Table 3. Activity of antimicrobial agents against confirmed CTX-M-15 β-lactamase-producing isolates of E. coli collected from UTIs in the USA during 2017.
| Antimicrobial Agent | MIC (μg/mL) | %Sa | %Ia | %Ra | |
|---|---|---|---|---|---|
| Range | 90% | ||||
| Levofloxacin | ≤0.03–>16 | >16 | 17.2 | 1.3 | 81.5 |
| Ciprofloxacin | ≤0.03–>4 | >4 | 15.2 | 1.3 | 83.4 |
| Trimethoprim-sulfamethoxazole | ≤0.5–>8 | >8 | 30.5 | - | 69.5 |
| Cefuroxime | >64 | >64 | 0.0 | 0.0 | 100b |
| 0.0 | 0.0 | 100c | |||
| Amoxicillin-clavulanate | 4–32 | 32 | 34.8 | 52.2 | 13.0 |
| Ampicillin-sulbactam | 4–>64 | 64 | 8.6 | 19.9 | 71.5 |
| Piperacillin-tazobactam | 0.25–>128 | 32 | 89.4 | 6.6 | 4.0 |
| Doripenem | ≤0.06–0.5 | ≤0.06 | 100 | 0.0 | 0.0 |
| Ertapenem | ≤0.008–1 | 0.25 | 97.1 | 2.9 | 0.0 |
| Imipenem | ≤0.12–0.5 | ≤0.12 | 100 | 0.0 | 0.0 |
| Meropenem | ≤0.015–0.5 | 0.06 | 100 | 0.0 | 0.0 |
| Cefepime | 1–>16 | >16 | 9.3 | 9.9 | 80.8d |
| Ceftazidime | 1–>32 | >32 | 14.6 | 13.2 | 72.2 |
| Amikacin | 1–>32 | 8 | 96.7 | 2.0 | 1.3 |
| Gentamicin | 0.5–>16 | >16 | 57.0 | 0.0 | 43.0 |
| Doxycycline | 0.5–>8 | >8 | 37.1 | 18.6 | 44.3 |
| Minocycline | 0.5–>32 | 16 | 74.3 | 8.6 | 17.1 |
| Tetracycline | 1–>16 | >16 | 32.9 | 0.0 | 67.1 |
a2018 CLSI Interpretive criteria; %S = percent susceptible, %I = percent intermediate, %R = percent resistant
bUsing oral breakpoints
cUsing parenteral breakpoints
dIntermediate interpreted as susceptible-dose-dependent