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M. A. AL-HOLY, Clinical Nutrition and Dietetics, Hashemite Univ., Zarqa, 13115, Jordan, B. Rasco, Food Science and Human Nutrition, Washington State Univ., Dept. of Food Science and Human Nutrition, Box 646376, Pullman, WA 99164-6373, and M. Lin, Dept. of Food Science & Human Nutrition, Washington State Univ., PO Box 646376, Pullman, WA 99164-6376. The occurrence of food-borne illness caused by pathogenic microorganism is unavoidable despite rigorous hygienic practices adopted in food preparation areas. A rapid, simple, low-cost detection and identification method of microbes in food is still unavailable despite years of effort addressing this issue. Recently, there has been much effort invested in developing rapid identification methods for disease-causing microorganisms, such as ATP bioluminescence, ELISA and immunolabeled nano-colloids, and microarray chips and PCR. However, these approaches are time-consuming, labor intensive, and usually require highly trained individuals, which makes testing of a large number of samples either difficult or cost prohibitive. FT-IR spectroscopy along with multivariate analysis can easily distinguish biochemical compounds and may serve as a practical alternative to the presently used techniques. The goal of this study was to determine whether FT-IR: (4000-600 cm-1) could be used to discriminate between different genera, species, and strains of important food-borne pathogens and related non-pathogenic species. Fourier transform infrared spectroscopy (FT-IR: 4000-600 cm-1) was used to classify and identify various food-borne pathogens at the genus and strain level including: Bacillus cereus, Salmonella enterica, Escherichia coli, and Listeria spp. Spectra of Bacterial suspensions (ca. 109 CFU/ml in 0.9% NaCl) on Anodisc (aluminum oxide) filters were tested. Unique FT-IR vibrational overtone and combinations bands from mid-IR active components in bacterial cells were presenting the “fingerprint region” at wavenumbers between 1500 and 800 cm-1. Clear segregations between different genera, species and strains of bacteria were observed. This study is further evidence that FT-IR can detect differences in bacterial cell constituents. This study shows that FT-IR is a promising technique for the identification of food-borne pathogens and could be useful to provide a rapid assessment of pathogen contamination, which is critical for monitoring food safety and regulatory testing.
Session 33, Food Microbiology: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |