CRE (carbapenem-resistant Enterobacterales) are identified based on disk diffusion or minimum inhibitory concentration (MIC) results (resistant to one of the carbapenems). This testing is sufficient for guiding patient therapy.
CP-CRE (carbapenemase-producing carbapenem-resistant Enterobacterales) are identified based on positive test results (e.g., MHT, CarbaNP, CIM) used to confirm the presence of carbapenemase production. If carbapenemase testing is negative, the organism is considered a CRE. Carbapenemase testing is used only for infection control or epidemiological purposes. Not all CRE are carbapenemase producers. The CP-CRE are of increased epidemiological concern.
