title: Violacein as a genetically-controlled, enzymatically amplified and photobleaching-resistant chromophore for optoacoustic bacterial imaging.
abstract: There is growing interest in genetically expressed reporters for in vivo studies of bacterial colonization in the context of infectious disease research, studies of the bacterial microbiome or cancer imaging and treatment. To empower non-invasive high-resolution bacterial tracking with deep tissue penetration, we herein use the genetically controlled biosynthesis of the deep-purple pigment Violacein as a photobleaching-resistant chromophore label for in vivo optoacoustic (photoacoustic) imaging in the near-infrared range. We demonstrate that Violacein-producing bacteria can be imaged with high contrast-to-noise in strongly vascularized xenografted murine tumors and further observe that Violacein shows anti-tumoral activity. Our experiments thus identify Violacein as a robust bacterial label for non-invasive optoacoustic imaging with high potential for basic research and future theranostic applications in bacterial tumor targeting.
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Institute of Developmental Genetics (IDG), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Institute of Developmental Genetics (IDG), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Sigmund
authors.affiliation: Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Josefine
authors.initials: J
authors.lastname: Reber
authors.affiliation: Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Xosé Luís
authors.initials: XL
authors.lastname: Deán-Ben
authors.affiliation: Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Glasl
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Chair for Biological Imaging, Technische Universität München (TUM), Munich, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kneipp
authors.affiliation: Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Héctor
authors.initials: H
authors.lastname: Estrada
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Chair for Biological Imaging, Technische Universität München (TUM), Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Razansky
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Chair for Biological Imaging, Technische Universität München (TUM), Munich, Germany.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Ntziachristos
authors.affiliation: 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany [2] Institute of Developmental Genetics (IDG), Helmholtz Zentrum München, Neuherberg, Germany [3] Department of Nuclear Medicine, Technische Universität München (TUM), Munich, Germany.
authors.forename: Gil G
authors.initials: GG
authors.lastname: Westmeyer
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002861:Chromobacterium / Q000235:genetics; D004926:Escherichia coli / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D007211:Indoles / Q000378:metabolism*; D057054:Molecular Imaging / Q000379:methods*; D061088:Photoacoustic Techniques / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D007211:Indoles; C063155:violacein