Fig. 1: Flow chart of received colistin-resistant and colistin-susceptible isolates.

Methods used to decide which isolates met study inclusion criteria are denoted in the green square. Reasons for rejection of isolates for inclusion in the study are denoted in the red squares. COLR-EK: colistin-resistant E. coli or K. pneumoniae, COLS-EK: colistin-susceptible E. coli or K. pneumoniae, MALDI-TOF: matrix-assisted laser desorption/ionisation time-of-flight analyser, MIC: minimum inhibitory concentration, PCR: polymerase chain reaction.