Rapid Test for Antibiotic Resistances in Urological Sample Material by Surface Enhanced Raman Scattering SERS

在该项目的框架内，将研究表面增强拉曼散射（Sers）与SERS活性胶体的特定原位合成方法相结合，并将其应用于快速抗生素耐药性测试。初步研究表明，该特定方法适合在几分钟内揭示抗生素对单一微生物以及悬浮液中特定微生物的有效性。与目前的方法相反，我们的新方法不是基于拉曼光谱的微小变化来识别不同物质的抗生素作用，而是基于其对SERS活性胶体的产生和聚集的影响。抗微生物物质对跨膜电位的去极化显然阻止了颗粒表面的原位合成或颗粒在那里的聚集。因此，不会发生Sers增强，因此无法检测到死亡生物体的显着SERS信号。这导致了活的和死的生物体的区分的高度显著性，具有活的生物体的高度结构化和特定的信号，并且基本上是死的生物体的基线信号。该方法已成功地测试了几个E。大肠杆菌菌株。在不到一个小时的时间内，多粘菌素B耐药菌株可以从非耐药菌株中区分出来，在不到10分钟的时间内获得了第一个显著的结果。该项目的目的是对新方法在泌尿学中的应用进行简明的测试和验证。将制定适当的样品制备和数据评价战略，重点是在统计可靠性和一到两个小时的短分析时间之间取得平衡。

In the framework of the project, a combination of surface-enhanced Raman scattering (SERS) with a particular in-situ synthesis method for the SERS-active colloids will be investigated and applied as rapid antibiotic resistance tests. Preliminary studies demonstrate that the specific approach is suitable to reveal within few minutes the efficiency of antibiotics against specific microorganisms on a single organism basis as well as in suspension. As opposed to current approaches, our new method identifies the antibiotic effect of different substances not based on minute changes of the Raman spectrum, but on its effect upon generation and aggregation of the SERS-active colloids. The depolarization of the transmembrane potential by the antimicrobial substance apparently prevents in situ synthesis on the particles´ surface, or the aggregation of the particles there. In consequence, no SERS enhancement takes place and thus, no significant SERS-signal of a dead organism can be detected. This leads to a high significance of the distinction of living and dead organisms, with highly structured and specific signals of the living organisms and essentially a baseline signal for dead organisms. The approach was successfully tested for several E. coli strains. In less than one hour, Polymyxin B-resistant strains could be distinguished from non-resistant strains, with the first significant results available in less than 10 min. The aim of the project is a concise test and validation of the novel approach with respect to applications in urology. Suitable sample preparation as well as data evaluation strategies will be developed, a key focus being set on the compromise between statistical reliability and short analysis time of one to two hours.