Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
InfectoGnostics Research Campus Jena, Philosophenweg 7, 07743, Jena, Germany.
Anal Bioanal Chem. 2020 Dec;412(30):8241-8247. doi: 10.1007/s00216-020-02957-2. Epub 2020 Oct 8.
Bacteria can be harmless commensals, beneficial probiotics, or harmful pathogens. Therefore, mankind is challenged to detect and identify bacteria in order to prevent or treat bacterial infections. Examples are identification of species for treatment of infection in clinics and E. coli cell counting for water quality monitoring. Finally, in some instances, the pathogenicity of a species is of interest. The main strategies to investigate pathogenicity are detection of target genes which encode virulence factors. Another strategy could be based on phenotypic identification. Raman spectroscopy is a promising phenotypic method, which offers high sensitivities and specificities for the identification of bacteria species. In this study, we evaluated whether Raman microspectroscopy could be used to determine the pathogenicity of E. coli strains. We used Raman spectra of seven non-pathogenic and seven pathogenic E. coli strains to train a PCA-SVM model. Then, the obtained model was tested by identifying the pathogenicity of three additional E. coli strains. The pathogenicity of these three strains could be correctly identified with a mean sensitivity of 77%, which is suitable for a fast screening of pathogenicity of single bacterial cells. Graphical abstract.
细菌可以是无害的共生菌、有益的益生菌，也可以是有害的病原体。因此，人类面临着检测和识别细菌的挑战，以便预防或治疗细菌感染。例如，在临床中识别物种以治疗感染，以及为了监测水质而对大肠杆菌进行细胞计数。最后，在某些情况下，物种的致病性是人们关注的重点。研究致病性的主要策略是检测编码毒力因子的靶基因。另一种策略可以基于表型鉴定。拉曼光谱是一种很有前途的表型方法，它在鉴定细菌物种方面具有很高的灵敏度和特异性。在这项研究中，我们评估了拉曼显微光谱是否可用于确定大肠杆菌菌株的致病性。我们使用了 7 株非致病性和 7 株致病性大肠杆菌菌株的拉曼光谱来训练 PCA-SVM 模型。然后，通过鉴定另外 3 株大肠杆菌菌株的致病性来测试所获得的模型。这 3 株菌株的致病性可以被正确识别，平均灵敏度为 77%，这适合于快速筛选单个细菌细胞的致病性。
