Table 1.
Tests for adaptive resistance to cefiderocol performed on 30 carbapenem-resistant Acinetobacter spp. isolates with the new protocol adapted from that described by Choby et al. [10].
| CFD 0 μg/mL |
CFD 16 μg/mL |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Isolate | Origin | Species | Carbapenemase | Resistance genes | ID (mm) |
MIC (mg/L) |
ID (mm) |
MIC (mg/L) |
||
| 18–24 h | 48 h | 18–24 h | 18–24 h | 48 h | 18–24 h | |||||
| A1 | Madagascar | A. baumannii | OXA-24 | AmpC, TEM | S (22) | S (21) | S (0,5) | R (15) | R (13) | R (32) |
| A2 | Mainland France | A. baumannii | OXA-24 | AmpC | S (24) | S (24) | S (0.25) | R (16) | R (11) | R (16) |
| A3a | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (22) | S (22) | S (2) | S (18) | S (18) | S (2) |
| A3b | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (21) | S (20) | S (2) | S (21) | S (19) | S (2) |
| A4 | Mayotte | A. baumannii | OXA-23 | – | S (23) | S (23) | S (0.25) | R (16) | R (16) | R (8) |
| A5 | Comoros | A. baumannii | OXA-58 | – | S (27) | S (27) | S (0.06) | S (32) | S (32) | S (0.06) |
| A6 | Ivory Coast | A. baumannii | OXA-58 | – | S (22) | S (22) | S (0.25) | S (17) | S (17) | S (0,03) |
| A7 | Mainland France | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (19) | S (18) | S (1) | R (11) | R (6) | R (16) |
| A8 | Mayotte | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (24) | S (21) | S (1) | S (20) | R (15) | R (16) |
| A9 | Reunion Island | A. baumannii | OXA-72 (OXA-24 type) | – | S (25) | S (24) | S (0.125) | S (25) | S (20) | S (0.5) |
| A10 | Madagascar | A. baumannii | OXA-23 | AmpC | S (20) | S (19) | S (0.25) | R (12) | R (7) | R (16) |
| A11 | Madagascar | A. baumannii | OXA-23 | AmpC | S (20) | S (19) | S (1) | R (13) | R (8) | R (8) |
| A12 | Madagascar | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (22) | S (21) | S (2) | R (6) | R (6) | R (16) |
| A13 | Mauritius | A. baumannii | OXA-23 | AmpC | S (20) | S (19) | S (2) | S (18) | R (14) | R (16) |
| A14 | Reunion Island | A. baumannii | OXA-23 | AmpC | S (21) | S (18) | S (0.5) | S (14) | S (21) | S (0.25) |
| A15 | Reunion Island | A. baumannii | OXA-23 | AmpC | S (23) | S (23) | S (0.5) | S (30) | S (26) | S (0.125) |
| A16 | Reunion Island | A. baumannii | OXA-24 | AmpC, TEM | S (22) | S (20) | S (1) | S (23) | S (21) | S (0.5) |
| A17 | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (20) | S (19) | S (2) | R (16) | R (14) | R (16) |
| A18 | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (26) | S (20) | S (0.25) | R (10) | R (10) | R (16) |
| A19 | Madagascar | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (28) | S (25) | S (1) | R (8) | R (8) | R (8) |
| A20 | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM, ArmA | S (25) | S (24) | S (0.5) | R (10) | R (12) | R (8) |
| A21 | Mauritius | A. baumannii | OXA-23 | ArmA | S (25) | S (24) | S (0.25) | R (14) | R (14) | R (8) |
| A22 | Madagascar | A. baumannii | OXA-23 | PER-7, ArmA | R (12) | R (12) | R (8) | R (8) | R (8) | R (16) |
| A23 | Mainland France | A. baumannii | OXA-23 | ArmA | S (25) | S (25) | S (0.25) | R (16) | R (14) | R (4) |
| A24 | Mayotte | A. nosocomialis | OXA-420 (OXA-58 type) | – | S (21) | S (21) | S (0.5) | S (23) | S (23) | S (1) |
| A25 | Reunion Island | A. baumannii | OXA-23 | AmpC, ArmA | S (21) | S (19) | S (0.5) | R (14) | R (14) | R (8) |
| A26 | Reunion Island | A. baumannii | OXA-23 | AmpC, TEM | S (21) | S (19) | S (0.5) | R (16) | R (16) | R (8) |
| A27 | Madagascar | A. baumannii | OXA-23 | AmpC, TEM | S (22) | S (19) | S (0.5) | R (14) | R (14) | R (32) |
| A28 | Mayotte | A. ursingii | NDM-1 | – | R (14) | – | R (4) | – | – | – |
| A29 | Reunion Island | A. baumannii | NDM-1 | – | R (11) | – | R (16) | – | – | – |
| A30 | Mayotte | A. baumannii | NDM-1 + OXA-23 | - | R (8) | – | R (32) | – | – | – |
Resistance to cefiderocol was detected in all NDM-1 (3/3) and OXA-23+PER-7 isolates in standard AST. Adaptive resistance to cefiderocol was detected in 84.2 % (16/19) and 50 % (2/4) of OXA-23 and OXA-24-type isolates, respectively.
MIC: minimum inhibitory concentration; R: resistant; S: susceptible; ID: inhibition diameter.