Multiplex identification of bacteria in bacterial mixtures with surface-enhanced Raman scattering

Surface-enhanced Raman scattering (SERS) is a technique capable of identifying each component in a mixture because of its intrinsically narrow spectral bands. In a clinical setting, the identification of bacteria from its initial culture by collecting the colonies on the culture plate significantly decreases the analysis time and the cost. The identification of bacteria from their mixtures is attempted using SERS. A simple mixing procedure of bacterial samples and concentrated colloidal suspension is proven to be mostly satisfactory for the generation of the reproducible SERS spectra that can be used for bacterial identification. The mixture of three different but related bacterial species Shigella sonnei, Proteus vulgaris, and Erwinia amylovara and three Escherichia coli strains (BFK13, BHK7, DH5 alpha) are used as model systems to test the feasibility of the approach. The results indicate that it is possible to identify the composition of a bacterial mixture. This approach can easily be utilized for the bacteria originating from the same source with similar growth profiles. Copyright (C) 2009 John Wiley & Sons, Ltd.