Novel Approach for Differentiating Shigella Species and Escherichia coli by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
Novel Approach for Differentiating Shigella Species and Escherichia coli by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
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DOI：
10.1128/jcm.01526-13
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发表时间：
2013-11-01
影响因子：
9.4
通讯作者：
Fisher, Mark A.
中科院分区：
文献类型：
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作者：
Khot, Prasanna D.;Fisher, Mark A.
志贺氏菌属与大肠杆菌密切相关，常规基质辅助激光解吸/电离飞行时间质谱 (MALDI-TOF MS) 无法可靠地区分它们。通常使用生化和血清学方法来区分这些物种；然而，“无活性”的大肠杆菌分离株在生化上与志贺氏菌非常相似，因此提出了更大的诊断挑战。我们使用 ClinProTools (Bruker Daltonics) 软件来发现 MALDI-TOF MS 生物标志物峰，并基于遗传算法生成分类模型来区分志贺氏菌属和大肠杆菌。六十六志贺氏菌属。使用72个大肠杆菌分离株生成并测试分类模型，最佳模型包含15个属级分类生物标志物峰和12个种级分类生物标志物峰。我们能够在物种水平上正确识别 90% 的大肠杆菌和志贺氏菌临床分离株。只有 3% 的测试菌株被错误识别。这种新颖的 MALDI-TOF MS 方法使实验室能够简化大肠杆菌和志贺氏菌属物种的鉴定。
Shigella species are so closely related to Escherichia coli that routine matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) cannot reliably differentiate them. Biochemical and serological methods are typically used to distinguish these species; however, "inactive" isolates of E. coli are biochemically very similar to Shigella species and thus pose a greater diagnostic challenge. We used ClinProTools (Bruker Daltonics) software to discover MALDI-TOF MS biomarker peaks and to generate classification models based on the genetic algorithm to differentiate between Shigella species and E. coli. Sixty-six Shigella spp. and 72 E. coli isolates were used to generate and test classification models, and the optimal models contained 15 biomarker peaks for genus-level classification and 12 peaks for species-level classification. We were able to identify 90% of E. coli and Shigella clinical isolates correctly to the species level. Only 3% of tested isolates were misidentified. This novel MALDI-TOF MS approach allows laboratories to streamline the identification of E. coli and Shigella species.