Fourier transform infrared and Raman microspectroscopy are currently being developed as new methods for the rapid identification of clinically relevant microorganisms. These methods involve measuring spectra from microcolonies which have been cultured for as little as 6 h, followed by the nonsubjective identification of microorganisms through the use of multivariate statistical analyses. To examine the biological heterogeneity of microorganism growth which is reflected in the spectra, measurements were acquired from various positions within (micro)colonies cultured for 6, 12, and 24 h. The studies reveal that there is little spectral variance in 6-h microcolonies. In contrast, the 12- and 24-h cultures exhibited a significant amount of heterogeneity. Hierarchical cluster analysis of the spectra from the various positions and depths reveals the presence of different layers in the colonies. Further analysis indicates that spectra acquired from the surface of the colonies exhibit higher levels of glycogen than do the deeper layers of the colony. Additionally, the spectra from the deeper layers present with higher RNA levels than the surface layers. Therefore, the 6-h colonies with their limited heterogeneity are more suitable for inclusion in a spectral database to be used for classification purposes. These results also demonstrate that vibrational spectroscopic techniques can be useful tools for studying the nature of colony development and biofilm formation.
Investigating microbial (micro)colony heterogeneity by vibrational spectroscopy / L.P. Choo-Smith, K. Maquelin, T. van Vreeswijk, H.A. Bruining, G.J. Puppels, N.A. Ngo Thi, C. Kirschner, D. Naumann, D. Ami, A.M. Villa, F. Orsini, S.M. Doglia, H. Lamfarraj, G.D. Sockalingum, M. Manfait, P. Allouch, H.P. Endtz. - In: APPLIED AND ENVIRONMENTAL MICROBIOLOGY. - ISSN 0099-2240. - 67:4(2001 Apr), pp. 1461-1469.
|Titolo:||Investigating microbial (micro)colony heterogeneity by vibrational spectroscopy|
|Parole Chiave:||candida albicans ; culture media ; Escherichia coli ; humans ; microbiological techniques ; spectroscopy, Fourier transform infrared ; spectrum analysis, Raman ; staphylococcus aureus|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin)
Settore FIS/01 - Fisica Sperimentale
|Data di pubblicazione:||apr-2001|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1128/AEM.67.4.1461-1469.2001|
|Appare nelle tipologie:||01 - Articolo su periodico|