Biofilms are bacterial aggregates attached to moist surfaces.Understanding the biofilms is important to cope with many infections acquired in hospitals and to solve industrial problems.The project expects to provide models able to reproduce the filaments generated by Pseudomonas strains in flows.The project expects to benefit the whole society taking a strong potential impact in public wellness.It might affect the way some medical or food devices are designed to prevent infections and poisoning due to biofilm formation.The donor partner, University of Iceland, has been working on mathematical descriptions of the collective behavior of myxobacteria and of other biological aggregates.The Project Promoter has been working on hybrid continuum-stochastic models for bacterial biofilms.The expertise of both researchers is complementary and both will be benefited from an interchange of ideas and information.The combined expertise of both researchers should contribute to make progress in the biofilm topic, opening new research lines with strong potential impact in public wellness.
Summary of project results
The goal of the project was to develop mathematical models for biofilms, oriented to medical applications, Bacterial biofilms have a strong impact on natural, industrial and medical environments. A better understanding of the influence of external variables on their evolution may help to control their beneficial (bioremediation) or damaging (biocorrosion, biofouling, water and food poisoning, hospital acquired infections) effects. Recent experiments reveal detailed information about how small biofilms develop in solid/liquid and solid/air interfaces, and also about factors that influence their resistance to toxicants and antibiotics. New information has to be incorporated in new mathematical models. Prof. Carpio had previous experience on hybrid discrete-continuum modelling of biofilms, and Prof. Birnir on Dynamic Energy Budget (DEB) models for bacterial colonies. The idea was to combine both strategies to obtain improved models of biofilm response to external parameters. Partners developed a preliminary model of Pseudomonas biofilm response to antibiotics and started a research in the medical literature to locate experimental data they could use to calibrate and test the model. The model combines a hybrid discrete-continuum description of the biofilm structure and a DEB description of bacterial response to antibiotics. In 2015, they made progress fitting parameters and mechanism to reproduce some experimental measurements. They also made progress developing computational frameworks to reproduce and investigate patterns experimentally observed with Pseudomonas biofilms in flows and Bacillus on agar surfaces. This work took the form of a collaboration with B. Einarsson, pursuing earlier work started during 2010 in the frame of a visit within the previous NILS programme. Main benefit of the project might be a better understanding of antibiotic effects in biofilms and the development of new antibiofilm therapies. This may have a social and economic impact, contributing to the well-being of the population, and reducing the incidence and cost of hospital acquired infections in the healthcare systems.
Summary of bilateral results
These results contributed to strengthen the existing links between both research teams but also with the groups performing this experiments in Harvard and Princeton Universities in the United States. Besides, once partners have calibrated two experiments with antibiotics on their current biofilm model, partners plan to contact the experimental groups performing such experiments, mainly in Denmark, to explore the possibility of using the model to predict the success of different anibiofilm antibiotic therapies and to better understand the mechanisms of antibiotic resistance in biofilms. Prof. Birnir’s group will be collaborating with Prof. Carpio’s group in a three years research project recently granted by the Spanish Ministry of Economy and Science. Partners expect to exchange PhD students. Besides biofilm modelling, they have identified new topics of common interest, such as the long time behaviour and control of blood vessel networks in angiogenesis models.