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The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids.

ABSTRACT: The Staphylococcus aureus type VII secretion system (T7SS) exports several proteins that are pivotal for bacterial virulence. The mechanisms underlying T7SS-mediated staphylococcal survival during infection nevertheless remain unclear. Here we report that S. aureus lacking T7SS components are more susceptible to host-derived antimicrobial fatty acids. Unsaturated fatty acids such as linoleic acid (LA) elicited an increased inhibition of S. aureus mutants lacking T7SS effectors EsxC, EsxA and EsxB, or the membrane-bound ATPase EssC, compared to the wild-type (WT). T7SS mutants generated in different S. aureus strain backgrounds also displayed an increased sensitivity to LA. Analysis of bacterial membrane lipid profiles revealed that the esxC mutant was less able to incorporate LA into its membrane phospholipids. Although the ability to bind labelled LA did not differ between the WT and mutant strains, LA induced more cell membrane damage in the T7SS mutants compared to the WT. Furthermore, proteomic analyses of WT and mutant cell fractions revealed that, in addition to compromising membranes, T7SS defects induce oxidative stress and hamper their response to LA challenge. Thus, our findings indicate that T7SS contribute to maintaining S. aureus membrane integrity and homeostasis when bacteria encounter antimicrobial fatty acids.

SUBMITTER: Kengmo Tchoupa A

PROVIDER: S-EPMC7481793 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids.

Kengmo Tchoupa Arnaud A Watkins Kate E KE Jones Rebekah A RA Kuroki Agnès A Alam Mohammad Tauqeer MT Perrier Sebastien S Chen Yin Y Unnikrishnan Meera M

Scientific reports 20200909 1

The Staphylococcus aureus type VII secretion system (T7SS) exports several proteins that are pivotal for bacterial virulence. The mechanisms underlying T7SS-mediated staphylococcal survival during infection nevertheless remain unclear. Here we report that S. aureus lacking T7SS components are more susceptible to host-derived antimicrobial fatty acids. Unsaturated fatty acids such as linoleic acid (LA) elicited an increased inhibition of S. aureus mutants lacking T7SS effectors EsxC, EsxA and Esx ...[more]

PMID: 32908165

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The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids.

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The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids.

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