Biochemical characterization of pathogenic bacterial species using Raman spectroscopy and discrimination model based on selected spectral features

Author(s)

de Siqueira e Oliveira, Fernanda SantAna ^[1] ; da Silva, Adriano Moraes ^[1] ; Tavares Pacheco, Marcos Tadeu ^[2] ; Giana, Hector Enrique ^[3] ; Silveira Jr, Landulfo

Affiliation

^[1] Univ Paulista UNIP, Inst Ciencias Saude, Rod Pres Dutra, Km 157, BR-12240420 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Anhembi Monunbi UAM, Ctr Innovat Technol & Educ CITE, Parque Tecnol Sao Jose dos Campos, BR-12247016 Sao Jose Dos Campos, SP - Brazil

^[3] Lab Oswaldo Cruz, Pca Candida Maria Cesar Sawaya Giana 128, BR-12243003 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 36, n. 2 JUN 2020.
• Web of Science Citations: 0

Abstract

This study aimed to evaluate the differences in the Raman spectra of nine clinical species of bacteria isolated from infections (three Gram-positive and six Gram-negative species), correlating the spectra with the chemical composition of each species and to develop a classification model through discriminant analysis to categorize each bacterial strain using the peaks with the most significant differences. Bacteria were cultured in Mueller Hinton agar and a sample of biomass was harvested and placed in an aluminum sample holder. A total of 475 spectra from 115 different strains were obtained through a dispersive Raman spectrometer (830 nm) with exposure time of 50 s. The intensities of the peaks were evaluated by one-way analysis of variance (ANOVA) and the peaks with significant differences were related to the differences in the biochemical composition of the strains. Discriminant analysis based on quadratic distance applied to the peaks with the most significant differences and partial least squares applied to the whole spectrum showed 89.5% and 90.1% of global accuracy, respectively, for classification of the spectra in all the groups. Raman spectroscopy could be a promising technique to identify spectral differences related to the biochemical content of pathogenic microorganisms and to provide a faster diagnosis of infectious diseases. (AU)

• FAPESP's process: 09/01788-5 - Dispersive Raman spectroscopy using optical fibers "Raman probe" applied to the diagnosis of neoplasia in the skin and prostate
• Grantee: Landulfo Silveira Junior
• Support Opportunities: Regular Research Grants