There exists an urgent need to advance methods for detection of bacteria in the body, primarily in the context of infectious disease research. Real-time in vivo analysis empowers the investigator with the ability to non-invasively assess bacterial activity over time, as well as host responses to infection and interventions. Optical Imaging (OI) modalities are based on the detection and quantification of bioluminescent or fluorescent light from the subject and represent powerful yet cost-efficient and convenient systems. By labelling of bacteria and/or host cells of interest, both bacterial and host responses can be assessed in rapid, high-throughput analyses, providing spatial, temporal and quantitative read-out, without the need for radioactivity. There is a large and increasing market need for efficient reagents for in vivo bacterial imaging. We aim to develop improved in vivo imaging and ex vivo analysis methods for the study of bacterial infectious diseases and host immune response to infections, to address the current need across the range of fields of infectious disease and vaccine research. A broad skill set is required in this rapidly advancing field, involving exposure to laboratory science, imaging technology, commercialisation of research and industrial processes. By bringing together an international network of leaders in the fields of molecular imaging, infectious disease, vaccine research and industry, we propose to address the current paucity of technology for imaging of bacteria in research animals. GSK Vaccines is a world leader in development of vaccines for infectious diseases, and will provide an industrial steer from the project outset. Through combining the various specialities of this IAPP, the proposed work programme will facilitate transfer of knowledge among project partners, promote the development and training of staff in both academia and industry, as well as providing the industry partner with new R&D tools.