Forces Driving the Attachment of Staphylococcus epidermidis to Fibrinogen-Coated Surfaces

• Published in: Langmuir Vol. 29; no. 42; pp. 13018 - 13022
• Main Authors: Herman, Philippe, El-Kirat-Chatel, Sofiane, Beaussart, Audrey, Geoghegan, Joan A, Vanzieleghem, Thomas, Foster, Timothy J, Hols, Pascal, Mahillon, Jacques, Dufrêne, Yves F
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 22.10.2013
• Subjects: Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Fibrinogen - chemistry; Fibrinogen - metabolism; Fundamental and applied biological sciences. Psychology; Microbiology; Miscellaneous; Particle Size; Staphylococcus epidermidis; Staphylococcus epidermidis - chemistry; Staphylococcus epidermidis - cytology; Staphylococcus epidermidis - metabolism; Surface Properties; Atomic force microscopy; Staphylococcus epidermidis; Cell adhesion; Fibrinogen; Bacteria; Micrococcales; Micrococcaceae; Experimental study; Mechanism
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la4029172

Cell surface proteins of bacteria play essential roles in mediating the attachment of pathogens to host tissues and, therefore, represent key targets for anti-adhesion therapy. In the opportunistic pathogen Staphylococcus epidermidis, the adhesion protein SdrG mediates attachment of bacteria to the blood plasma protein fibrinogen (Fg) through a binding mechanism that is not yet fully understood. We report the direct measurement of the forces driving the adhesion of S. epidermidis to Fg-coated substrates using single-cell force spectroscopy. We found that the S. epidermidis–Fg adhesion force is of ∼150 pN magnitude and that the adhesion strength and adhesion probability strongly increase with the interaction time, suggesting that the adhesion process involves time-dependent conformational changes. Control experiments with mutant bacteria lacking SdrG and substrates coated with the Fg β6–20 peptide, instead of the full Fg protein, demonstrate that these force signatures originate from the rupture of specific bonds between SdrG and its peptide ligand. Collectively, our results are consistent with a dynamic, multi-step ligand-binding mechanism called “dock, lock, and latch”.