Table 1 MIC range, MIC ₅₀ (mg/L) and MIC ₉₀ (mg/L) values of 21 antimicrobial agents for Ec-ESBL and Ec-MRnoB isolates, and percentages of resistant isolates to the indicated agents (EUCAST breakpoints, except where indicated)

Amoxicillin

64-≥256

≥256

≥256

100

2-≥256

≥256

≥256

99

Amoxicillin-Clavulanic acid

8-16

4

8

41

8-≥128

8

32

83

Piperacillin

32-≥64

≥64

≥64

100

≤16-≥64

≥64

≥64

84

Piperacillin-Tazobactam

≤0.5-≥256

4

16

16

≤0.25-≥256

2

4

6

Cefoxitin ^a

≤2-32

≤2

8

5

≤2-≥32

4

8

8

Cefotetan ^a

≤1-8

≤1

≤1

0

≤1-≥32

≤1

≤1

2

Cefotaxime

32-≥128

≥128

≥128

100

≤0.5-128

≤0.5

≤0.5

5

Ceftazidime

≤0.5-≥128

2

16

23

≤0.5-128

≤0.5

≤0.5

8

Cefepime

≤1-≥32

≥32

≥32

96

≤1-4

≤1

<1

1

Aztreonam

2-≥64

16

≥64

96

≤0.5-32

≤0.5

≤0.5

6

Imipenem

≤0.5-1

≤0.5

≤0.5

0

≤0.5-2

≤0.5

≤0.5

0

Meropenem

≤0.5

≤0.5

≤0.5

0

≤0.5

≤0.5

≤0.5

0

Gentamicin

≤0.5-≥256

1

32

19

0.5-≥256

64

256

96

Tobramycin

0.5-256

1

8

17

≤0.25-256

8

32

89

Amikacin

≤0.5-8

2

4

0

1-8

2

4

0

Nalidixic acid ^a

1-≥256

≥256

≥256

89

1-≥256

≥256

≥256

98

Ciprofloxacin ^a

≤0.5-≥256

16

128

74

≤0.25-≥256

32

128

93

Tetracycline ^a

0.5-≥256

256

256

80

≤0.25-256

256

256

84

Doxycycline ^a

≤0.5-128

16

64

76

≤0.25-128

32

64

79

Tigecycline ^b

≤0.5-1

≤0.5

≤0.5

0

≤0.25-0.5

≤0.25

≤0.25

0

Trimethoprim-Sulfamethoxazole

≤0.5-≥32

≥32/608

≥32/608

67

≤0.5-≥32

≥32/608

≥32/608

98