CRE Laboratory Testing and Protocols

Laboratory testing protocols for carbapenem-resistant Enterobacteriaceae (CRE) and information about submitting isolates for the case study on Carbapenem-resistant Klebsiella pneumoniae.

Laboratory testing and protocols

MDH PHL Special Microbiology Laboratory is available during regular business hours for consultation for CRE testing and result interpretation (651-201-5581).

Highly resistant Gram-negative organisms that meet the CRE surveillance definition should be submitted to the MDH PHL for further characterization, which may include polymerase chain reaction (PCR) testing for the presence of the blaKPC and/or blaNDM genes, and if applicable, blaVIM or other characterization.

Applying the surveillance definition in clinical laboratories/ hospitals

  • All laboratories should aim to implement the current Clinical and Laboratory Standards Institute (CLSI) breakpoints for carbapenems and cephalosporins.

  • MDH strongly encourages hospitals to use the CRE surveillance definition for hospital surveillance; however, we recognize there are limitations to its use such as:
    • Laboratories may not test all carbapenems/cephalosporins stated in the definition (e.g., card/panel only has one carbapenem), and/or
    • Laboratories may not have breakpoints that go low enough to detect CRE based on the January current CLSI breakpoints.
  • Given these limitations, some laboratories may need to modify the surveillance definition to align with their current laboratory practices. Laboratories that implement modifications to the CRE surveillance definition should communicate this to appropriate hospital personnel.

Updated Monday, August 03, 2015 at 12:48PM