培养 Matrix-assisted laser desorption ionization time-of-flight mass spectrometry Direct and rapid detection Blood culture
