Table 4 Susceptibility profiles of selected Gram-negative species, P. aeruginosa (a) and H. influenzae (b)

Antimicrobial

Range

MIC₅₀

MIC₉₀

Susceptible

Intermediate

Resistant

 Amikacin

≤2 – <16

≤2

16

42 (100)

0 (0)

0 (0)

 Ceftazidime

≤1 – 8

4

8

42 (100)

0 (0)

0 (0)

 Ciprofloxacin

≤0.25 – ≥4

≤0.25

1

41 (97.6)

0 (0)

1 (2.4)

 Cefepime

≤1 – 8

2

<8

42 (100)

0 (0)

0 (0)

 Gentamicin

≤1 – ≥16

≤1

4

41 (97.6)

0 (0)

1 (2.4)

 Imipenem

≤1 – ≥16

2

4

38 (90.5)

1 (2.4)

3 (7.1)

 Levofloxacin

≤0.12 – ≥ 8

1

2

41 (97.6)

0 (0)

1 (2.4)

 Meropenem

0.125 – >32

1

8

35 (83.3)

2 (4.8)

5 (11.9)

 Piperacillin/Tazobactam

≤4 – ≥128

8

≥128

36 (87.8)

0 (0)

5 (12.2)

 Tobramycin*

≤1 – <4

≤1

<4

18 (100)

0 (0)

0 (0)

Antimicrobial

Range

MIC₅₀

MIC₉₀

Susceptible

Intermediate

Resistant

 Ampicillin

0.25 – >256

0.5

>256

22 (66.7)

1 (3)

10 (30.3)

 Amoxicillin/Clavulanate

0.5 – 8

1

4

41 (95.3)

0 (0)

2 (4.7)

 Ceftriaxone

.004 – 32

0.016

0.125

42 (97.7)

0 (0)

1 (2.3)

 Ciprofloxacin*

.008 – 1

0.032

0.5

27 (100)

0 (0)

0 (0)

 Levofloxacin

.008 – 2

0.064

0.5

30 (100)

0 (0)

0 (0)

 Trimethoprim/Sulfamethoxazole

0.032 – >32

0.5

>32

23 (50)

6 (13)

17 (36.9)