title: Label-free imaging and spectroscopic analysis of intracellular bacterial infections.
abstract: Staphylococcus aureus is one of the most frequent human pathogens that can also act as a facultative intracellular pathogen causing infections that are extremely difficult to treat. Only little is known about the pathogen's intracellular adaptation strategies to escape the host's response. Here, we present an advanced Raman-based imaging approach providing high quality false-color images to specifically identify intracellular S. aureus and to localize them exactly in three dimensions within endothelial cells. At the same time unprecedented insights into the metabolic characteristics of the pathogen are provided in a label-free and nondestructive manner. The spectral information reveals that the intracellular bacteria are in the exponential growth phase with a reduced replication rate and biochemically different from extracellular bacteria proving their adaptation to the host's conditions. This powerful biophotonic analysis tool paves the way for further mechanistic studies of difficult-to-investigate infection processes.
authors.affiliation: Center for Sepsis Control and Care, Jena University Hospital , Erlanger Allee 101, D-07747 Jena, Thuringia, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Große
authors.forename: Norbert
authors.initials: N
authors.lastname: Bergner
authors.forename: Jan
authors.initials: J
authors.lastname: Dellith
authors.forename: Regine
authors.initials: R
authors.lastname: Heller
authors.forename: Michael
authors.initials: M
authors.lastname: Bauer
authors.forename: Alexander
authors.initials: A
authors.lastname: Mellmann
authors.forename: Jürgen
authors.initials: J
authors.lastname: Popp
authors.forename: Ute
authors.initials: U
authors.lastname: Neugebauer
mesh_terms: D002460:Cell Line; D042783:Endothelial Cells / Q000382:microbiology*; D006801:Humans; D013059:Spectrum Analysis, Raman / Q000379:methods; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000166:cytology / Q000254:growth & development / Q000302:isolation & purification*