Table 1.
Mechanisms detected among ceftolozane/tazobactam, ceftazidime/avibactam or imipenem/relebactam resistant strains from the 2022 study.
| Resistance mechanism/mutations | Ceftolozane/tazobactam resistant, n = 53 (%) | Ceftazidime/avibactam resistant, n = 56 (%) | Imipenem/relebactam resistant, n = 39 (%) |
|---|---|---|---|
| ESBL/Carbapenemases | 29 (54.7) | 16 (28.6) | 30 (76.9) |
| ESBL GES-1 | 4 (7.5) | 2 (3.6) | 1 (2.6) |
| Carbapenemases | 25 (47.2) | 14 (25.0) | 29 (74.4) |
| GES-5 | 9 (17.0) | 0 | 13 (33.3) |
| MBLs | 16 (30.2) | 14 (25.0) | 16 (41.0) |
| Narrow spectrum OXAs (only) | 3 (5.7) | 2 (3.6) | 0 |
| oprD | 23 (43.4) | 32 (57.1) | 18 (46.2) |
| ampC regulators (dacB, ampD, ampR) | 29 (54.7) | 29 (51.8) | 19 (48.7) |
| ampC (Ω-loop) | 8 (15.1) | 7 (12.5) | 0 |
| mexAB-OprM regulators (mexR, nalC, nalD) | 16 (30.2) | 31 (55.4) | 13 (33.3) |
| ftsI (PBP3) | 1 (1.9) | 4 (7.1) | 2 (5.1) |
| galU | 1 (1.9) | 3 (5.4) | 2 (5.1) |