Antibiotics are a mainstay of public health, but their use has increased exponentially leading to the emergence of antibiotic resistance. The R-GNOSIS (Resistance in Gram-Negative Organisms: Studying Intervention Strategies) project combines 5 international clinical studies, all supported by highly innovative microbiology, mathematical modelling and data-management, to determine - in the most relevant patient populations - the efficacy and effectiveness of cutting-edge interventions to reduce carriage, infection and spread of Multi-Drug Resistant Gram-negative Bacteria (MDR-GNB). All work-packages will progress science beyond the state-of-the-art in generating new and translational clinically relevant knowledge, through hypothesis-driven studies focussed on patient-centred outcomes.The 5 clinical studies will investigate the following interventions:•A Point-Of-Care-Testing guided management strategy to improve appropriate antibiotic prescription for uncomplicated UTI in primary care.•Gut decolonization in outpatients with intestinal carriage of MDR-GNB.•A “test and prescribe” strategy, based on rapid diagnostic testing of faeces for MDR-GNB to optimize antibiotic prophylaxis in colo-rectal surgery.•Contact Isolation of patients with ESBL-producing Enterobacteriaceae in general hospital wards.•Three Decolonization strategies in ICUs.Seven laboratories across Europe will perform microbiological analyses, as well as unique quantitative experiments. All information will be integrated by 3 groups of mathematical modellers into highly innovative models to better understand and predict future trends and effects of interventions. The studies and analyses proposed in R-GNOSIS will generate a step-change in identifying evidence-based preventive measures and clinical guidance for primary care and hospital-based physicians and health-care authorities, to combat the spread and impact of infections caused by MDR-GNB in Europe.