Staphylococcus epidermidis DnaK alters biofilm formation and proteome in S. aureus CIP 107093
Staphylococcus aureus and Staphylococcus epidermidis, two Gram-positive members of the skin microbiota, form biofilms involved in dysbiosis and inflammatory skin diseases. We investigated the role of the molecular chaperone DnaK from S. epidermidis in biofilm formation. Recombinant DnaK modulates biofilm formation in a strain-dependent manner: it increases biofilm biomass in commensal strains but significantly reduces it in the clinical S. aureus strain CIP 107093. Using point mutants of DnaK, we show that the substrate-binding domain is required for this inhibitory effect. Proteomic analysis indicates that recombinant DnaK, added extracellularly, alters the biofilm proteome of S. aureus, affecting protein degradation systems and biofilm regulators, thus revealing a cross-species regulatory role within the skin microbiota.
Short bio
Yoan Konto-Ghiorghi is an Associate Professor (MCF-HDR) in Microbiology at the University of Rouen Normandie and a member of the CBSA laboratory (Bacterial Communication and Anti-infective Strategies). He completed his PhD at the Institut Pasteur studying the role of pili in adhesion and biofilm formation in Streptococcus agalactiae, where he contributed to demonstrating that these surface structures are key determinants of epithelial adhesion and bacterial biofilm formation. Seeking to broaden his expertise toward host biology and host-microenvironment interactions, he then conducted postdoctoral research at Stanford University in dermatology and hematology, where he investigated integrin signaling in epithelial cancers and cytokine signaling pathways in hematopoietic disorders.
His current research focuses on molecular signals shaping bacterial interactions within microbiomes, with a particular interest in the extracellular functions of the chaperone DnaK in regulating virulence and biofilm formation in skin bacteria. He led the ANR JCJC project “DnaK-Sensor”, which investigates how DnaK can act as an interspecies signaling factor modulating bacterial physiology within the skin microbiota.
His work combines microbiology, protein biochemistry and proteomics, and involves collaborations with the Institut Pasteur, the Centre de Biochimie Structurale in Montpellier, and international partners in South Korea (SNU).
Laboratory of the speaker
Laboratoire de Microbiologie CBSA (Communication Bactérienne et Stratégies Anti-infectieuses) – UR4312 Université de Rouen
Invited by
Philippe Gaudu
