[The CCM Project "Phenotypic and molecular screening methodologies for the detection of coloniza-tions due to carbapenem-resistant Enterobacterales (CRE)"].

Carbapenem-resistant Enterobacterales (CREs) are globally considered to be a major threat to public health. National and international guidelines emphasize the importance of routine active surveillance policies to prevent their transmission. Consequently, screening for the evaluation of the status of colonization by CREs in hospitalized patients in Italy is considered essential to contain and control the spread of these microorganisms and their evolution towards infection. The Italian Ministry of Health funding the CCM Project "Phenotypic and molecular screening methodologies for the detection of colonizations due to carbapenem-resistant enterobacterales (CRE)", carried out between February 2018 and January 2021 with the aim of evaluating phenotypic and molecular tests as methods able to detect patients colonized by CRE in Italian hospital setting. To assess the impact of the SARS-CoV-2 pandemic on CRE colonization, the observation period was divided into two periods: September 2018-September 2019 (first period) and October 2019-September 2020 (second period).As general objective of the project, the evaluation of the effectiveness of the methods has been appropriately foreseen. In addition, four specific objectives have been envisaged: 1. to standardize and to compare phenotypic and molecular methods, in terms of Turnaround Time (TAT); 2. to quantify the frequency of colonization at the admission and during hospitalization in Intensive Care Unit (ICU) and non-ICU wards; 3. to evaluate the effectiveness of screening interventions; 4. to provide activities that attest to the importance of screening.In order to evaluate the role of hospitalization in CRE-colonization, 11,063 patients were enrolled to perform rectal swabs on admission, and, if negative, weekly for three weeks during hospitalization. The data were collected in a dedicated IT platform.The molecular test demonstrated to be able to detect colonized patients and presence of resistance markers within 60 minutes from the sample arriving.The prevalence of CRE has increased during SARS-CoV-2 pandemic, especially in hospitals in South Italy. K. pneumoniae was the species most frequently associated with patients colonized by CRE.Training activities have been started for hospital staff, in order to reduce the frequency of colonization of patients. All the participating centres have defined the procedures to be applied locally for the screening of CRE colonized patients and have started screening activities.