TABLE 4.
In vitro activity of meropenem alone and combined with xeruborbactam at 4 and 8 µg/mL and comparator BLI combination agents against surveillance isolates of carbapenem-resistant strains of Enterobacterales according to carbapenemase production a
| MEM | MEM + XER at 4 µg/mL | MEM + XER at 8 µg/mL | FEP | FEP + TAN at 4 µg/mL | CAZ + AVI at 4 µg/mL | MEM + VAB at 8 µg/mL | IMP + REL at 4 µg/mL | |
|---|---|---|---|---|---|---|---|---|
| All | N = 1027 | N = 969 | N = 507 | |||||
| MIC50 | 32 | 0.06 | ≤0.03 | >32 | 1 | 1 | 4 | 1 |
| MIC90 | >32 | 0.5 | 0.25 | >32 | 8 | >32 | >32 | 32 |
| % Inhibited b | 30.20 | 98.30 | 99.60 | 10.80 | 92.80 | 69.60 | 57 | 51.30 |
| No MBL | N = 715 | N = 677 | N = 339 | |||||
| MIC50 | 16 | 0.06 | ≤0.03 | >32 | 0.5 | 1 | 1 | 0.25 |
| MIC90 | >32 | 0.25 | 0.125 | >32 | 4 | 2 | 32 | 4 |
| % Inhibited | 39.40 | 99.40 | 100.00 | 15.50 | 97.60 | 99.30 | 79.9 | 76.70 |
| KPC | N = 369 | N = 347 | N = 193 | |||||
| MIC50 | 32 | ≤0.03 | ≤0.03 | >32 | 0.25 | 1 | ≤0.03 | 0.125 |
| MIC90 | >32 | 0.125 | 0.06 | >32 | 2 | 4 | 2 | 0.5 |
| % Inhibited | 29.50 | 98.90 | 100.00 | 11.70 | 99.50 | 99.20 | 98.6 | 97.40 |
| OXA-48 | N = 247 | N = 236 | N = 96 | |||||
| MIC50 | 32 | 0.06 | ≤0.03 | >32 | 1 | 1 | 16 | 2 |
| MIC90 | >32 | 0.125 | 0.125 | >32 | 4 | 2 | >32 | 8 |
| % Inhibited | 37.20 | 100.00 | 100.00 | 21.50 | 97.60 | 100.00 | 41.9 | 27.10 |
| Non-CP CRE | N = 99 | N = 94 | N = 50 | |||||
| MIC50 | 8 | 0.25 | 0.125 | >32 | 2 | 1 | 1 | 0.25 |
| MIC90 | 16 | 1 | 0.5 | >32 | 8 | 4 | 4 | 1 |
| % Inhibited | 81.80 | 100.00 | 100.00 | 15.20 | 90.90 | 98.00 | 98.9 | 92 |
| MBL | N = 310 | N = 168 | ||||||
| MIC50 | >32 | 0.06 | ≤0.03 | >32 | 1 | >32 | >32 | 32 |
| MIC90 | >32 | 4 | 1 | >32 | 16 | >32 | >32 | >64 |
| % Inhibited | 9.00 | 95.80 | 98.70 | 0.00 | 81.70 | 1.60 | 9.6 | 0 |
| NDM | N = 287 | N = 157 | ||||||
| MIC50 | >32 | 0.06 | ≤0.03 | >32 | 2 | >32 | >32 | 32 |
| MIC90 | >32 | 4 | 1 | >32 | 32 | >32 | >32 | >64 |
| % Inhibited | 6.30 | 95.80 | 99.00 | 0.00 | 81.20 | 1.00 | 6.6 | 0 |
| VIM | N = 20 | N = 11 | ||||||
| MIC50 | 16 | ≤0.03 | ≤0.03 | 32 | 0.5 | >32 | 16 | 16 |
| MIC90 | >32 | 0.5 | 0.06 | >32 | 4 | >32 | 32 | 64 |
| % Inhibited | 35.00 | 100.00 | 100.00 | 0.00 | 100.00 | 0.00 | 45 | 0 |
AVI, avibactam; CAZ, ceftazidime; IMP, imipenem; FDA, Food and Drug Administration; FEP, cefepime; MEM, meropenem; REL, relebactam; TAN, taniborbactam; VAB, vaborbactam; XER, xeruborbactam. MIC50 and MIC90 for xeruborbactam alone were 16–32 µg/mL and 32–>32 µg/mL, respectively, for all the subsets of isolates.
% inhibited at the following concentrations: meropenem, ≤8 µg/mL; meropenem/xeruborbactam, ≤8/4 and ≤8/8 µg/mL; cefepime, ≤8 µg/mL (FDA susceptible breakpoint); cefepime/taniborbactam, 8/4; ceftazidime-avibactam, ≤8/4 µg/mL (FDA susceptible breakpoint); imipenem/relebactam, ≤1/4 µg/mL (FDA susceptible breakpoint); meropenem/vaborbactam, ≤4/8 (≤8/8) µg/mL (European Medicines Agency susceptible breakpoint).