Protocol for the carbapenem-resistant Enterobacter cloacae complex (CRECC) pilot survey

Since the survey of carbapenem- and/or colistin-resistant Enterobacterales (CCRE survey) conducted in 2019, the following developments show that the epidemiological situation in the EU/EEA continues to deteriorate:

• an increase in the incidence of carbapenem-resistant Klebsiella pneumoniae bloodstream infections;
• convergence of virulence and resistance in K. pneumoniae;
• newly emerging Enterobacterales species carrying carbapenemase genes;
• plasmid-mediated spread of carbapenemase genes;
• increasing detection of isolates of high-risk lineages of Escherichia coli carrying carbapenemase genes with a risk of community spread.

Previous European genomic surveys of CRE, including EuSCAPE, the CCRE survey 2019, and the CRE25 survey have focused on carbapenem-resistant K. pneumoniae species complex (SC) and carbapenem-resistant E. coli as the most frequent CRE. However, carbapenem-resistant Enterobacter cloacae complex (CRECC) has also emerged globally and is associated with various carbapenemases. Potential high-risk CRECC clones carrying carbapenemase genes have been described, and several European countries have experienced increasing numbers of cases, outbreaks and dissemination of carbapenemase-producing E. cloacae complex (ECC). A recent investigation from the European Antimicrobial Resistance Genes Surveillance Network (EURGen-Net) traced a cross-border outbreak of E. hormaechei ST1344 carrying blaNDM-5.

At the EURGen-Net network meeting in 2025, participants selected CRECC as the most relevant CRE for a pilot study on expanding European-level genomic surveillance of CRE. This document is intended as a protocol for such a EURGen-Net CRECC pilot survey in 2027.