title: Towards a detailed understanding of bacterial metabolism--spectroscopic characterization of Staphylococcus epidermidis.
abstract: Bacteria are a major cause of infection. To fight disease and growing resistance, research interest is focused on understanding bacterial metabolism. For a detailed evaluation of the involved mechanisms, a precise knowledge of the molecular composition of the bacteria is required. In this article, various vibrational spectroscopic techniques are applied to comprehensively characterize, on a molecular level, bacteria of the strain Staphylococcus epidermidis, an opportunistic pathogen which has evolved to become a major cause of nosocomial infections. IR absorption spectroscopy reflects the overall chemical composition of the cells, with major focus on the protein vibrations. Smaller sample volumes-down to a single cell-are sufficient to probe the overall chemical composition by means of micro-Raman spectroscopy. The nucleic-acid and aromatic amino-acid moieties are almost exclusively explored by UV resonance Raman spectroscopy. In combination with statistical evaluation methods [hierarchical cluster analysis (HCA), principal component analysis (PCA), linear discriminant analysis (LDA)], the protein and nucleic-acid components that change during the different bacterial growth phases can be identified from the in vivo vibrational spectra. Furthermore, tip-enhanced Raman spectroscopy (TERS) provides insight into the surface structures and follows the dynamics of the polysaccharide and peptide components on the bacterial cells with a spatial resolution below the diffraction limit. This might open new ways for the elucidation of host-bacteria and drug-bacteria interactions.
authors.affiliation: Institut für Physikalische Chemie, Friedrich-Schiller-Universität Jena, Deutschland.
authors.forename: Ute
authors.initials: U
authors.lastname: Neugebauer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schmid
authors.forename: Knut
authors.initials: K
authors.lastname: Baumann
authors.forename: Wilma
authors.initials: W
authors.lastname: Ziebuhr
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kozitskaya
authors.forename: Volker
authors.initials: V
authors.lastname: Deckert
authors.forename: Michael
authors.initials: M
authors.lastname: Schmitt
authors.forename: Jürgen
authors.initials: J
authors.lastname: Popp
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D009696:Nucleic Acids / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013212:Staphylococcus epidermidis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009696:Nucleic Acids