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United States Department of Agriculture

Agricultural Research Service


item Harhay, Gregory
item Siragusa, Gregory

Submitted to: Journal of Rapid Methods and Automation in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: An optical-based, rapid method for identifying bacteria was developed that has the potential to rapidly and selectively identify and quantify bacteria in food products. The method was developed to help food processors, including meat packers, potentially identify bacteria in a short time, perhaps as quickly as seconds to minutes. Also, this technique could result in a means to quantify the number of specific bacteria in a sample. It is based on the specific manner in which different bacteria change the direction and color of laser light that is focused on the sample containing bacteria. The scattered light from a pure culture of bacteria yields a characteristic signature of the bacteria. Once a sample is taken and run through the instrument, a computer database of bacterial signatures is checked for any known bacterial signatures similar to the test sample bacteria. If the database recognizes a signature it responds by telling the operator the identity and quantity of the detected bacteria.

Technical Abstract: The rapid identification and quantification of potentially pathogenic foodborne bacteria is a national research priority. We present a new spectrochemical method that has the potential to rapidly and selectively identify and quantify bacteria in food products. This method utilizes hydrogen-deuterium exchange to resolve the spectral fingerprints of individual components in the overlapped regions of the ultraviolet resonance Raman spectra of food samples. We illustrate this concept with hydrogen-deuterium induced changes in the spectra of bacteria and carcass wash samples. This combination of ultraviolet resonance Raman spectroscopy and hydrogen-deuterium exchange has the potential of providing the identities and quantities of bacteria in complex mixtures within seconds to minutes.

Last Modified: 06/25/2017
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