FIMBUG · Heterogeneity in fimbrial length and abundance as a generic regulator of E. coli surface colonization
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2018-01-01 → 2019-12-31
- EU contribution
- €185,857
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Heterogeneity in fimbrial length and abundance as a generic regulator of E. coli surface colonization
Fimbriae are hair-like surface organelles found on many pathogenic bacteria. These structures are known to strongly promote formation of bacterial biofilms on tissue and biomaterials. This is an emerging problem in modern health care since biofilm implant-related infections are very difficult to eradicate and thus a main contributor to the development and spreading of antibiotic resistance. The mechanisms by which fimbriae promote biofilm formation and spreading of antibiotic resistance genes are not well understood. A better understanding of these processes could aid development of new antibacterial and antibiofilm strategies, for example based on material design. It is usually assumed that fimbriae provide bacteria with a way to form strong bonds to surfaces. However, several in vivo studies have shown that fimbriated bacteria that bind loosely to surfaces can form biofilms more efficiently. We hypothesized that this depends on the fact that a bacterium typically has many fimbriae (hundreds) and that it can bind with a variable number at a time. This way, bacteria may use fimbriae as a way to adjust their surface adhesion by shifting between monovalent, loose and mobile binding, to firm multivalent, immobile binding. We wanted to find out how this help E. coli bacteria to colonise surfaces and if it matters how many fimbriae the bacteria have. We found that fimbriae provide bacteria with a generic way to sense and change binding behavior in response to environmental conditions like surface composition and liquid flow environment. Importantly, we found that this helped bacteria to find positions on a surface where nutrients were abundant, thus enhancing cell growth. It also governed the organization of the early biofilm so that bacteria can interact with each other. The latter was found to have a strong effect on the spreading of antibiotic resistance genes.
Data: CORDIS, © European Union
Project objective
The aim of my research is to identify generic and physical mechanisms that regulate bacterial colonization and subsequent biofilm formation on biomaterial surfaces. This is an emerging problem in modern health care since biofilm implant-related infections are very difficult to eradicate and thus a main contributor to the development and spreading of antibiotic resistance. A key player is fimbriae; these hair-like surface organelles found on many bacteria are known to strongly promote biofilm formation, which is commonly attributed to fimbriae forming strong surface bonds. By recording in 3D the binding of single bacteria to nanopatterned surfaces we observed that this is not necessarily true; We found that fimbriae due to their heterogeneous distribution in length, rather then forming strong bonds provide bacteria a mean to adjust their surface adhesion, shifting between monovalent, loose and mobile binding to firm multivalent immobile binding modes in response to different flow conditions. This suggests a so far unexplored, regulatory role of fimbriae in the surface colonization process. My overarching aim is therefore to understand the influence of this mechanism on bacterial surface colonization. Specifically, I will test the hypothesis that physical and chemical/colloidal interactions are reflected in these structures and their biological function, providing bacteria evolved roles; In this case, that bacteria with certain fimbrial expression are fitter to be colonizers of certain environmental niches. To investigate this I will introduce new methods, allowing simultaneous read-out of a single-bacterium fimbrial expression and tracking of its movement in 3D. I foresee that this project and the training actions described herein will be the basis for a future scientific career focused on unraveling the intricate interplay between bacteria and their host surfaces.
Original text from CORDIS.
Participants
- GOETEBORGS UNIVERSITET · GoeteborgCoordinatorSweden
Links
Data: CORDIS, © European Union