title: Spatial Mapping of Pyocyanin in Pseudomonas Aeruginosa Bacterial Communities Using Surface Enhanced Raman Scattering.
abstract: Surface enhanced Raman spectroscopy (SERS) imaging was used in conjunction with principal component analysis (PCA) for the in situ spatiotemporal mapping of the virulence factor pyocyanin in communities of the pathogenic bacterium Pseudomonas aeruginosa. The combination of SERS imaging and PCA analysis provides a robust method for the characterization of heterogeneous biological systems while circumventing issues associated with interference from sample autofluorescence and low reproducibility of SERS signals. The production of pyocyanin is found to depend both on the growth carbon source and on the specific strain of P. aeruginosa studied. A cystic fibrosis lung isolate strain of P. aeruginosa synthesizes and secretes pyocyanin when grown with glucose and glutamate, while the laboratory strain exhibits detectable production of pyocyanin only when grown with glutamate as the source of carbon. Pyocyanin production in the laboratory strain grown with glucose was below the limit of detection of SERS. In addition, the combination of SERS imaging and PCA can elucidate subtle differences in the molecular composition of biofilms. PCA loading plots from the clinical isolate exhibit features corresponding to vibrational bands of carbohydrates, which represent the mucoid biofilm matrix specific to that isolate, features that are not seen in the PCA loading plots of the laboratory strain.
authors.affiliation: 1 Department of Chemical and Biomolecular Engineering, University of Notre Dame, USA.
authors.forename: Sneha
authors.initials: S
authors.lastname: Polisetti
authors.affiliation: 2 Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, USA.
authors.forename: Nameera F
authors.initials: NF
authors.lastname: Baig
authors.affiliation: 3 Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, USA.|4 Eck Institute for Global Health, University of Notre Dame, USA.
authors.forename: Nydia
authors.initials: N
authors.lastname: Morales-Soto
authors.affiliation: 3 Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, USA.|4 Eck Institute for Global Health, University of Notre Dame, USA.|5 Department of Biological Sciences, University of Notre Dame, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Shrout
authors.affiliation: 1 Department of Chemical and Biomolecular Engineering, University of Notre Dame, USA.|2 Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Bohn
mesh_terms: D018441:Biofilms; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000382:microbiology; D006801:Humans; D025341:Principal Component Analysis; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000145:classification; D011710:Pyocyanine / Q000032:analysis* / Q000737:chemistry*; D015203:Reproducibility of Results; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D011710:Pyocyanine
keywords: PCA; Pseudomonas aeruginosa; SERS; biofilms; principal component analysis; pyocyanin; surface enhanced Raman spectroscopy