Dual effect of Staphylococcus epidermidis DnaK on Staphylococcus aureus biofilm proteostasis and regulation

ABSTRACT: Staphylococcus aureus and Staphylococcus epidermidis, two Gram-positive bacteria commonly found in the human skin microbiota, form biofilms that contribute to skin dysbiosis and play a key role in conditions like acne and atopic dermatitis. The Calcitonin Gene-Related Peptide (CGRP) is a human peptide involved in skin inflammation. We previously showed that CGRP enhances the virulence of S. epidermidis MFP04 and that the DnaK chaperone protein is significantly overexpressed in the secretome of CGRP-activated virulent S. epidermidis. In this study, we explored a potential new role of S. epidermidis DnaK in biofilm formation in both S. aureus and S. epidermidis. We showed that recombinant S. epidermidis DnaK differentially affects biofilm formation, whether in two skin commensal staphylococcal strains (S. aureus MFP03 and S. epidermidis MFP04) or in a clinical S. aureus strain (CIP 107093). In the clinical strain S. aureus CIP 107093, biofilm formation was most strongly inhibited. This inhibition involves both the Substrate-Binding Domain and the Nucleotide-Binding Domain of DnaK. Proteomic analysis revealed that DnaK alters the S. aureus biofilm proteome, stabilizing proteins involved in protein degradation like ClpP and ETA, while downregulating key regulatory proteins involved in biofilm development such as SaeS and WalK. These results indicate that S. epidermidis DnaK may contribute to the regulation of S. aureus biofilm formation, suggesting a cross-species regulatory role of DnaK within the skin microbiota.

INSTRUMENT(S):

ORGANISM(S): Staphylococcus Aureus

SUBMITTER: Eléonore Bouscasse  

LAB HEAD: Yoan Konto-Ghiorghi

PROVIDER: PXD062742 | Pride | 2026-03-09

REPOSITORIES: Pride