Towards the clinical application of laser-induced breakdown spectroscopy for rapid pathogen diagnosis: the effect of mixed cultures and sample dilution on bacterial identification

Abstract

Rehse, Steven J.; Mohaidat, Q.I.; and Palchaudhuri, S.. (2010). Towards the clinical application of laser-induced breakdown spectroscopy for rapid pathogen diagnosis: The effect of mixed cultures and sample dilution on bacterial identification. Laser-induced breakdown spectroscopy has been utilized to classify and identify bacterial specimens on the basis of their atomic composition. We have characterized the effect that the presence of a second bacterial species in the ablated specimen had on the identification of the majority species. Specimens with a reduced number of bacterial cells (approximately 2500) were identified with 100% accuracy when compared to undiluted specimens. In addition, a linear dependence of the total spectral power as a function of cell number was determined. Lastly, a high selectivity was obtained for a LIBS-based analysis of nine separate bacterial strains from four genera.

Detection and Classification of Live and DeadEscherichia coliby Laser-Induced Breakdown Spectroscopy

“…Thus, the information on ratios of ions and lifeimportant elements can be used to identify whether the bacteria are dead or alive and the method of treatments. Elemental composition changes in P, C, Mg, Ca, and Na were previously used to discriminate between species of bacteria, so in an environmental setting our approach would be best applied to a sample where it is observed while being challenged by sonication or heat in order for the elemental abundances to reflect a change in life state of the cells and not the species composition (Rehse et al, 2010). Nanosecond laser ablation causes splashing of the bacterial cells, which complicates tremendously the analysis (see Figs.…”

A comparison of multivariate analysis techniques and variable selection strategies in a laser-induced breakdown spectroscopy bacterial classification

“…[5,19] Briefly, 10 ns 1064 nm infrared laser pulses were used to ablate the bacterial specimens mounted on a 0.7% nutrient-free agar substrate in an argon environment. LIBS emission was collected 2 s after the ablation pulse, dispersed in an Échelle spectrograph, and the spectra were recorded by an intensified charge-coupled device (ESA3000, LLA Instruments, GmbH).…”

“…[1][2][3][4] Over the last five years we and others have demonstrated a sensitive and specific identification of live bacterial biospecimens utilizing a discriminant function analysis (DFA) to classify LIBS spectra. [5][6][7][8] The intensities of strong specific elemental atomic emission lines normalized by the total observed spectral power have been utilized as independent variables in this multivariate analysis. [9] The selection of specific spectral lines to serve as independent variables in the multivariate analysis is known as variable down-selection.…”

Laser-Induced Breakdown Spectroscopy: Fundamentals, Applications, and Challenges

“…In the same way, cancer detection is possible with LIBS and it can provide a surgical device which can detect and destroy tumor cells at the same time [85]. In addition, classification of pathogenic bacteria or virus is possible too [86,87].…”