| Affiliation: | (1) Divisions of Systems Toxicology, Microbiology or Biochemical Toxicology, National Center for Toxicological Research, FDA, 3900 NCTR Drive, 2079 Jefferson, AR7, USA;(2) Dephy Technologies, 3552 St. Patrick Street, QC H4E 1A2 Québec, Montreal, Canada;(3) FDA Gulf Coast Seafood Laboratory, 36528 Dauphin Island, AL, USA;(4) FDA Seafood Product Research Center, 98021 Bothell, WA, USA |
| Abstract: | Pyrolysis mass spectrometry was investigated for rapid characterization of food-borne bacterial pathogens. Nine isolates of Vibrio parahaemolyticus and one isolate each of Vibrio fluvialis, Vibrio hollisae, and Vibrio vulnificus were analyzed. Pyrolysis mass spectra, generated via an alternative ionization method, metastable atom bombardment, were subject to principal component-discriminant analysis. The spectral patterns were used to distinguish Vibrio isolates differing in species, serotype and expression of the thermostable direct hemolysin gene. The patterns of similarity and dissimilarity amongst spectra in the Vibrio test set generally reflected those associated with species, serotype or hemolysin-producing genes, though the combined influence of these and other variables in the multi-dimensional data did not produce a simple clustering with respect to any one of these characteristics. These results suggested that with enough examples to model the most common combinations, the method should be able to characterize Vibrio isolates according to their phenotypic characteristics. Pyrolysis-mass spectrometry with metastable atom bombardment and pattern recognition appeared suitable for rapid infraspecific comparison of Vibrio isolates. This integrated analytical, pattern-recognition system should be examined further for potential utility in clinical and public health diagnostic contexts. |
