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Differential survival of Staphylococcal species in macrophages
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  • Christiane Wolz,
  • Janina Bayer,
  • Janna Becker,
  • Xiao Liu,
  • Lisa Gritsch,
  • Ellen Daiber,
  • Natalya Korn,
  • Filipp Oesterhelt,
  • Martin Fraunholz,
  • Alex Weber
Christiane Wolz
Eberhard Karls Universitat Tubingen

Corresponding Author:christiane.wolz@uni-tuebingen.de

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Janina Bayer
Eberhard Karls Universitat Tubingen
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Janna Becker
Eberhard Karls Universitat Tubingen
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Xiao Liu
Eberhard Karls Universitat Tubingen
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Lisa Gritsch
Eberhard Karls Universitat Tubingen
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Ellen Daiber
Eberhard Karls Universitat Tubingen
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Natalya Korn
Eberhard Karls Universitat Tubingen
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Filipp Oesterhelt
Eberhard Karls Universitat Tubingen
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Martin Fraunholz
Julius-Maximilians-Universitat Wurzburg
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Alex Weber
Eberhard Karls Universitat Tubingen
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Abstract

The human pathogen Staphylococcus aureus is considered mainly an extracellular, opportunistic pathogen, yet the bacterium is able to survive within and escape from host cells, including macrophages. An agr/ sae mutant of strain USA300 is unable to escape from human macrophages but can replicate and survive within macrophages. We questioned whether such “„non-toxic“” S. aureus resembles the less pathogenic coagulase-negative Staphylococcal species (CoNS) like S. carnosus, S. lugdunensis, S. capitis, S. warneri or S. pettenkoferi. We show that in contrast to the “„non-toxic“” S. aureus strains, the CoNS species are efficiently killed within 24 h post-infection in the macrophage-like THP-1 cells or in human primary macrophages. Bacterial persistence of “„non-toxic“” S . aureus or CoNS induced IL-1ß release but no cell-death. Mutations in genes coding for katalase, copprer transport or the regulatory system GraRS or SigB did not impact bacterial survival in THP-1 cells. Deletion of the superoxide dismutases sodA and sodM impaired S. aureus survival in human primary macrophages but not in THP-1 cells. However, expression of the S. aureus specific sodM in S. epidermidis was not sufficient to protect this species from being killed in THP-1 cells. Thus, at least in those cells better bacterial survival of S. aureus could not be linked to higher protection from ROS. However, “„non-toxic“” S. aureus was found to be insensitive to pH, whereas S. epidermidis was protected when phagosomal acidification was inhibited. Thus, species differences seem to be linked to different sensitivity to acidification.
28 Apr 2023Submitted to Molecular Microbiology
29 Apr 2023Submission Checks Completed
29 Apr 2023Assigned to Editor
01 May 2023Reviewer(s) Assigned
26 May 2023Review(s) Completed, Editorial Evaluation Pending
05 Jun 2023Editorial Decision: Revise Minor
31 Aug 20231st Revision Received
06 Sep 2023Submission Checks Completed
06 Sep 2023Assigned to Editor
11 Sep 2023Reviewer(s) Assigned
01 Oct 2023Review(s) Completed, Editorial Evaluation Pending
02 Oct 2023Editorial Decision: Accept