TABLE 1.
Summary of ceftazidime-avibactam activities tested against the organisms and resistant subsets included in this report (United States, 2012)
| Organism/resistant subset | No. of isolates | No. of isolates (cumulative %) inhibited at a MIC (μg/ml) ofa: |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.015 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | >16 | ||
| Enterobacteriaceae | 8,640 | 185 (2.1) | 1,043 (14.2) | 2,748 (46.0) | 3,052 (81.3) | 1,043 (93.4) | 373 (97.7) | 139 (99.3) | 30 (99.7) | 9 (99.8) | 12 (99.9) | 4 (>99.9) | 2 (100.0) |
| E. coli | 2,767 | 131 (4.7) | 210 (12.3) | 1,171 (54.6) | 1,050 (92.6) | 167 (98.6) | 28 (99.6) | 9 (>99.9) | 1 (100.0) | ||||
| ESBL phenotype | 328 | 5 (1.5) | 6 (3.4) | 56 (20.4) | 168 (71.6) | 61 (90.2) | 22 (97.0) | 9 (99.7) | 1 (100.0) | ||||
| K. pneumoniae | 1,847 | 22 (1.2) | 67 (4.8) | 625 (38.7) | 725 (77.9) | 217 (89.7) | 121 (96.2) | 49 (98.9) | 16 (99.7) | 3 (99.9) | 0 (99.9) | 0 (99.9) | 2 (100.0) |
| ESBL phenotype | 296 | 5 (1.7) | 0 (1.7) | 14 (6.4) | 58 (26.0) | 60 (46.3) | 89 (76.4) | 49 (92.9) | 16 (98.3) | 3 (99.3) | 0 (99.3) | 0 (99.3) | 2 (100.0) |
| Meropenem nonsusceptibleb | 115 | 2 (1.7) | 10 (10.4) | 14 (22.6) | 43 (60.0) | 29 (85.2) | 12 (95.7) | 3 (98.3) | 0 (98.3) | 0 (98.3) | 2 (100.0) | ||
| K. oxytoca | 442 | 29 (6.6) | 205 (52.9) | 148 (86.4) | 41 (95.7) | 10 (98.0) | 9 (100.0) | ||||||
| ESBL phenotype | 44 | 2 (4.5) | 18 (45.5) | 10 (68.2) | 7 (84.1) | 7 (100.0) | |||||||
| P. mirabilis | 683 | 12 (1.8) | 437 (65.7) | 206 (95.9) | 23 (99.3) | 4 (99.9) | 1 (100.0) | ||||||
| ESBL phenotype | 33 | 11 (33.3) | 16 (81.8) | 5 (97.0) | 1 (100.0) | ||||||||
| E. cloacae | 951 | 7 (0.7) | 11 (1.9) | 47 (6.8) | 453 (54.5) | 274 (83.3) | 109 (94.7) | 41 (99.1) | 6 (99.7) | 3 (100.0) | |||
| Ceftazidime nonsusceptiblec | 200 | 3 (1.5) | 1 (2.0) | 3 (3.5) | 18 (12.5) | 49 (37.0) | 82 (78.0) | 35 (95.5) | 6 (98.5) | 3 (100.0) | |||
| E. aerogenes | 357 | 2 (0.6) | 11 (3.6) | 98 (31.1) | 155 (74.5) | 64 (92.4) | 24 (99.2) | 2 (99.7) | 0 (99.7) | 0 (99.7) | 0 (99.7) | 1 (100.0) | |
| Ceftazidime nonsusceptiblec | 82 | 2 (2.4) | 1 (3.7) | 2 (6.1) | 23 (34.1) | 37 (79.3) | 14 (96.3) | 2 (98.8) | 0 (98.8) | 0 (98.8) | 0 (98.8) | 1 (100.0) | |
| M. morganii | 295 | 3 (1.0) | 141 (48.8) | 94 (80.7) | 33 (91.9) | 16 (97.3) | 5 (99.0) | 2 (99.7) | 0 (99.7) | 0 (99.7) | 1 (100.0) | ||
| C. koseri | 186 | 2 (1.1) | 9 (5.9) | 101 (60.2) | 57 (90.9) | 12 (97.3) | 1 (97.8) | 4 (100.0) | |||||
| C. freundii | 185 | 2 (1.1) | 29 (16.8) | 84 (62.2) | 46 (87.0) | 13 (94.1) | 8 (98.4) | 2 (99.5) | 0 (99.5) | 0 (99.5) | 1 (100.0) | ||
| S. marcescens | 506 | 2 (0.4) | 48 (9.9) | 250 (59.3) | 142 (87.4) | 49 (97.0) | 10 (99.0) | 2 (99.4) | 1 (99.6) | 1 (99.8) | 1 (100.0) | ||
| P. vulgaris | 153 | 70 (45.8) | 74 (94.1) | 8 (99.3) | 0 (99.3) | 1 (100.0) | |||||||
| Providencia spp. | 268 | 6 (2.2) | 54 (22.4) | 50 (41.0) | 66 (65.7) | 60 (88.1) | 11 (92.2) | 5 (94.0) | 3 (95.1) | 2 (95.9) | 10 (99.6) | 1 (100.0) | |
| P. aeruginosa | 1,967 | 3 (0.2) | 2 (0.3) | 18 (1.2) | 105 (6.5) | 779 (46.1) | 608 (77.0) | 273 (90.9) | 119 (96.9) | 38 (98.9) | 22 (100.0) | ||
| Meropenem nonsusceptibled | 354 | 4 (1.1) | 39 (12.1) | 84 (35.9) | 104 (65.3) | 78 (87.3) | 28 (95.2) | 17 (100.0) | |||||
| Ceftazidime nonsusceptiblee | 330 | 1 (0.3) | 26 (8.2) | 76 (31.2) | 86 (57.3) | 82 (82.1) | 37 (93.3) | 22 (100.0) | |||||
| Acinetobacter spp. | 321 | 2 (0.6) | 0 (0.6) | 7 (2.8) | 8 (5.3) | 43 (18.7) | 40 (31.2) | 70 (53.0) | 151 (100.0) | ||||
a
Underlined values represent the percentages inhibited at the CLSI susceptible breakpoint for ceftazidime alone (11).
b
Defined according to the CLSI nonsusceptibility breakpoint of ≥2 μg/ml (11).
c
Defined according to the CLSI nonsusceptibility breakpoint of ≥8 μg/ml (11).
d
Defined according to the CLSI nonsusceptibility breakpoint of ≥4 μg/ml (11).
e
Defined according to the CLSI nonsusceptibility breakpoint of ≥16 μg/ml (11).