Rapid identification of staphylococci by Raman spectroscopy

Abstract

Clinical treatment of the infections caused by various staphylococcal species differ depending on the actual cause of infection. Therefore, it is necessary to develop a fast and reliable method for identification of staphylococci. Raman spectroscopy is an optical method used in multiple scientific fields. Recent studies showed that the method has a potential for use in microbiological research, too. Our work here shows a possibility to identify staphylococci by Raman spectroscopy. We present a method that enables almost 100% successful identification of 16 of the clinically most important staphylococcal species directly from bacterial colonies grown on a Mueller-Hinton agar plate. We obtained characteristic Raman spectra of 277 staphylococcal strains belonging to 16 species from a 24-hour culture of each strain grown on the Mueller-Hinton agar plate using the Raman instrument. The results show that it is possible to distinguish among the tested species using Raman spectroscopy and therefore it has a great potential for use in routine clinical diagnostics.

Surface-Enhanced Raman Scattering Spectroscopy for Label-Free Analysis of P. aeruginosa Quorum Sensing

“…Interpretation of the Raman spectra demands data processing as well as statistical treatments such as multivariate data analysis, which is favored by the high resolution of the SERS spectra. In this framework, chemometric pattern recognition algorithms are widely applied in SERS studies so as to improve the accuracy and reproducibility of the technique facilitating, for instance, the monitoring of different extracellular metabolites in the culture medium (Mishra et al, 2017 ), the discrimination of five types of penicillin G antibiotics despite their high similarities (Clarke et al, 2005 ), or the identification of 16 staphylococcal species (Rebrošová et al, 2017 ). One strategy to avoid the spectral complexity of biological systems consists in enhancing the contribution of the target molecules (i.e., microbial metabolite) employing a laser line with an excitation frequency that is in resonance with an absorption band of the analyte as in SERRS (Bodelón et al, 2016 , 2017 ).…”

“…Based on its high sensitivity and spectral resolution, SERS has been applied successfully to trace analysis, reaching single-molecule detection level under favorable conditions (Nie, 1997 ). Owing to significant key advantages, SERS has emerged in microbiology research for chemical profiling of microbial cells (Liu et al, 2017 ; Lorenz et al, 2017 ), detection and identification of bacteria at different taxonomic levels (Pahlow et al, 2015 ; Rebrošová et al, 2017 ), single cell analysis (Kuku et al, 2017 ), or in vivo diagnostics and multimodal imaging (Henry et al, 2016 ; Cialla-May et al, 2017 ; Krafft et al, 2017 ).…”

Confocal Raman microscopy to identify bacteria in oral subgingival biofilm models

“…Previously, CRM has been successful in the spatial resolution of biomedical environments like tissue samples or bacterial cells [14][15][16][17][18]. However, the acquired signals from these biomedical components are highly complex [19][20][21].…”

Raman microspectroscopy differentiates perinatal pathogens on ex vivo infected human fetal membrane tissues

“…Raman spectroscopy (RS) is an inelastic light scattering technique that provides a biochemical “fingerprint” with sensitivity to features such as nucleic acids, carbohydrates, lipids and proteins. Raman microspectroscopy (RμS), which provides higher spectral resolution, has been used to characterize bacteria and provide discrimination at the genus and species levels in vitro and identify bacteria directly from clinical samples culture‐free . This technique could provide opportunities to identify GBS or other bacteria as a rapid diagnostic test, minimizing sample preparation and streamlining diagnostic information.…”