Table 2.
Distributions of MICs for antimicrobial agents tested against 387 isolates of Bacteroides spp.
| Antimicrobial agent | No. of isolates (cumulative % inhibition) for which the antimicrobial agent MIC (μg/ml) wasa: |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.015 | 0.03 | 0.06 | 0.125 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | ≥64 | |
| Piperacillin-tazobactam | 35 (9.0) | 13 (12.4) | 16 (16.5) | 77 (36.4) | 65 (53.2) | 24 (59.4) | 29 (66.9) | 27 (73.9) | 31 (81.9) | 46 (93.8) | 20 (99.0) | 2 (99.5) | 2b (100) |
| Imipenem | 79 (20.4) | 108 (48.3) | 85 (70.3) | 66 (87.3) | 31 (95.4) | 13 (98.7) | 2 (99.2) | 1 (99.5) | 1 (99.7) | 1 (100) | |||
| Ertapenem | 57 (14.7) | 106 (42.1) | 55 (56.3) | 96 (81.1) | 38 (90.9) | 26 (97.7) | 6 (99.2) | 1 (99.5) | 2 (100) | ||||
| Doripenem | 246 (63.4) | 82 (84.5) | 28 (92.0) | 12c (95.1) | |||||||||
| Metronidazole | 2 (0.5) | 9 (2.8) | 45 (14.5) | 170 (58.4) | 122 (89.9) | 34 (98.7) | 4 (99.7) | 0 (99.7) | 1 (100) | ||||
| Tigecycline | 1 (0.3) | 4 (1.3) | 17 (5.7) | 87 (28.2) | 135 (63.0) | 38 (72.9) | 31 (80.9) | 43 (92.0) | 29 (99.5) | 2 (100) | |||
| Amoxicillin-clavulanate | 35 (9.0) | 138 (44.7) | 63 (61.0) | 66 (78.0) | 36 (87.3) | 25 (93.8) | 19 (98.7) | 5 (100) | |||||
| Moxifloxacin | 1 (0.3) | 15 (4.1) | 92 (27.9) | 50 (40.8) | 57 (55.5) | 41 (66.1) | 49 (78.8) | 33d (87.6) | |||||
| Clindamycin | 41 (10.6) | 29 (18.1) | 79 (38.5) | 53 (52.2) | 53 (65.9) | 10 (68.5) | 4d (69.6) | ||||||
| Cefoxitin | 2 (0.5) | 1 (0.8) | 42 (11.6) | 136 (46.8) | 74 (65.9) | 73 (84.8) | 59b (100) | ||||||
a
Susceptible MIC breakpoint is indicated in bold type for each antimicrobial agent.
b
Two/2 (piperacillin-tazobactam) and 21/59 (cefoxitin) isolate MICs were >64 μg/ml.
c
Nineteen/31 (doripenem) isolate MICs were >2 μg/ml; concentrations of doripenem of >2 μg/ml were not tested.
d
Forty-nine/82 (moxifloxacin) and 118/122 (clindamycin) isolate MICs were >16 μg/ml; concentrations of moxifloxacin and clindamycin of >16 μg/ml were not tested.