title: Sensitive and specific discrimination of pathogenic and nonpathogenic Escherichia coli using Raman spectroscopy-a comparison of two multivariate analysis techniques.
abstract: The determination of bacterial identity at the strain level is still a complex and time-consuming endeavor. In this study, visible wavelength spontaneous Raman spectroscopy has been used for the discrimination of four closely related Escherichia coli strains: pathogenic enterohemorrhagic E. coli O157:H7 and non-pathogenic E. coli C, E. coli Hfr K-12, and E. coli HF4714. Raman spectra from 600 to 2000 cm(-1) were analyzed with two multivariate chemometric techniques, principal component-discriminant function analysis and partial least squares-discriminant analysis, to determine optimal parameters for the discrimination of pathogenic E. coli from the non-pathogenic strains. Spectral preprocessing techniques such as smoothing with windows of various sizes and differentiation were investigated. The sensitivity and specificity of both techniques was in excess of 95%, determined by external testing of the chemometric models. This study suggests that spontaneous Raman spectroscopy with visible wavelength excitation is potentially useful for the rapid identification and classification of clinically-relevant bacteria at the strain level.
authors.affiliation: Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, USA ; Now with Department of Basic Science, Al-Huson University College, Al-Balqa Applied University, Irbid, Jordan.
authors.forename: Khozima
authors.initials: K
authors.lastname: Hamasha
authors.forename: Qassem I
authors.initials: QI
authors.lastname: Mohaidat
authors.forename: Russell A
authors.initials: RA
authors.lastname: Putnam
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Woodman
authors.forename: Sunil
authors.initials: S
authors.lastname: Palchaudhuri
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rehse
keywords: (170.0170) Medical optics and biotechnology; (170.1420) Biology; (170.1530) Cell analysis; (170.1580) Chemometrics; (170.5660) Raman spectroscopy; (300.6450) Spectroscopy, Raman