Simple Ciprofloxacin Resistance Test and Determination of Minimal Inhibitory Concentration within 2 h Using Raman Spectroscopy
Simple Ciprofloxacin Resistance Test and Determination of Minimal Inhibitory Concentration within 2 h Using Raman Spectroscopy
复制标题
DOI：
10.1021/acs.analchem.7b03800
复制
发表时间：
2018-02-06
影响因子：
7.4
通讯作者：
Neugebauer, Ute
中科院分区：
文献类型：
--
作者：
Kirchhoff, Johanna;Glaser, Uwe;Neugebauer, Ute
耐药细菌正在全球范围内蔓延，这使得快速的抗生素敏感性测试和确定最低抑菌浓度(MIC)成为迫切需要，以及时选择适当的抗生素治疗，从而改善患者的预后，同时避免不适当的治疗以及不必要的广谱抗生素的使用，这将助长耐药细菌的进一步传播。在这里，介绍了一种简单而快速的基于拉曼光谱的方法来确定抗菌药的敏感性，并在仅2小时的总分析内确定MIC，与目前用于诊断的已建立的表型方法相比，大大节省了时间。样品制备既快速又容易，可与目前建立的测试相媲美。使用介电芯片可以在微米大小的区域内自动收集细菌，以便直接从细菌悬液中进行高质量的拉曼测量。新的拉曼光谱MIC测试对13株临床分离的大肠埃希菌进行了验证，这些菌株显示出广泛的环丙沙星耐药性水平，并从血液感染患者中收集。微拉曼光谱仅在90min后就能检测到环丙沙星诱导的大肠杆菌的变化。主成分分析和简单计算的1458和1485 cm(-1)处的拉曼标记带的比值显示出明显的浓度依赖效应。用新的拉曼方法测定的MIC值与参考方法(肉汤微量稀释法、VITEK-2、E-TEST)测得的MIC值非常一致，并可用于根据EUCAST提供的临床断点将MIC值划分为敏感、中等或耐药。
Resistant bacteria are spreading worldwide, which makes fast antibiotic susceptibility testing and determination of the minimal inhibitory concentration (MIC) urgently necessary to select appropriate antibiotic therapy in time and, by this, improve patient's outcome and, at the same time, avoid inappropriate treatment as well as the unnecessary use of broad spectrum antibiotics that would foster further spread of resistant bacteria. Here, a simple and fast Raman spectroscopy-based procedure is introduced to identify antimicrobial susceptibilities and determine the MIC within only 2 h total analysis, marking a huge time savings compared to established phenotypic methods nowadays used in diagnostics. Sample preparation is fast and easy as well as comparable to currently established tests. The use of a dielectrophoresis chip allows automated collection of the bacteria in a micron-sized region for high-quality Raman measurement directly from bacterial suspensions. The new Raman spectroscopic MIC test was validated with 13 clinical E. coli isolates that show a broad range of ciprofloxacin resistance levels and were collected from patients with blood-stream infection. Micro-Raman spectroscopy was able to detect ciprofloxacin-induced changes in E. coli after only 90 min interaction time. Principal component analysis as well as a simple computed ratio of the Raman marker bands at 1458 and 1485 cm(-1) show a clear concentration-dependent effect. The MIC values determined with the new Raman method are in good agreement with MICs obtained by reference methods (broth microdilution, Vitek-2, E-test) and can be used to provide a classification as sensitive, intermediate, or resistant using the clinical breakpoints provided by EUCAST.