Characterization of the adhesin-mediated interaction between Staphylococcus epidermidis and implant surfaces to develop an antibody-based therapy for peri-implant inflammation

• Applicants: Professor Dr. Ralf Bürgers; Professor Dr. Martin Gosau
• Subject Area: Dentistry, Oral Surgery
• Term: from 2012 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 226645895

The surfaces of dental implants are highly micro- and macro-structured to enable quick and intensive osseointegration into the surrounding alveolar bone. Unfortunately, these surface modifications additionally exhibit ideal conditions for the initial adhesion of oral microorganisms and the formation of pathogenic biofilms, which in turn may cause peri-implant inflammation and result in implant loss in the long term. Until now, none of the present therapies against peri-implantitis, which mostly have been adopted from periodontology, has proven to be clinically effective. Therefore, it is of great clinical relevance to develop alternative strategies to prevent or reduce the microbial colonization of the implant surface in the early stages of peri-implant mucositis. Furthermore, many essential microbial processes in the pathogenesis of peri-implant infections are still unknown. For example, information on the surface proteins of microorganisms that enable the specific adhesion of bacteria to implant substrata is rare. Therefore, the primary aim of the proposed research project is to use proteomic analysis of Staphylococcus epidermidis proteins to detected and decode these surface proteins (adhesins). S. epidermidis is not only associated with infections of dental implants, but is also involved with peri-implant infections throughout the body. In order to identify adhesins of S. epidermidis that are responsible for the adhesion to implant surfaces, bacterial cultures are grown planctonic in conventional nutrient broth and in nutrient broth adherent on implants. Both proteomes will be analyzed in terms of differing protein expression. To characterize the adhesins, the corresponding genes encoding the proteins will be inactivated and the modified strains will be compared with the initial bacterial strains regarding their adhesion potential on implants by using different analytical methods. Antibodies are obtained with recombinant proteins in mice in order to identify specific micro-organisms associated with peri-implantitis and to inhibit adhesion of S. epidermidis on implants. The overall aim of the research project is to characterize the interaction between bacterial adhesins and implant substrata and to use this knowledge to implement a newly antibody-based therapeutic strategy against peri-implant infections.

• DFG Programme: Research Grants
• International Connection: Denmark
• Participating Persons: Dr. Hans-Christian Beck; Professor Dr. Christian Morsczeck; Professor Dr. Udo Reischl