GLASS technical note on the detection and reporting of colistin resistance

Overview

The scope of this technical note is to review current methods for the detection of colistin resistance and to provide a framework for its investigation. The document highlights the critical distinction between phenotypic detection of colistin resistance and genotypic detection of specific colistin resistance mechanisms, such as mcr and chromosomal mutations. Colistin resistance in Enterobacteriaceae and Acinetobacter baumannii is included in the WHO Global Antimicrobial Resistance Surveillance System (GLASS). Currently, however, reliable tests for phenotypic detection of colistin resistance for clinical and surveillance purposes are not widely available.

The technical note describes existing phenotypic methods for detecting colistin resistance, genotypic methods for detecting specific colistin resistance mechanisms and surveillance strategies for monitoring colistin resistance.

This is a rapidly evolving field with new resistance genes being identified regularly and new methods for phenotypic resistance testing being described, hence this document will be updated, as needed, to reflect these developments.