title: Staphylococcus aureus Exploits a Non-ribosomal Cyclic Dipeptide to Modulate Survival within Epithelial Cells and Phagocytes.
abstract: Community-acquired (CA) Staphylococcus aureus cause various diseases even in healthy individuals. Enhanced virulence of CA-strains is partly attributed to increased production of toxins such as phenol-soluble modulins (PSM). The pathogen is internalized efficiently by mammalian host cells and intracellular S. aureus has recently been shown to contribute to disease. Upon internalization, cytotoxic S. aureus strains can disrupt phagosomal membranes and kill host cells in a PSM-dependent manner. However, PSM are not sufficient for these processes. Here we screened for factors required for intracellular S. aureus virulence. We infected escape reporter host cells with strains from an established transposon mutant library and detected phagosomal escape rates using automated microscopy. We thereby, among other factors, identified a non-ribosomal peptide synthetase (NRPS) to be required for efficient phagosomal escape and intracellular survival of S. aureus as well as induction of host cell death. By genetic complementation as well as supplementation with the synthetic NRPS product, the cyclic dipeptide phevalin, wild-type phenotypes were restored. We further demonstrate that the NRPS is contributing to virulence in a mouse pneumonia model. Together, our data illustrate a hitherto unrecognized function of the S. aureus NRPS and its dipeptide product during S. aureus infection.
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Blättner
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany.
authors.forename: Sudip
authors.initials: S
authors.lastname: Das
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Paprotka
authors.affiliation: Core Unit Functional Genomics, University of Würzburg, Würzburg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Eilers
authors.affiliation: Biocenter, Chair of Pharmaceutical Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Krischke
authors.affiliation: Department of Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), University Tübingen, Tübingen, Germany.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Kretschmer
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, Würzburg, Germany.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Remmele
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, Würzburg, Germany.|Institute of Human Genetics, University of Würzburg, Würzburg, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Dittrich
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Müller
authors.affiliation: Core Unit Functional Genomics, University of Würzburg, Würzburg, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Schuelein-Voelk
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hertlein
authors.affiliation: Biocenter, Chair of Pharmaceutical Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Mueller
authors.affiliation: Max Planck Genome Centre, Cologne, Germany.
authors.forename: Bruno
authors.initials: B
authors.lastname: Huettel
authors.affiliation: Max Planck Genome Centre, Cologne, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
authors.affiliation: Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Knut
authors.initials: K
authors.lastname: Ohlsen
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rudel
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany.
authors.forename: Martin J
authors.identifier: 0000-0002-4581-6244
authors.initials: MJ
authors.lastname: Fraunholz
mesh_terms: D000818:Animals; D004151:Dipeptides / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D050296:Microbial Viability; D046908:Peptide Biosynthesis, Nucleic Acid-Independent / Q000502:physiology*; D010456:Peptides, Cyclic / Q000096:biosynthesis*; D010586:Phagocytes / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D010456:Peptides, Cyclic