Periodic Reporting for period 1 - COBLIM (Label-free multimodal real-time imaging of phage-induced bacterial lysis)
Reporting period: 2023-10-01 to 2026-02-28
Antibiotic resistance is becoming a major global health challenge. Bacteria that were once easy to treat are increasingly able to survive existing medicines, making infections harder to cure. This creates an urgent need for new ways to combat bacterial infections and for better tools to study how bacteria interact with potential antibacterial agents. Since antimicrobial resistance threatens healthcare systems, public health, and the long-term effectiveness of existing treatments, it is not only a medical problem but also a broader societal and strategic challenge.
One promising option is the use of bacteriophages, or phages, which are viruses that infect bacteria. Because phages can kill bacteria, they are being studied as a possible alternative or complement to conventional antibiotics, especially for infections that no longer respond well to existing treatment. Leading health authorities recognise this potential, but they also stress that much more research is needed before phage-based treatments can be used more broadly and reliably.
An important challenge is that phage infection is still difficult to study in detail at the level of single bacterial cells. Many standard methods look at entire bacterial populations at once and mainly provide average, statistical information, which can hide important differences between individual cells and make it harder to understand why infection succeeds in some cases but not in others. There is therefore a growing need for methods that can observe these processes more directly and in greater detail.
This project was developed to help address that gap. Its goal was to advance microscopy tools for observing bacteriophage infection in real time and at the level of single bacterial cells. More specifically, the project worked towards a new imaging platform that can detect tiny phage particles, which are usually too small to be tracked by standard light microscopy, and link their presence to changes inside individual bacterial cells during infection. This is important because phage infection is a dynamic process: it depends not only on whether a phage reaches a bacterium, but also on how the bacterial cell responds under different biological conditions.
By bringing these two types of information together in a single experiment, the project aimed to provide a richer and more direct view of how phages cause bacterial cells to break apart in real time. This work helped establish new microscopy tools and experimental foundations for future research in microbiology, bioimaging, and phage science. In the longer term, it may improve our understanding of how phages act on bacteria and support the development and testing of phage-based approaches as a possible complement or alternative to conventional antibiotics.
One promising option is the use of bacteriophages, or phages, which are viruses that infect bacteria. Because phages can kill bacteria, they are being studied as a possible alternative or complement to conventional antibiotics, especially for infections that no longer respond well to existing treatment. Leading health authorities recognise this potential, but they also stress that much more research is needed before phage-based treatments can be used more broadly and reliably.
An important challenge is that phage infection is still difficult to study in detail at the level of single bacterial cells. Many standard methods look at entire bacterial populations at once and mainly provide average, statistical information, which can hide important differences between individual cells and make it harder to understand why infection succeeds in some cases but not in others. There is therefore a growing need for methods that can observe these processes more directly and in greater detail.
This project was developed to help address that gap. Its goal was to advance microscopy tools for observing bacteriophage infection in real time and at the level of single bacterial cells. More specifically, the project worked towards a new imaging platform that can detect tiny phage particles, which are usually too small to be tracked by standard light microscopy, and link their presence to changes inside individual bacterial cells during infection. This is important because phage infection is a dynamic process: it depends not only on whether a phage reaches a bacterium, but also on how the bacterial cell responds under different biological conditions.
By bringing these two types of information together in a single experiment, the project aimed to provide a richer and more direct view of how phages cause bacterial cells to break apart in real time. This work helped establish new microscopy tools and experimental foundations for future research in microbiology, bioimaging, and phage science. In the longer term, it may improve our understanding of how phages act on bacteria and support the development and testing of phage-based approaches as a possible complement or alternative to conventional antibiotics.
During the project, work focused on developing a new microscopy approach for studying how bacteriophages interact with bacteria. The main goal was to create an experimental system that could eventually make it possible to observe both tiny phage particles and changes inside bacterial cells during infection. To achieve this, the project brought together two complementary imaging methods: interferometric scattering-based detection for visualising very small particles, and fluorescence lifetime imaging for monitoring changes inside bacterial cells.
A major part of the work focused on building and integrating the new imaging platform and adapting it for biologically relevant measurements over longer periods of time. This led to the establishment of the core experimental setup and to improvements in the fluorescence lifetime imaging part of the system, allowing reliable monitoring of bacterial cells under controlled conditions. At the same time, the project identified suitable bacterial labeling strategies and measurement conditions compatible with phage-induced lysis, thereby providing an important basis for future experiments.
Overall, the project delivered the main technological and experimental foundations needed for this new multimodal imaging approach. Its main outcomes were the construction of the core imaging platform, the establishment of fluorescence-based measurements in bacterial cells, and the definition of suitable biological conditions for future phage infection studies. Although the full final application of the integrated system to routine real-time single-cell measurements remained beyond the project period, the project established the basis for future research in this area.
A major part of the work focused on building and integrating the new imaging platform and adapting it for biologically relevant measurements over longer periods of time. This led to the establishment of the core experimental setup and to improvements in the fluorescence lifetime imaging part of the system, allowing reliable monitoring of bacterial cells under controlled conditions. At the same time, the project identified suitable bacterial labeling strategies and measurement conditions compatible with phage-induced lysis, thereby providing an important basis for future experiments.
Overall, the project delivered the main technological and experimental foundations needed for this new multimodal imaging approach. Its main outcomes were the construction of the core imaging platform, the establishment of fluorescence-based measurements in bacterial cells, and the definition of suitable biological conditions for future phage infection studies. Although the full final application of the integrated system to routine real-time single-cell measurements remained beyond the project period, the project established the basis for future research in this area.
The project advanced the state of the art by laying the foundations for a new multimodal microscopy approach to studying bacteriophage-bacteria interactions at single-cell level. While existing techniques usually capture only one aspect of this process, the approach developed in the project was designed to connect two complementary types of information in one experimental framework: detection of tiny phage particles and monitoring of physiological changes inside bacterial cells. This creates the basis for a more informative way of studying phage infection and bacterial lysis in real time.
By the end of the project, the main results included the construction of the core imaging platform, the successful adaptation of fluorescence lifetime imaging for bacterial measurements, and the establishment of biological conditions suitable for future lysis-related experiments. These outcomes represent an important methodological advance and provide the experimental basis for future multimodal studies in this area.
The expected impact of these results is mainly scientific and technological. In the longer term, improved methods for studying how phages act on bacteria may support future research on phage-based approaches in the context of antimicrobial resistance. To ensure further uptake, the next steps will include final technical refinement, full validation of the integrated platform in biological experiments, and further scientific exploitation of the results.
By the end of the project, the main results included the construction of the core imaging platform, the successful adaptation of fluorescence lifetime imaging for bacterial measurements, and the establishment of biological conditions suitable for future lysis-related experiments. These outcomes represent an important methodological advance and provide the experimental basis for future multimodal studies in this area.
The expected impact of these results is mainly scientific and technological. In the longer term, improved methods for studying how phages act on bacteria may support future research on phage-based approaches in the context of antimicrobial resistance. To ensure further uptake, the next steps will include final technical refinement, full validation of the integrated platform in biological experiments, and further scientific exploitation of the results.