Periodic Reporting for period 1 - MATBFOB (MAThematical modelling of Biofilm FOrmation on Biomaterials)
Période du rapport: 2021-09-01 au 2024-08-31
Problem being addressed:
Biofilms play a pivotal role in healthcare-associated infections, especially those related to indwelling medical devices, such as intra-vascular and urinary catheters, cardiac pacemakers and orthopaedic implants. Many mathematical models have been developed to simulate and elucidate the main processes characterizing biofilm growth. The proposed project consists of a brief and precise experimental part for investigating the
initiation and progression of biofilm formation of pathogenic bacteria on implant surfaces through real-time monitoring and subsequent modelling of the stages of bacterial adhesion and biofilm formation.
Important for society
Biofilms can cause infections in healthcare settings, such as urinary tract infections, breast implant infections, and catheter-related bloodstream infections. Biofilm formation on implant surfaces shelters the bacteria and encourages persistence of infection. Furthermore, implant-infecting bacteria can elude innate and adaptive host defences as well as biocides and antibiotic chemotherapies. For the above reasons, exploring fundamental adhesion mechanisms of biofilm forming bacteria on a spectrum of implant materials is imperative for the development of innovative routes of preventive and therapeutic strategies of biofilm negation. Hence the proposed research is deemed to have a significant societal impact in terms of global health and wellbeing.
Overall objectives:
The experimental observations will be used to mathematically model the process of growth of biofilm on a biomaterial surface, considering the effect of interactions of microbes with specific substrates. The proposed research will help us to gain these understanding through the development of experimental observation based modelling approach considering the effect of substrate microbe interactions. Such realistic models can be used to design the most suitable and smart implant surfaces, capable of negating bacterial adhesion and biofilm formation.
Biofilms play a pivotal role in healthcare-associated infections, especially those related to indwelling medical devices, such as intra-vascular and urinary catheters, cardiac pacemakers and orthopaedic implants. Many mathematical models have been developed to simulate and elucidate the main processes characterizing biofilm growth. The proposed project consists of a brief and precise experimental part for investigating the
initiation and progression of biofilm formation of pathogenic bacteria on implant surfaces through real-time monitoring and subsequent modelling of the stages of bacterial adhesion and biofilm formation.
Important for society
Biofilms can cause infections in healthcare settings, such as urinary tract infections, breast implant infections, and catheter-related bloodstream infections. Biofilm formation on implant surfaces shelters the bacteria and encourages persistence of infection. Furthermore, implant-infecting bacteria can elude innate and adaptive host defences as well as biocides and antibiotic chemotherapies. For the above reasons, exploring fundamental adhesion mechanisms of biofilm forming bacteria on a spectrum of implant materials is imperative for the development of innovative routes of preventive and therapeutic strategies of biofilm negation. Hence the proposed research is deemed to have a significant societal impact in terms of global health and wellbeing.
Overall objectives:
The experimental observations will be used to mathematically model the process of growth of biofilm on a biomaterial surface, considering the effect of interactions of microbes with specific substrates. The proposed research will help us to gain these understanding through the development of experimental observation based modelling approach considering the effect of substrate microbe interactions. Such realistic models can be used to design the most suitable and smart implant surfaces, capable of negating bacterial adhesion and biofilm formation.
Work performed from the beginning of the project to the end of the period covered by the report and main results (based on the Work packages WPs):
1.WP1 Research objective 1 (Experiments to study initial stages of biofilm formation in real time with Pseudomonas aeruginosa PAO1):
Experiments of biofilm formation was performed with Pseudomonas aeruginosa PAO1, as well as with E coli K12 and Bacillus subtilis.
Polymers used: Polypropylene (PP), Polymethylene methacralate (PMMA), Polytetrafluoroethylene(PTFE), High density polyethylene (HDPE)
In addition to the above polymers(mentioned in the project proposal), biofilm was also grown on Polycarbonate(PC), and polymer microbeads of Polystyrene(PS) and PMMA of 25 um diameter.
Techniques used at different stages:
Initial stages of bacterial adhesion and biofilm growth was studied using:
Confocal Laser scanning microscope
Imaging Flow cytometer (Image stream from Amnis)
Biofilm growth was observed using:
Scanning electron microscope
Transmission electron microscope
Chemical composition of the biofilms on different substrates were studied with:
Renishaw Raman spectrometer
2.WP2 Research objective 2(Modelling the initial stages of biofilm growth considering the effects of substrate):
Effect of substrate has been observed experimentally using the above techniques
Time dependent data of biofilm growth on different substrates have been obtained experimentally.
The data has been used to derive the statistics of the inherent stages of bacterial adhesion and biofilm growth on different substrates.
3. WP3 Research objective 3 (Digital time-lapse microscopic imaging):
This part of the experiment was done using Confocal Laser scanning microscope and Imaging flow cytometer.
(Tried to do Digital time-lapse microscopic imaging at Prof Jeremy Webb's lab at the University of Southampton, but failed due to some interfering fluorescence issues of different proteins in biofilm matrix and conditioning layer)
4.WP4 Research objective 4 (Biofilm growth and spatial metapopulational model in 2 dimensions):
The data for this has been collected and I am actively collaborating with senior scientists from the University of Oxford and University of New Castle in order to sort this out, with vital inputs from Prof
Mario Recker and other scientists at the University of Exeter.
5. WP5 Research objective 5 (Spatio-temporal Individual Based model):
The basis of the model has been created, but I am actively pursuing this with Mario. We need to take into account the different substrates, hence facing a bit of delay. But this will be done within a
few weeks, as we need to run the program multiple times to verify it's plausibility.
6. WP6: Outreach and Dissemination: The research findings and output from the project have been presented as
1. Invited talks at various national and international conferences and
2. Research seminars at the Living Systems Institute, during weekly lab meetings
1.WP1 Research objective 1 (Experiments to study initial stages of biofilm formation in real time with Pseudomonas aeruginosa PAO1):
Experiments of biofilm formation was performed with Pseudomonas aeruginosa PAO1, as well as with E coli K12 and Bacillus subtilis.
Polymers used: Polypropylene (PP), Polymethylene methacralate (PMMA), Polytetrafluoroethylene(PTFE), High density polyethylene (HDPE)
In addition to the above polymers(mentioned in the project proposal), biofilm was also grown on Polycarbonate(PC), and polymer microbeads of Polystyrene(PS) and PMMA of 25 um diameter.
Techniques used at different stages:
Initial stages of bacterial adhesion and biofilm growth was studied using:
Confocal Laser scanning microscope
Imaging Flow cytometer (Image stream from Amnis)
Biofilm growth was observed using:
Scanning electron microscope
Transmission electron microscope
Chemical composition of the biofilms on different substrates were studied with:
Renishaw Raman spectrometer
2.WP2 Research objective 2(Modelling the initial stages of biofilm growth considering the effects of substrate):
Effect of substrate has been observed experimentally using the above techniques
Time dependent data of biofilm growth on different substrates have been obtained experimentally.
The data has been used to derive the statistics of the inherent stages of bacterial adhesion and biofilm growth on different substrates.
3. WP3 Research objective 3 (Digital time-lapse microscopic imaging):
This part of the experiment was done using Confocal Laser scanning microscope and Imaging flow cytometer.
(Tried to do Digital time-lapse microscopic imaging at Prof Jeremy Webb's lab at the University of Southampton, but failed due to some interfering fluorescence issues of different proteins in biofilm matrix and conditioning layer)
4.WP4 Research objective 4 (Biofilm growth and spatial metapopulational model in 2 dimensions):
The data for this has been collected and I am actively collaborating with senior scientists from the University of Oxford and University of New Castle in order to sort this out, with vital inputs from Prof
Mario Recker and other scientists at the University of Exeter.
5. WP5 Research objective 5 (Spatio-temporal Individual Based model):
The basis of the model has been created, but I am actively pursuing this with Mario. We need to take into account the different substrates, hence facing a bit of delay. But this will be done within a
few weeks, as we need to run the program multiple times to verify it's plausibility.
6. WP6: Outreach and Dissemination: The research findings and output from the project have been presented as
1. Invited talks at various national and international conferences and
2. Research seminars at the Living Systems Institute, during weekly lab meetings
Besides continuing making progress during the MATBFOB project, there was an agenda of continuous road mapping. This was to ensure that, by the end of the project, my progress is still beyond the state of the art.
Summarizing the progress beyond the state of the art, the following can be mentioned:
1. Efforts were made to test biofilm growth on medical devices (from Coloplast, UK) that are regularly used by patients all over Europe (UK and the EU). This has yielded positive results, and the need to alter the surface chemistry of the materials have been initiated.
2. Industrial collaborations have been initiated with Zeus, US to test growth of biofilms on the biomaterials that are used for manufacturing medical devices.
3. Morphology of biofilm bacteria and their variation on different substrates have been studied with impeccable details and precision using tools of imaging, electron microscopy, spectroscopy and incorporating image analysis techniques.
4. Efforts have been made to explore and relate biofilm growth on different polymers to their genetic constitution.
Impact:
The advancement of the biofilm research carried out in the MATBFOB project is expected to be a vital step forward in the understanding of effect of surfaces on biofilm proliferation. The experiments and modelling will help in decoding the 'surface characteristics of biofilm substrate/biofilm formation' relationship in great detail at different stages of biofilm development. It will also open new vistas in modelling the desired surfaces that can negate biofilms- and hence affect the societal economy in an appreciable way.
Summarizing the progress beyond the state of the art, the following can be mentioned:
1. Efforts were made to test biofilm growth on medical devices (from Coloplast, UK) that are regularly used by patients all over Europe (UK and the EU). This has yielded positive results, and the need to alter the surface chemistry of the materials have been initiated.
2. Industrial collaborations have been initiated with Zeus, US to test growth of biofilms on the biomaterials that are used for manufacturing medical devices.
3. Morphology of biofilm bacteria and their variation on different substrates have been studied with impeccable details and precision using tools of imaging, electron microscopy, spectroscopy and incorporating image analysis techniques.
4. Efforts have been made to explore and relate biofilm growth on different polymers to their genetic constitution.
Impact:
The advancement of the biofilm research carried out in the MATBFOB project is expected to be a vital step forward in the understanding of effect of surfaces on biofilm proliferation. The experiments and modelling will help in decoding the 'surface characteristics of biofilm substrate/biofilm formation' relationship in great detail at different stages of biofilm development. It will also open new vistas in modelling the desired surfaces that can negate biofilms- and hence affect the societal economy in an appreciable way.