title: Following drug uptake and reactions inside Escherichia coli cells by Raman microspectroscopy.
abstract: Raman microspectroscopy combined with Raman difference spectroscopy reveals the details of chemical reactions within bacterial cells. The method provides direct quantitative data on penetration of druglike molecules into Escherichia coli cells in situ along with the details of drug-target reactions. With this label-free technique, clavulanic acid and tazobactam can be observed as they penetrate into E. coli cells and subsequently inhibit β-lactamase enzymes produced within these cells. When E. coli cells contain a β-lactamase that forms a stable complex with an inhibitor, the Raman signature of the known enamine acyl-enzyme complex is detected. From Raman intensities it is facile to measure semiquantitatively the number of clavulanic acid molecules taken up by the lactamase-free cells during growth.
authors.affiliation: Departments of Chemistry, §Molecular Biology and Microbiology, ∥Pharmacology, ⊥Medicine, and #Biochemistry, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Hossein
authors.initials: H
authors.lastname: Heidari Torkabadi
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Bethel
authors.forename: Krisztina M
authors.initials: KM
authors.lastname: Papp-Wallace
authors.forename: Piet A J
authors.initials: PA
authors.lastname: de Boer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bonomo
authors.forename: Paul R
authors.initials: PR
authors.lastname: Carey
mesh_terms: D019818:Clavulanic Acid / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D005612:Freeze Drying; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D013059:Spectrum Analysis, Raman / Q000379:methods; D000078142:Tazobactam; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D065093:beta-Lactamase Inhibitors; D019818:Clavulanic Acid; D010397:Penicillanic Acid; C491478:beta-lactamase KPC-2; C054882:beta-lactamase PIT-2; D001618:beta-Lactamases; D000078142:Tazobactam