Abstract
The detection of carbapenem and colistin resistance using phenotypic methods has been agreed between the EURL-PH-AMR and ECDC, following discussions with the members of EURGen-Net and the distribution of a questionnaire to national reference laboratories (NRLs) concerning methods and capabilities in the respective participating countries. Many laboratories are restricted to using their regular routine methods - the difference in sensitivity is clear from Table 1 - and it was decided to offer both alternatives - clinical breakpoints and screening cut-off values. It will be important to devise a reporting method that clearly distinguishes between the breakpoints and methods used by individual laboratories. For colistin, the methodology is straightforward - only broth microdilution and the breakpoints listed in Table 2 are accepted.