Pseudomonas aeruginosa causes severe infections in hospitalized patients. The worldwide emergence of carbapenem-resistant P. aeruginosa (CRPA) makes infections by these pathogens almost untreatable. The World Health Organization now ranks CRPA highest in the list of 'urgent threats'. Information for action to prevent further emergence has to come from insight into sources and transmission routes through smart surveillance. At present, a smart surveillance strategy is not available for CRPA. The aim of this project is to develop a globally-applicable smart surveillance strategy to guide action against the spread of CRPA. Since P. aeruginosa prefers moist niches, we will focus on the human-water interface. First, highly-sensitive methods to detect CRPA in specific environmental and human niches will be developed. Subsequently, CRPA will be collected in three study sites with increasing prevalences of CRPA, increasingly warmer climates, and different water situations: Rotterdam (The Netherlands), Rome (Italy), Jakarta (Indonesia). CRPA will be searched for in a variety of niches in the environment outside and inside the hospital, and in healthy humans and hospitalized patients. Whole genome sequencing will be performed to compare the CRPA from different sources and identify transmission routes. Our project will provide insight into the relative contribution of the different potential reservoirs of CRPA to its spread in different settings which will be used for the development of a globally-applicable surveillance strategy for CRPA to guide preventive actions.

Inclusion Criteria healthy individuals:

• All healthy individuals (i.e., not hospitalized) aged 18 years or older and living in a "high-risk area" in Rotterdam, Rome or Jakarta.

Exclusion Criteria healthy individuals:

• No signed consent sheet.

Inclusion Criteria patients:

• Must be aged 18 years or older;
• Should be capable of providing answers to the questions in the questionnaire by himself/herself;
• Should have a minimum expected length of stay of at least 24 hours;
• Inclusion only once during the sampling year.

Exclusion Criteria patients:

• Cystic fibrosis patients
• No signed consent sheet.

Healthy volunteers are individuals living in "high-risk areas" in one of the three cities. "High-risk areas" are areas that we expect to have a high prevalence of CRPA which may affect humans.

Patients will be included within 48 hours of their admission to the hospital (non-critical medical and surgical wards) in one of the three cities. The three participating hospitals are all university hospitals.

Metadata for human, hospital environment, and water data are available through the data repository DataverseNL (https://doi.org/10.34894/1OFFVG). Raw reads, assembly data and metadata are available on the International Pseudomonas Consortium Database (https://ipcd.ibis.ulaval.ca/). Deidentified individual participant data and data from environmental, including water, sources that underlie the results reported in this Article can be shared with researchers following submission of a methodologically sound proposal, approval by the SAMPAN Project Board, and can only be made available upon signing a Data Transfer Agreement. Proposals should be directed to the corresponding author or the corresponding author's department (projectmanagement.mmiz@erasmusmc.nl).