Percoll分离法联合MALDI-TOF MS直接鉴定血培养专性厌氧菌阳性标本的应用价值  

Direct identification of specific anaerobes positive blood culture sample by MALDI-TOF MS combined with Percoll density gradient contrifugation method

作　　者：梁林 幸雯 张京[2] 陆必超 丁秀荣[3] 刘志忠[2] LIANG Lin;XING Wen;ZHANG Jing;LU Bichao;DING Xiurong;LIU Zhizhong(School of Rehabilitation Medicine,Capital Medical University,Beijing 100069,China;Department of Clinical Laboratory,Beijing Bo′ai Hospital,China Rehabilitation Research Center,Beijing 100068,China;Department of Clinical Laboratory,Beijing You′an Hospital Affiliated to Capital Medical University,Beijing 100069,China)

机构地区：[1]首都医科大学康复医学院,北京100069 [2]中国康复研究中心北京博爱医院检验科,北京100068 [3]首都医科大学附属北京佑安医院检验科,北京100069

出　　处：《国际检验医学杂志》2021年第19期2324-2328,共5页International Journal of Laboratory Medicine

基　　金：北京市科技计划项目(Z181100001618015)。

摘　　要：目的评价Percoll分离法联合基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)直接鉴定血培养专性厌氧菌阳性标本中的应用价值。方法收集2018年3月至2020年9月血培养中单独厌氧瓶阳性标本,用Percoll分离法和十二烷基硫酸钠(SDS)洗涤法两种方法对标本进行菌体富集和纯化处理,采用MALDI-TOF MS对标本进行直接鉴定,以转种后菌落鉴定结果为标准,对两种不同前处理方法的鉴定准确率进行比较。结果共有71份血培养专性厌氧菌阳性标本纳入研究,采用Percoll分离法处理标本,专性厌氧菌“种”水平鉴定准确率为84.5%,其中革兰阴性菌的“种”水平鉴定准确率为80.0%,革兰阳性菌的“种”水平鉴定准确率为87.8%。采用SDS洗涤法处理标本,专性厌氧菌的“种”水平鉴定准确率为60.6%,其中革兰阴性菌的“种”水平鉴定准确率为46.7%,革兰阳性菌的“种”水平鉴定准确率为70.7%。与SDS洗涤法相比,采用Percoll分离法处理标本明显提高了MALDI-TOF MS对革兰阴性菌的鉴定准确率(χ^(2)=7.177,P=0.007)。结论使用Percoll分离法处理血培养专性厌氧菌阳性标本,用于MALDI-TOF MS直接鉴定,可明显提高专性厌氧菌特别是革兰阴性厌氧菌的鉴定准确率,且操作简便,成本低,适合在临床微生物实验室中应用。Objective To evaluate the application value of Percoll density gradient centrifugation method in the direct identification of specific anaerobes positive blood culture samples by matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS).Methods Blood culture samples with only anaerobic bottle positive were included in the study from March 2018 to September 2020.Percoll density gradient centrifugation method and sodium dodecyl sulfate(SDS)washing method were used to enrich and purify the anaerobes from positive blood culture respectively,both followed by direct identification by MALDI-TOF MS.According to the standard identification of pure colonies after inoculation,the identification accuracy of the two pretreatment methods were then compared.Results A total of 71 blood culture samples with specific anaerobes positive were collected.The identification accuracy rate of Percoll density gradient centrifugation method in identification of anaerobes in species level was 84.5%,with the Gram-negative and Gram-positive bacteria 80.0%and 87.8%respectively.The identification accuracy rate of SDS washing method in identification of anaerobes in species level was 60.6%,with the Gram-negative and Gram-positive bacteria 46.7%and 70.7%respectively.Compared with the SDS washing method,the way of Percoll density gradient centrifugation method to treat the samples significantly improved the identification accuracy of Gram-negative bacteria by MALDI-TOF MS(χ^(2)=7.177,P=0.007).Conclusion Using Percoll density gradient centrifugation method to treat specific anaerobes positive blood culture samples for direct identification by MALDI-TOF MS can significantly improve the identification accuracy of specific anaerobes,especially Gram-negative anaerobic bacteria.It has the advantages of simple operation and low cost.It is suitable for application in clinical microbiology laboratories.

关 键 词：十二烷基硫酸钠 细胞分离液 基质辅助激光解析电离飞行时间质谱 血培养 厌氧菌 

分 类 号：R446.5[医药卫生—诊断学]