TABLE 2

MICs, molecular features, and genotyping analysis of K. pneumoniae isolates carrying the pmrB gene mutation and of isolate AF1a, the isogenic colistin-susceptible counterpart of AF1b

IsolateCountry of isolationMIC (μg/ml) fora:Colistin profilebPmrB amino acid changeCarbapenemaseESBLcAdditional β-lactamasesMLSTdPFGEe pulsotype
ERTIPMMEMDORCST
AF1aSouth Africa>32>32>32>320.125SWTfOXA-181CTX-M-15TEM-1, SHV-1ST141
AF1bSouth Africa>32>32>32>323RT157POXA-181CTX-M-15TEM-1, SHV-1ST141
C3Colombia>32>32>32>324RT157PKPC-3NoneTEM-1, SHV-1ST2582
C4Colombia>32>32>32>324RT157PKPC-3NoneTEM-1, SHV-1ST2582
C19Colombia0.250.190.0940.0644RT157PNoneNoneTEM-1, SHV-1ST153
T2Turkey16>32>32246RT157POXA-48CTX-M-15TEM-1, SHV-1, OXA-1ST1014
T3Turkey16>32>32246RT157POXA-48CTX-M-15TEM-1, SHV-1, OXA-1ST1014
  • a ERT, ertapenem; IPM, imipenem; MEM, meropenem; DOR, doripenem; CST, colistin.

  • b R, resistant; S, susceptible.

  • c ESBL, extended-spectrum β-lactamase.

  • d MLST, multilocus sequence type; ST, sequence type.

  • e PFGE, pulsed-field gel electrophoresis.

  • f WT, wild type.