A micro-Raman and chemometric study of urinary tract infection-causing bacterial pathogens in mixed cultures
Detection of urinary tract infection (UTI)-causing bacteria uses conventional time-consuming microbiological techniques. The current need is to use a fast and reliable method of bacterial identification. In order to unambiguously distinguish the UTI-causing five bacterial species used in the current study, micro-Raman spectra were obtained from a home-assembled micro-Raman system and analyzed by multivariate statistical techniques such as principal component analysis (PCA), partial least square-discriminate analysis (PLS-DA), and support vector machine (SVM). Also, the micro-Raman spectra recorded from samples containing two and three bacterial species were tested and validated against the aforementioned calibration models using PLS-DA and SVM. The prediction accuracies of up to 73 and 89% were achieved with PLS-DA and SVM, respectively. Taken together, the present study depicts the capturing of unique micro-Raman spectral features manifesting from the biochemical content of each bacterium. Also, micro-Raman spectroscopy combined with multivariate data analysis can therefore be a reliable and faster technique for the diagnosis of UTI-causing bacteria.
KeywordsMicro-Raman spectroscopy UTI-causing bacteria Multivariate classification PCA PLS-DA SVM
Principal component analysis
Partial least square-discriminate analysis
Support vector machine
Urinary tract infection
The authors are thankful to the Department of Biotechnology, Govt. of India, and one of the authors is thankful to Vision Group of Science and Technology (VGST), Govt. of Karnataka for establishing the Centre for Excellence in Biophotonics and Dr. TMA Pai Endowment Chair fellowship, Manipal Academy of Higher Education, Manipal.
This study was supported by the Department of Biotechnology, Govt. of India for the micro-Raman facility through the sanctioned projects (BT/PR6413/MED/14/80/2005 and BT/PR3159/BRB/10/960/2011), Vision Group of Science and Technology (VGST), Govt. of Karnataka, and Dr. TMA Pai Endowment Chair fellowship, Manipal Academy of Higher Education, Manipal.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Research involving human participants and/or animals
There was no direct involvement of human participants. All individual participants had given informed written consent for the present study. The experiments were carried in accordance with approved ethical guidelines of the Institutional Ethics Committee, Kasturba Medical College and Kasturba Hospital, Manipal.
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