Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States.
Bindley Bioscience Center , Purdue University , West Lafayette , Indiana 47907 , United States.
Anal Chem. 2019 Sep 3;91(17):11349-11354. doi: 10.1021/acs.analchem.9b02465. Epub 2019 Aug 20.
The worldwide increase in antimicrobial resistance is due to antibiotic overuse in agriculture and overprescription in medicine. For appropriate and timely patient support, faster diagnosis of antimicrobial resistance is required. Current methods for bacterial identification rely on genomics and proteomics and use comparisons with databases of known strains, but the diagnostic value of metabolites and lipids has not been explored significantly. Standard mass spectrometry/chromatography methods involve multiple dilutions during sample preparation and separation. To increase the amount of chemical information acquired and the speed of analysis of lipids, multiple reaction monitoring profiling (MRM-Profiling) has been applied. The MRM-Profiling workflow includes a discovery stage and a screening stage. The discovery stage employs precursor (PREC) ion and neutral loss (NL) scans to screen representative pooled samples for functional groups associated with particular lipid classes. The information from the first stage is organized in precursor/product ion pairs, or MRMs, and the screening stage rapidly interrogates individual samples for these MRMs. In this study, we performed MRM-Profiling of lipid extracts from four different strains of cultured with amoxicillin or amoxicillin/clavulanate, a β-lactam and β-lactamase inhibitor, respectively. tests, analysis of variance and receiver operating characteristic (ROC) curves were used to determine the significance of each MRM. Principal component analysis was applied to distinguish different strains cultured under conditions that allowed or disallowed development of bacterial resistance. The results demonstrate that MRM-Profiling distinguishes the lipid profiles of resistant and nonresistant strains.
世界范围内抗生素耐药性的增加是由于农业中抗生素的过度使用和医学上的过度处方。为了对患者进行适当和及时的支持，需要更快地诊断抗生素耐药性。目前用于细菌鉴定的方法依赖于基因组学和蛋白质组学，并使用与已知菌株数据库的比较，但代谢物和脂质的诊断价值尚未得到充分探索。标准的质谱/色谱方法在样品制备和分离过程中需要进行多次稀释。为了增加所获得的化学信息的数量和分析脂质的速度，已经应用了多重反应监测谱分析 (MRM-Profiling)。MRM-Profiling 工作流程包括发现阶段和筛选阶段。发现阶段采用前体 (PREC) 离子和中性丢失 (NL) 扫描，以筛选与特定脂质类相关的功能基团的代表性混合样品。第一阶段的信息组织在前体/产物离子对或 MRM 中，筛选阶段快速检测单个样品中的这些 MRM。在这项研究中，我们对分别用阿莫西林或阿莫西林/克拉维酸（一种β-内酰胺和β-内酰胺酶抑制剂）培养的四种不同菌株的脂质提取物进行了 MRM-Profiling。采用 t 检验、方差分析和接收器操作特征 (ROC) 曲线来确定每个 MRM 的显著性。主成分分析用于区分在允许或不允许细菌耐药性发展的条件下培养的不同菌株。结果表明，MRM-Profiling 可区分耐药和非耐药菌株的脂质谱。
