Rapid Detection and Identification of Pseudomonas aeruginosa and Escherichia coli as Pure and Mixed Cultures in Bottled Drinking Water Using Fourier Transform Infrared Spectroscopy and Multivariate Analysis

Abstract

Fourier transform infrared (FT-IR) spectroscopy and multivariate analysis were used to identify Pseudomonas aeruginosa and Escherichia coli ATCC 25922 inoculated into bottled drinking water. Three inoculation treatments were examined: (i) E. coli ATCC 25922 (N = 3), (ii) P. aeruginosa (N = 3), and (iii) a 1:1 (v:v) mixed culture of both P. aeruginosa and E. coli ATCC 25922 (N = 3). The control treatment was noninoculated drinking water (N = 3). Second derivative transformation and loadings plots over the range of 1800-900 cm(-1) indicate variations in the following bacterial constituents: amide I band ca. 1650 cm(-1), amide II band ca. 1540 cm(-1), phosphodiester backbone of nucleic acids ca. 1242 and 1080 cm(-1), and polysaccharide compounds ca. 1050-950 cm(-1). Cells with the different treatments were clearly segregated from a mean centered principal component analysis. By using soft independent modeling of class analogy analysis, spectra from a given treatment could be correctly classified 83-88% of the time. These results suggest that FT-IR spectroscopy can determine whether a pure culture is present, in addition to confirming that this method can discriminate between closely related bacteria based on differences in biochemical and phenotypic characteristics that can be detected in this spectral region.

Mode of Action and Synergy of Ceftazidime and Baicalein against <i>Streptococcus pyogenes</i>

“…The second loading of the treated and control groups indicated that the obvious regions at 3000-2800 cm -1 (~2963, ~2921, ~2875, ~2852 cm -1 ) could be attributed to the stretching modes of CH 2 and CH 3 in the fatty acids located on the various membrane amphiphiles and ester bands, respectively (Figure 4d) [25,26]. The treated cells exhibited a peak area and intensity at ~2921 and ~2852 cm -1 , respectively, of ceftazidime > control > ceftazidime plus baicalein (Figure 4d) [23,27].…”

“…The biomolecule fingerprint clusters for the control and the ceftazidime alone or in combination with baicalein groups were clearly differentiated [23,27].…”

New Spectral Applications of the Fourier Transforms in Medicine, Biological and Biomedical Fields

“…FTIR methods combined with various chemometric analyses procedures [28][29][30] can be applied to the ield of medical applications, pharmaceutical industry, and food microbiology, comprising the detection of bacteria from culture and food, discrimination between various microbial species and strains, classiication of a diversity of microorganisms at genus, species, and subspecies levels, bacteria viability analysis, characterization growth-dependent phenomena and cell-drug interactions, investigation in situ intracellular components or structures such as inclusion bodies (IBs), storage materials, or endospores [31]. Because in biological and in medical ield, protein aggregation represents an important issue encountered in the expression of recombinant proteins in bacterial cells in the form of IBs and in some diseases, the monitoring in vivo of the kinetics of protein aggregation in Escherichia coli within intact cells using the FTIR spectroscopy methods constitutes a fast and a facile technique used to acquire structural information on proteins within IBs [32].…”

Identification and discrimination of bacteria using Fourier transform infrared spectroscopy

“…4) [29,30]. The spectral analysis of vibration modes in this range included m s CH 2 (2863-2843 cm À1 ), m s CH 3 (2882-2862 cm À1 ), m as CH 2 (2936-2916 cm À1 ), and m as CH 3 (2972-2952 cm À1 ) [10,23,24,29].…”