| 摘要: |
| ［摘要］ 目的 探讨利用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）技术建立血流感染病原菌快速、准确的鉴定方法。方法 收集郑州大学附属儿童医院检验科2017-07～2017-12血培养仪阳性报警血培养瓶524个，抽吸血培养瓶中血液至血清分离胶管，采用差速离心法富集细菌，利用MALDI-TOF MS对富集后的菌液进行快速鉴定，并与传统培养24～48 h后形成的菌落最终鉴定结果进行比较。结果 阳性报警血培养瓶524个，496个为单菌株血流感染，16个为混合菌感染，12例血培养报警假阳性结果。在496个单菌株所致血流感染样本中，菌株的属、种鉴定符合率分别为98.6%（489/496）和95.8%（475/496）。其中，120株革兰阴性菌属、种鉴定符合率分别为99.2%（119/120）和98.3%（118/120）；376株革兰阳性菌属、种鉴定符合率分别为98.4%（370/376）和94.9%（357/376）。16个混合菌感染样本及12个血培养报警假阳性样本均未得到鉴定结果。结论 该研究利用MALDI-TOF MS对差速离心富集后的菌液进行直接鉴定，与传统的培养鉴定方法相比，对血流感染中主要病原菌的鉴定符合率较高，且方法快速、简便，成本低廉，有效缩短了检测时间，而且鉴定准确率高，适合在临床微生物实验室中推广应用。 |
| 关键词: 基质辅助激光解吸电离飞行时间质谱 血流感染 细菌鉴定 |
| DOI：10.3969/j.issn.1674-3806.2019.05.12 |
| 分类号:R 446.5 |
| 基金项目:河南省医学科技攻关计划（联合共建）项目（编号：2018020677） |
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| Application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in direct identification of pathogenic bacteria in bloodstream infection |
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FANG Pan-pan, YANG Jun-mei, YANG Jun-wen, et al.
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Zhengzhou Key Laboratory of Children′s Infection and Immunity, the Affiliated Children′s Hospital of Zhengzhou University(Children′s Hospital of Henan Province, Zhengzhou Children′s Hospital), Henan 450018, China
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| Abstract: |
| ［Abstract］ Objective To establish a rapid and accurate method for the identification of bloodstream infection pathogens by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS). Methods Five hundred and twenty-four blood culture bottles with positive alarm by blood culture instrument were collected in the Department of Clinical Laboratory of the Affiliated Children′s Hospital of Zhengzhou University during July 2017 to December 2017. The blood was drawn from the blood culture bottles and moved to serum separation rubber tubes, where bacteria were enriched and collected using differential centrifugation. The enriched bacterial liquid was identified rapidly by MALDI-TOF MS, and the results of colony-forming units were compared with those of colony-forming units formed by traditional bacterial culture in 24 to 48 hours. Results Of the 524 positive blood culture samples, 496 were single strain bloodstream infections, 16 mixed bacteria infections and 12 blood cultures false positive result of the alarm. Among the 496 single-strain bloodstream infections, the genus and species identification rates of the strains were 98.6%(489/496) and 95.8%(475/496) respectively. Among them, 120 strains were Gram-negative bacteria with a species identification rate being 99.2%(119/120) and 98.3%(118/120), and 376 strains were Gram-positive genus with a species identification rate being 98.4%(370/376) and 94.9%(357/376). No identification results were obtained in 16 cases of mixed bacteria infection and 12 blood cultures with false positive alarms. Conclusion MALDI-TOF MS is used to directly identify the bacterial liquid after differential centrifugation. Compared with the traditional culture identification method, MALDI-TOF MS has higher identification accuracy rate of the main pathogens in bloodstream infections, and MALDI-TOF MS is a fast, simple and low-cost method. MALDI-TOF MS can effectively shorten the time of detection and has high accuracy of identification, and is suitable to be applied in a clinical microbiology laboratory. |
Key words: Matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS)
Bloodstream infection Bacterial identification |
