Rapid high-resolution detection of colistin resistance in Gram-negative bacteria using flow cytometry: a comparison with broth microdilution, a commercial screening test and WGS.

Here, we present a rapid FCM-based AST assay for qualitative and quantitative testing of colistin resistance in E. coli and K. pneumoniae. The assay revealed probable chromosomal colistin resistance in K. pneumoniae that was not detected by BMD. If confirmed, these results question the reliability of BMD for colistin testing.