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Journal of Pathogens
Volume 2013 (2013), Article ID 898106, 11 pages
Research Article

Proof of Principle for a Real-Time Pathogen Isolation Media Diagnostic: The Use of Laser-Induced Breakdown Spectroscopy to Discriminate Bacterial Pathogens and Antimicrobial-Resistant Staphylococcus aureus Strains Grown on Blood Agar

1Applied Research Associates, Inc., 4300 San Mateo Boulevard, NE Suite A-220, Albuquerque, NM 87110, USA
2Microbiology Group, Department of Biology, Molecular Biology Program, New Mexico State University, Las Cruces, NM 88003, USA
3Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA

Received 27 December 2012; Revised 29 April 2013; Accepted 16 May 2013

Academic Editor: Cormac G. M. Gahan

Copyright © 2013 Rosalie A. Multari et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Laser-Induced Breakdown Spectroscopy (LIBS) is a rapid, in situ, diagnostic technique in which light emissions from a laser plasma formed on the sample are used for analysis allowing automated analysis results to be available in seconds to minutes. This speed of analysis coupled with little or no sample preparation makes LIBS an attractive detection tool. In this study, it is demonstrated that LIBS can be utilized to discriminate both the bacterial species and strains of bacterial colonies grown on blood agar. A discrimination algorithm was created based on multivariate regression analysis of spectral data. The algorithm was deployed on a simulated LIBS instrument system to demonstrate discrimination capability using 6 species. Genetically altered Staphylococcus aureus strains grown on BA, including isogenic sets that differed only by the acquisition of mutations that increase fusidic acid or vancomycin resistance, were also discriminated. The algorithm successfully identified all thirteen cultures used in this study in a time period of 2 minutes. This work provides proof of principle for a LIBS instrumentation system that could be developed for the rapid discrimination of bacterial species and strains demonstrating relatively minor genomic alterations using data collected directly from pathogen isolation media.