Our project is aimed at the development of a simple screening system, which allows the rapid identification and characterization of substances that disturb c-di-AMP homeostasis in pathogenic bacteria. By developing this system, we believe we can help scientist and pharmaceutical companies worldwide to find new and more effective antibiotics against Gram-positive pathogens, for which c-di-AMP is essential. The screening system will be established in the non- pathogenic bacterium E. coli.