Reversible changes in fluorescence of bacterial endospores found in aerosols due to hydration/drying

Abstract In this study we show that the room temperature multiwavelength autofluorescence signature of wet Bacillus endospores is considerably different from that of the dry endospores. The fluorescence is measured with excitation wavelengths of 300–500 nm with 50 nm steps. Small differences are observed between the dry and the re-dried spores. The fluorescence spectra support the model of reversible water migration between inner spore compartments and the environment. Characteristic information is extracted from spectral fluorescence excitation–emission contours for these spores by applying the dimensional reduction of data techniques known as principal component analysis. Aerosol detection and identification techniques relying on fluorescence must take into account the hydration state of the spores and recognize the ability of the spores to rapidly change their state of hydration.

[1]  A. Westphal,et al.  Kinetics of size changes of individual Bacillus thuringiensis spores in response to changes in relative humidity , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[2]  T. C. Beaman,et al.  Dehydration partitioned within core protoplast accounts for heat resistance of bacterial spores , 1984 .

[3]  R. Doi.  Sporulation and Germination , 1989 .

[4]  B. Marshall,et al.  (Symposium on Bacterial Spores : Paper IX). Biophysical Analysis of the Spore , 1970 .

[5]  Jerri Tribble,et al.  Bacteria identification of otitis media with fluorescence spectroscopy , 1994, Lasers in surgery and medicine.

[6]  P. Lillford,et al.  Effects of hydration on molecular mobility in phase-bright Bacillus subtilis spores. , 2000, Microbiology.

[7]  B. V. Bronk,et al.  Effects of Autoclaving on Bacterial Endospores Studied by Fourier Transform Infrared Microspectroscopy , 2004, Applied spectroscopy.

[8]  G. Kateman,et al.  Three-component curve resolution in liquid chromatography with multiwavelength diode array detection , 1985 .

[9]  P. Gerhardt,et al.  PERMEABILITY OF BACTERIAL SPORES I , 1961, Journal of bacteriology.

[10]  D. Naumann,et al.  Classification and identification of bacteria by Fourier-transform infrared spectroscopy. , 1991, Journal of general microbiology.

[11]  L. Reinisch,et al.  Noninvasive Fluorescent Identification of Bacteria Causing Acute Otitis Media in a Chinchilla Model , 2000, The Laryngoscope.

[12]  Lou Reinisch,et al.  Identification of Bacillus Spores Using Clustering of Principal Components of Fluorescence Data , 2005 .

[13]  J. Lakowicz.  Principles of fluorescence spectroscopy , 1983 .

[14]  F. Lytle,et al.  Identification of bacterial pathogens by laser excited fluorescence , 1985 .

[15]  P. Gerhardt,et al.  Permeability of bacterial spores. IV. Water content, uptake, and distribution. , 1962, Journal of bacteriology.

[16]  T. C. Beaman,et al.  Bacterial spore heat resistance correlated with water content, wet density, and protoplast/sporoplast volume ratio , 1982, Journal of bacteriology.

[17]  L. Reinisch,et al.  Changes in the luminescence between dried and wet bacillus spores. , 2004, Applied optics.

[18]  Renato Amaro Zângaro,et al.  Rapid Identification of Bacterial Species by Fluorescence Spectroscopy and Classification Through Principal Components Analysis , 2003, Journal of Fluorescence.

[19]  L Reinisch,et al.  Noninvasive optical diagnosis of bacteria causing otitis media , 1994, The Laryngoscope.

[20]  Burt V. Bronk,et al.  Variability of Steady-State Bacterial Fluorescence with Respect to Growth Conditions , 1993 .

[21]  J. C. Lewis,et al.  Water Permeability of Bacterial Spores and the Concept of a Contractile Cortex , 1960, Science.

[22]  J. Thompson,et al.  Sorption of Water Vapour and Nitrogen Gas by Bacterial Spores , 1967, Nature.

[23]  Jack Saltiel,et al.  Three-component self-modeling technique applied to luminescence spectra , 1987 .