Table 1 MIC determination for selected mutants against different beta-lactams.

From: Exploring mutational possibilities of KPC variants to reach high level resistance to cefiderocol

Mutants

Ancestral allele

Ancestral mutation

Acquired mutations

MIC (mg/L)

AMP

CEP

FAZ

FOX

AXO

CTX

POD

FEP

CAZ

CZA

T/C

MEM

IMP

PTZ

F/C

FDC

KPC-2

–

–

 

> 16

> 16

> 16

16

32

16

> 32

4

16

0.5

16

4

2

> 64

2

0.25

KPC-3

–

H274Y

 

> 16

> 16

> 16

16

32

16

> 32

8

64

1

32

4

2

> 64

4

0.12

KPC-33

–

D179Y

 

< 8

16

< 8

8

8

4

8

< 1

128

24

2

< 1

< 0.5

< 4

< 0.12

2

KPC-2n2

KPC-2

–

D179Y D209V

< 8

> 16

< 8

8

8

4

16

< 1

128

32

2

< 1

< 0.5

< 4

0.5

> 32

KPC-3n4

KPC-3

H274Y

L169P

16

16

< 8

8

8

4

16

2

> 128

12

2

< 1

< 0.5

< 4

< 0.12

2

KPC-33n6

KPC-33

D179Y

R6H F20L

< 8

16

< 8

8

8

8

16

< 1

> 128

64

2

< 1

< 0.5

< 4

< 0.12

8

plasmid KPC-2n2 in naïve E. coli Top10

KPC-2

–

D179Y D209V

< 8

> 16

< 8

8

8

4

16

< 1

128

32

2

< 1

< 0.5

< 4

0.25

2

plasmid KPC-3n4 in naïve E. coli Top10

KPC-3

H274Y

L169P

16

16

< 8

8

8

4

16

2

> 128

12

2

< 1

< 0.5

< 4

< 0.12

0.5

plasmid KPC-33n6 in naïve E. coli Top10

KPC-33

D179Y

R6H F20L

< 8

16

< 8

8

8

8

16

< 1

> 128

64

2

< 1

< 0.5

< 4

< 0.12

2

  1. AMP, Ampicillin ; CEP, Cephalothin, FAZ, Ceftazolin ; FOX, Cefoxitin ; AXO, Ceftriaxone ; CTX, Cefotaxime ; POD, Cefpodoxime ; FEP, Cefepime ; CAZ, Ceftazidime ; CZA; Ceftazidime-avibactam ; T/C, Ceftazdime/clavulanate ; MEM, Meropenem ; IMP, Imipenem ; PTZ, Piperacillin/tazobactam ; F/C, Cefotaxime/clavulanate; FDC, Cefiderocol.
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