Project Background
The human oral microbiome consists of hundreds of different microorganisms [1] capable of forming biofilms on a variety of surfaces, including dental implants [2]. These biofilms consist of highly organized multispecies communities embedded within an extracellular polymer matrix [3]. Changes in the local conditions or poor oral hygiene can result in a shift of these natural biofilms to dysbiotic communities, where the increased incorporation of pathogens can lead to disease [4]. Pathogens that are usually unable to form biofilms by themselves, such as Porphyromonas gingivalis, embed and proliferate in established biofilms and trigger inflammatory reactions, leading to e.g., periodontal bone loss [7]. It is assumed that the incidence of oral diseases has a substantial impact on systemic health: WHO reports show that over 80% of the population in many countries suffer from infections such as caries or periodontitis [5,6].
While the use of modern sequencing techniques has revealed the biodiversity within these biofilms [8], process and molecular mechanisms of oral biofilm maturation remain to be addressed to a large extent. The aim of our research is to create an in vitro model of periodontal biofilms, using key colonizers and pathogens to find solutions for the effective treatment of natural and implant-associated infections. Implant surfaces in particular are susceptible to the formation of dysbiotic biofilms and understanding development, alteration, and composition of these is essential for developing and evaluating novel prevention strategies.
Aims of this project:
You will create and examine multispecies biofilms under anaerobic and flowing conditions that mimic the periodontal habitat. For this purpose, state-of-the-art fermentation technology will be used. Biofilms will be grown on medically relevant implant materials, and different biofilm removal methods will be assessed. Quantification of the different species will be achieved with qPCR and fluorescence in situ hybridization (“FISH”) methods; at later stages of the project, also next-generation sequencing approaches will be employed.
This project is part of a RCN-funded collaboration with the Department of Biomaterials at the Faculty of Odontology (MISFAITH, RCN 331752).
Methods:
- Microbiology
- Anaerobic cultivation methods
- Microfluidic flow cells
- Biotechnology methods: Fermentation using fully controlled systems
- Fluorescence Microscopy
- Fluorescence in situ hybridization (FISH)
- qPCR
- Next-generation sequencing methods
Requirements:
This project is best suited for students of the study programs Molecular Biology/Biochemistry, Cell Biology/Physiology, or Genetics/Developmental Biology - but students from all study programs and from other departments are welcome to contact us. Some background in Microbiology, Genetics or Biochemistry is an advantage.
Supervisors:
Prof. Dirk Linke, Dr. Athanasios Saragliadis, Jan-Ole Reese
About the group:
The research group of Prof. Linke is a very international and interdisciplinary environment, and is part of the EVOGENE section. The working language in the lab is English. The group excels in microbiology, biochemistry, and biotechnology methods, but we offer thesis topics for all MSc study programs. More information (also about other potential projects interesting for MSc students) can be found here:
https://www.mn.uio.no/ibv/english/research/sections/evogene/groups/linke/index.html
References
- Aas, J. A., Paster, B. J., Stokes, L. N., Olsen, I., & Dewhirst, F. E. (2005). Defining the normal bacterial flora of the oral cavity. Journal of clinical microbiology, 43(11), 5721-5732.
- Busscher, H. J., van der Mei, H. C., Subbiahdoss, G., Jutte, P. C., van den Dungen, J. J., Zaat, S. A., ... & Grainger, D. W. (2012). Biomaterial-associated infection: locating the finish line in the race for the surface. Science translational medicine, 4(153), 153rv10-153rv10.
- Do, T., Devine, D., & Marsh, P. D. (2013). Oral biofilms: molecular analysis, challenges, and future prospects in dental diagnostics. Clinical, cosmetic and investigational dentistry, 11-19.
- Marsh, P. D., & Zaura, E. (2017). Dental biofilm: ecological interactions in health and disease. Journal of clinical periodontology, 44, S12-S22.
- Do, T., Devine, D., & Marsh, P. D. (2013). Oral biofilms: molecular analysis, challenges, and future prospects in dental diagnostics. Clinical, cosmetic and investigational dentistry, 11-19.
- 6. Petersen, P. E., & Lennon, M. A. (2004). Effective use of fluorides for the prevention of dental caries in the 21st century: the WHO approach. Community dentistry and oral epidemiology, 32(5), 319-321.
- 7. Hajishengallis, G., Liang, S., Payne, M. A., Hashim, A., Jotwani, R., Eskan, M. A., ... & Curtis, M. A. (2011). Low-abundance biofilm species orchestrates inflammatory periodontal disease through the commensal microbiota and complement. Cell host & microbe, 10(5), 497-506.
- 8. Paster, B. J., Boches, S. K., Galvin, J. L., Ericson, R. E., Lau, C. N., Levanos, V. A., ... & Dewhirst, F. E. (2001). Bacterial diversity in human subgingival plaque. Journal of bacteriology, 183(12), 3770-3783.