Staphylococcus epidermidis biofilms : new insights in their formation and development of control strategies
(2015)
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- Authors
- Supervisors
- Mahillon, Jacques
- Abstract
- Bacterial biofilms are the root cause of most chronic infections as- sociated with implanted materials. For the opportunistic pathogen Staphylococcus epidermidis, the development of biofilms is considered as a major virulence factor, responsible for its resilience in hospitals and in patients. There is a clear need to improve our understanding of the influences of the environment on S. epidermidis biofilm formation to propose more adapted clinical treatments to biofilms. This study aimed to gather more insights on the mechanisms of bacterial adhesion and aggregation, two essential phases of biofilm development and to develop methods to detect and control S. epidermidis in biofilms. First, the adhesion of S. epidermidis to Fibrinogen-coated surfaces was investigated. In particular, the contribution of SdrG, a cell surface adhesin, in the modulation of the adhesion of S. epidermidis to adsorbed fibrinogen was assessed. Secondly, a method to detect adhering bacteria by means of a impedimetric biosensor was developed. An original combination of optical and electrical measurements allowed to confirm the detection selectivity towards Staphylococci. Then, a novel type of aggregation was reported. Several isolates of Staphylococcus aureus and S. epidermidis were found to rapidly form large cell clumps in a reversible fashion. The implications of this phenotype on biofilm formation was also demonstrated. Finally, enzymes were used to challenge matureS. epidermidis biofilms. Lysostaphin, lysins of phage K and Twort and an analog of dispersin B were identified as potent candidates with anti-biofilm activity. Lysostaphin and lysin K could also cause significant cell lysis. These enzymes represent alternatives to the failure of antibiotics and disinfec- tants to eradicate biofilms.
- Affiliations
UCLouvain SST/ELI/ELIM - Applied Microbiology
Citations
Vanzieleghem, T. (2015). Staphylococcus epidermidis biofilms : new insights in their formation and development of control strategies. https://hdl.handle.net/2078.5/191283