Rapid Detection of Bacteria and Other Microorganisms: A Basic Study in the Application of Resonance Raman and Time-Resolved Fluorescence Spectroscopies

摘要

Resonance Raman Spectra have been obtained for a variety of chromobacteria using low power 488 nm excitation. Spectra are simple, of high quality, and useful for identification purposes at the species level. Raman microprobe studies show conclusively that spectra can be obtained from single cells in pure cultures or in mixed cultures without need for separation. Extensions of the study have been made to representative colorless gram-negative and gram-positive bacteria. Spora other than bacteria have been studied as well. Pollen, mold spores, bacterial spores, algae and viruses all give spectra but only viruses and bacterial spores appear to give intense UV Resonance Raman spectra. The primary fluorescence of bacteria has been studied in detail to determined its potential in rapid detection. We have determined fluorescence for S. epidermidis, P. fluorescens, E. cloacae, E. coli and B. subtilis. Fluorescence contributions have been assigned in part to tryptophan, pteridines, related flavins and pyridine coenzymes.