The Baha Microbiome Case Control Study

The Bone-Anchored Hearing Aid (Baha) system consists of an implanted part and sound processor. The system provides a hearing solution for a subgroup of patients who cannot sufficiently profit from conventional hearing aids. Disadvantageous are its high rate (up to 40%) of associated peri-implant dermatitis. This research project is part of an attempt to reduce the amount of peri-implant dermatitis. Besides an attempt of Holgers to identify the skin flora in relation to infection around the abutment using a standard culture which yielded limited and no clinically relevant results, little is known about the microbiome on the abutment or its interaction with the commensal skin flora. Moreover, conventional cultures are not very sensitive in identifying bacteria. In 2010, Budding et al. introduced IS-pro. Is-pro is a novel 16S-23S rDNA interspace (IS)- region-based profiling method. This technology was devised to enable high-throughput molecular fingerprinting of microbioma. Since IS-pro is quick and relatively inexpensive, these environments can also be monitored over time by repeating the test. This paves the way for researching the microbiome on the abutment and it could enable clinically objective follow up of treatments in vivo using the human as a host. This technique allows researchers to even discover unknown, previously unidentified bacteria. Additionally, Scanning Electron Microscopy will be used to assess the spatial distribution and composition of bacteria on the abutment. The first step, using these techniques, is to determine the bacteria which inhabit the abutment also in relation to the surrounding skin. Additionally, the relationship with skin-implant infections and the effect of treatments will be monitored. Depending on these primary scientific results, a subsequent study will be devised to study (experimental) treatments in a randomized, controlled fashion. Objectives of the study: 1. To identify the bacterial flora on the abutment in a phylum/spec